San Juan Solstice 50M; A most beautiful run cut way too short

“Joy to you, we’ve won”, the final words uttered by Philippides upon running from Marathon to Athens to announce the victory over the Persians, circa 490 BC.  Philippides was a professional day-long runner delivering urgent messages.  He is an inspiration for ultra runners — he ran first to Sparta to plea for help (240 km over two days), and then ran the 40 km from Marathon to Athens before expiring.

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Top of Handies Peak, San Juan Mountains, early June, 2009. The view is to the southeast, and you can see above timberline for 35 miles.

Calderas, collapse, karats, and cannibals, oh my!  The tiny town of Lake City in southwestern Colorado is the home to a magnificent mountain ultra, the San Juan Solstice 50 miler (SJS50).  Lake City is the epicenter of unbelievably beautiful high mountains, amazing geology, mineral and mining history, and only a few miles from the most infamous episode of cannibalism in the old wild west.  In my opinion the San Juan Mountains are the most beautiful in the world, and the mining history has drawn me to the range for 50 years; the opportunity to run a long race through the mountains I have known was something incredibly special that I just had to do (even if I was only marginally qualified for the extreme course!).

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Michelle Hall, my wife, on her first 14er Handies Peak. Over her shoulder Uncompahgre and Wetterhorn (more 14ers) are visible. Handies is a couple of miles southwest of the SJS50 course.

I first visited the San Juans with my father on a mineral collecting expedition in the early 1960s.  Although I have no real memory of that adventure, I know that it was the first of more than 50 trips we would take before I left home for college.  I visited every mining camp, large and small, across the San Juans looking for mineral treasure.  I found silver, gold, rhodochrosite, great quartz crystals, galena, hubnerite, and artifacts galore. But mostly, I found a place that inspired and thrilled me, and connected with my soul.  The San Juans are no longer a “hidden gem”; they are visited by more than 150,000 people every year.  Telluride has become a major ski resort and playground of the rich.  There are dozens of companies that provide jeep tours to some of the most remote and rugged corners of the range, and sometimes in the summer there are more than 500 ATVs ferrying people to vistas they could barely imagine before they got to the San Juans.  However, despite its growing popularity, the San Juans are still a wilderness, and there are ample opportunities for solitude and reflection — along with climbing, camping, running, and yes, even mineral collecting.

lookingforsilver

Collecting minerals. My grandson’s first mineral collecting trip was to TomBoy located in the San Juans above Telluride. He was 2 and half years old, and found lots of rocks…and a taste of the world’s most beautiful mountain range.

The San Juans are where I took my then-to-become wife on our first “very serious” date.  Once she camped above timberline, and pounded on rocks looking for silver, and had to purify water before breakfast, we knew that we were right for each other.  She saw Cement Creek, Cinnamon and Stoney Pass and the ghost town of Animas Forks before she met my parents.  Years later we returned for a celebration of an anniversary and she climbed her first 14er, Handies Peak.  Later my son would also climb his first 14er there, and it transformed him into a “mountain man”.

Lake City is on the north-central flank of the San Juans, and is less well known than the “big three” mining towns that brought much fame to the area:  Silverton, Ouray, and Telluride.  However, Lake City is just as historic, and is only a few miles – as the crow flies – from 5 peaks that top 14,000 feet. The San Juan Solstice 50 started as the Lake City 50 miler back in 1995.  The terrain is spectacular, but also poses challenges for snow pack and summer lightning storms – much of the course is above timberline. In the early part of last decade the race assumed its modern name, and the goal of running close to the solstice became a mantra.  The SJS50 is extremely popular, and requires runners to qualify and signup for a lottery for the 250 available spots.  The lottery and wait list adds drama to the hopeful runners, but the real challenge is waiting to see if the snow pack cooperates with the third week in June.  In 2015 it was touch and go – an amazing wet late spring kept the high country under a thick white blanket.  Snows finally began to melt in mid-June – and boy did they melt, sending roaring runoff down the drainages.  This set the stage for a true adventure – a 50 mile run with more than 12,800 feet elevation gain and loss, a low point of about 8,700 ft elevation, and an average elevation of approximately 11,000 ft, snow fields, and 9 stream crossing with churning melt waters.  What could possibly go wrong?

Well, it turns out lots can go wrong – flat tires on 4WD roads, warning for missing 25 mile/hour speed limits, and most unfortunately, a bad trip on a downhill run that ends a race early.  However,  the SJS50 is now a life challenge for me.

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Artifacts from the Ute and Ulay mines, located just beyond Alpine Gulch. In the early part of the 20th Century there was a major struggle between newly formed unions and mine management that played out across the mining camps of the Southwest. Pictured are two union ribbons and a ceremonial “sliver slug” stamped “Ulay” (the slug is about 2 inches across). These artifacts are from the collection of a close friend, Dave Bunk. The history of the Lake City is really about the miners and mines – and what is left today are these wonderful artifacts. Jesse LaPlante photograph.

There’s gold in them thar hills (with a shout out to Mark Twain)

I have written several articles on the San Juans – some for technical journals, and some for more popular literature.  Recently, Gloria Staebler and Lithographie published a monogramThe San Juan Triangle of Colorado; Mountains of Minerals that captures the spirit of the geology and the wonderful minerals.  From my writing in the monogram I attempt to tell the tale of the 8th wonder of the world.

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Lithographie monographie on the San Juans (http://www.lithographie.org/bookshop/the_san_juan_triangle.htm)

The San Juan Mountains are a spectacular range of towering and rugged peaks that cover an area larger than the entire state of Vermont –  25,000 sq km of alpine bliss in southwestern Colorado. The range stretches from Creede in the northeast to Durango in the southwest; the San Juans are home to 14 peaks over 14,000 feet in elevation and  hundreds of peaks that top 12,000 feet.  The topography is extraordinarily steep, and much of the range is above timberline.  The imposing landscape was shaped by some of the most violent volcanic eruptions known in geologic history.  Between 35 and 26 million years ago huge volcanic centers rose and collapsed and erupted 10s of thousands of cubic km of rhyolitic and andesitic tuffs.  The scared landscape that remained was full of factures and faults that would later localize the magmatic fluids that deposited the ore bodies of some of Colorado’s richest mining districts:  Creede, Summitville, Silverton, Ouray, Telluride, Rico, and of course, Lake City.

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The volcanic centers of the San Juans. The western-most center is a series of calderas that formed over a 5 million year period nearly 28 million years ago. The initials “LC” denotes the Lake City Caldera, home of the SJS50.

The extraordinary episode of volcanism that created the San Juan Mountains began at the end of the Eocene (a geologic epoch 56-34 million years ago).  More than 30 centers of volcanism formed through out southern Colorado and northern New Mexico in what is known as the Mid-Tertiary Ignimbrite Flare-Up.  These volcanoes probably looked like stratavolcanos that form above subduction zones (eg, Mount Rainier and Mount Fuji) but they produced far more voluminous eruptions.  Initially, the eruptions produced andesites and explosive ash falls, but starting about 30 million years ago huge sheets of pyroclastic flows were erupted.  The pyroclastic flows are welded tuffs known as ignimbrites. These flows are unparalleled in size; within the San Juans there are at least 22 flows that are larger than 100 cubic kilometers.  The only way to explain these flows is to assume nearly continuous eruptions for dozens of years.  The eruptive centers ultimately collapse forming large calderas. The largest eruption known in the geologic record occurred in the San Juan Mountains at the La Garita Caldera north of Creede (denoted as LG in the figure above).   La Garita produced the Fish Canyon eruption 28 million years ago; the Fish Canyon Tuff was voluminous – more than 5000 cubic kilometers!  The Fish Canyon tuff could fill Lake Michigan!  Equally remarkable, after La Garita erupted the Fish Canyon tuff, the volcanic system continued to be active for 1.5 million years producing at least 7 other major eruptions.

The reason for the Mid-Tertiary Ignimbrite Flare-Up is a subject of geologic debate, but most geologists believe that the volcanism is related to the tectonics along the west coast of North America.  The Laramide Orogeny, which resulted in the uplift of much of the Rocky Mountains along an arc from Canada to New Mexico, is thought to be related to the subduction of the Farallon oceanic plate beneath North America.  The Farallon plate was quite young geologically, and thus buoyant.  This likely resulted in a shallow angle of subduction, which caused an uplift of the entire western US.  About 35 million years ago the last bit of the Farallon plate was subducted resulting in a major re-ordering of plate tectonics on the western edge of the North America.  Without subduction, the Farallon plate began to simply sink through the mantle in a process that is known as “slab roll-back”. This allowed very hot mantle to melt large regions of the lower most crust, and created the magma sources for the ignimbrites.  The eruptions of ignimbrites lead to the collapse of the huge calderas throughout the San Juans and developed a structural fabric that would localize much younger volcanic activity, which would give rise to rich mineral districts.

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The Lake City Caldera (from Bove et al., 2001). The high peaks between Henson Creek, which passes through Lake City, and the Lake Fork of the Gunnison River are all volcanic centers that erupted about 22.5 million years before the present.  Collapse of the volcanic center produced an elliptical depression – about 1/2 the diameter of the Valles Grande Caldera near Los Alamos.

In the area defined by the San Juan Triangle (Telluride-Ouray-Silverton, and over to Lake City) there are four collapsed calderas; the Uncompahgre, San Juan, Silverton, and Lake City.  The first three were formed during a time period of 29 to 27 million years ago.  The Lake City caldera was the last to form, at the end of the ignimbrite flare up, 22.5 million years ago.  The geologic record within the San Juan Triangle is complex and difficult to interpret due to the superposition of the calderas and their structural manifestations. The Uncompahgre and San Juan calderas are the oldest; they were active at the same time, and collapsed simultaneously with the eruption of a very large ignimbrite sheet.   The ring faults associated with the Uncompahgre and San Juan calderas form an oblong structure that is about 45 km by 15 km, trending southwest-northeast. The formation of the Lake City Caldera was the last gasp of the Mid-Tertiary Ignimbrite flare up.  The rich ore deposits in the San Juan Triangle were emplaced 5 to 15 m.y. after the calderas formed. This mineralization is classified as epithermal and is associated with minor episodes of magmatic activity.   The base metal deposits contain mainly galena, sphalerite, and chalcopyrite while the precious metal deposits are mainly native gold.  Silver occurs in a suite of exotic minerals that includes tetrahedrite/tennantite, proustite, and pyrargyrite.  Gangue minerals include quartz (most common), calcite, pyrite, pyroxmangite, rhodochrosite, fluorite, and barite.

CapitolCityminerals

Minerals from “Mr. Mesler’s Mine”, which was located in Capitol City, and short distance beyond Alpine Gulch on Henson Creek (about 9 miles from Lake City). From Dave Bunk’s collection (Jesse LaPlante photograph).

There were hints of the great mineral wealth of the San Juans in the earliest expeditions exploring the western US.  In 1848, John Fremont led a privately funded expedition into Colorado to scout a route for an intra-continental rail route along the 38th Parallel. The expedition was a disaster due to an exceptionally cold winter, but an unnamed member of Freemont’s party discovered gold nuggets and flakes near present day Lake City. The exact location of the discovery is not known, but it was probably the Lake Fork of the Gunnison River, and may well have been related to the future Golden Fleece mine, which would become Lake City’s most famous mine 30 years later.  This is the first documented discovery of gold in the state of Colorado, although it was largely ignored.

In 1859 gold was discovered along the Front Range, west of present day Denver. This coincided with the decline of gold mining along the Sierra Nevada of California and created a rush of prospectors to Colorado. This became known as the Pike’s Peak Gold Rush, although the gold discoveries had nothing to do with the famous 14er. The huge influx of prospectors far outstripped the easily won gold in the Denver area, and prospectors fanned out to other parts of the Rockies. In the late summer of 1860 Charles Baker led a party of gold seekers to the San Juans. Baker entered the San Juans along the Lake Fork of the Gunnison River – he walked along part of the course of the SJS50! His party eventually passed over Cinnamon Pass, and discovered gold along the Animas River near Silverton.  There was no putting the genie back in the bottle – mining became the heart beat of the San Juans for a century.  The early years were extremely difficult;  the San Juans were actually part of land the US government had agreed was owned by the Ute Indians, the area was so remote that it was nearly impossible to supply and provision, and the mining season was short and harsh due to the alpine environment.  In 1873 the Brunot Agreement opened the land to mining (the Utes in return received $25,000 annually in royalty, and the right to hunt), and  soon toll roads and narrow gage trains began to “civilize” the area.

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Early cross-section of the Golden Fleece Mine.The upper reaches of the mine assayed at 125 oz of gold and 1250 oz of silver per ton.

The first major mineral discovery near Lake City occurred on August 27, 1871 Henry Henson discovered a rich silver deposit – to be called the Ute-Ulay – along a stream about 3.5 miles from the present location of Lake City. Later this stream would be named Henson Creek (the SJS50 follows Henson Creek for the first 2.5 miles of the course). Once the Brunot Agreement was signed, Henson returned and developed the Ute-Ulay mine, which was a major silver and lead producer (but few mineral specimens exist today – a pity).  This development attracted entrepreneurs of every type; one of these was Enos Hotchkiss who came to build a toll road but instead discovered gold above Lake San Cristobal, a couple of mines south of Lake City.  Hotchkiss did not find much gold at first – in fact his claim was largely based on the obvious color of the rock – anyone with a sprinkling of geologic knowledge just has to gaze up Red Mountain and see the beautiful color of an oxidized cap, and know that there is gold in them thar hills. However, the claim was enough to commit to prospecting, and Lake City was founded on this promise. Eventually the Hotchkiss claim was renamed the Golden Fleece Mine, and became one of Colorado’s most famous.  The early years of the Golden Fleece relied on telluride ores, and there are reports of individual mining carts assaying 50,000 dollars of bullion.  I have been underground at various adits associated with the Golden Fleece looking for rumored veins of hessite, one of my favorite minerals. Alas, like most old San Juan mines, the conditions are deplorable, and one is actually just lucky to get out alive.

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Stock certificate from the Golden Fleece mining and milling company dated 1896. Although the Golden Fleece produced silver, and thus was impacted by the 1893 silver crash, the steady production of gold helped the property make it through the “silver crisis”. Dave Bunk collection.

The news of the Golden Fleece started a “Lake City” rush. By 1880 there were dozens of mines in Carson (along the SJS50 course), Argentum and Capitol City.  The population of Lake City swelled to 2500, and the boom times were full steam.  However, silver soon ran into the buzz saw of politics.  The rich deposits of the San Juans began to push the price for silver bullion down, and western mining barons demanded action.  In 1890 Congress passed the Sherman Silver Purchase Act, which required the US government to purchase $4.5 million dollars worth of silver every month.  This proved to be as unpopular among the Republicans of the day as the Affordable Health Care act today, and was repelled in 1893 – and the price of silver plummeted.  In a few week period the price dropped from $1.50 per oz to 63 cents.  At the time, Colorado produced about 2/3 of all the silver in the country; within 2 years more than 1/2 the silver mines in Colorado – including those near Lake City – were shuttered.  Although the mining industry would eventually recover, the heyday had passed.  Today there is some mining in the Lake City area – for example the Golden Wonder Mine located at the head of Deadman’s Gulch – but mostly there is history of an incredible tough breed of pioneer that has long passed.

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Rhodochrosite, Champion Mine, Dave Bunk collection.  The Champion Mine is located near Cinnamon Pass – the road over Cinnamon Pass was built by Enos Hotchkiss. Jesse LaPlante photograph.

In 1911 Irving et. al published Geology and Ore Deposits near Lake City, Colorado.  In the text is a haunting statement: “Secondary enrichment…led to the formation of the rich bonanzas of ruby silver found here and throughout …”  Oh, to find a pyrargyrite or proustite from Lake City! I have not in 50 years, so I suppose I am happy to run the San Juan Solstice instead.

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Google Earth Image of various points along the SJS50. The course starts in Lake City and head west on Henson Creek, then south up, way up, Alpine Gulch. The course turns towards Redcloud Peak, a 14er, but before arriving there descends into the Lake Fork valley. After crossing the valley the course climbs steeply up to the continental divide, and has 15 miles above timberline.

50 Miles, a clock ticking, and then a trip

Lake City is a small town, and every resident seems to be involved in the race.  The Lake City of my youth was a decaying frontier mining town; like nearly all Colorado mountain mining communities it has been gentrified and is now a destination for outdoor enthusiasts of all sorts. Gentrification came decades later than to Aspen or Telluride, so it is still has the rustic flavor of the early part of the 20th Century.  But make no mistake, expensive vacation homes and a very fine French Chef are now part of the Lake City landscape.  The SJS50 checkin is most of the day before the race – lots of hard core trail runners from all around are wandering the small town park that serves as the start and finish to the race.  It does not take insightful self awareness to immediately recognize that I am not really “like” most of the runners.  However, that is not why I run, and I am truly excited to be in the San Juans.

The final checkin for race begins at 4 am on Saturday, June 27.  I put my drop bags into the piles for a couple of the aid stations, and begin to get nervous.  Visiting various parts of the course the day before I know that it will be wet and muddy, so I have a couple of extra pairs of shoes, lots of socks, and of course, my special energy supplies tucked into my drop bags that proudly displace my name and bib number.  In ultras your bib number is aways assigned alphabetically, so my bag is pretty easy to find (although not as easy to find as my friend Dave Zerkle from Los Alamos….).  At 4:55 a soft bull horn announces that the race will start in 5 minutes.  I hustle into position, but it seems strange to me that runners are still milling around the park or standing in line at the port-a-potties.  Suddenly I hear, with no warning, a growled “GO”, and people are off running.  There are also runners running from the port-a-potties.  I realize that 13 or 14 hours running will not rely on a punctual start.

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The glint of reflective tape and headlamps at 5 am start of the San Juan Solstice. A bit of a chaotic beginning, but a perfect morning.

The first 2.6 miles of the race are up a gravel road along Henson Creek.  There is not much chit-chat, and the sounds I hear are the crunch of 500 feet on the road gravel and mixed with the turbulent roar of Henson Creek bringing snow melt down from the high country.  Dave Zerkle and I settle into a very agreeable pace of a little better than 11 minutes per mile (the specter of 50 miles looms large).  When we arrive at Alpine Gulch we start the real race.  Although we have climbed 500 feet thus far, in the next 6.5 miles we have nearly 4000 feet elevation gain.  The sun is still an hour from lighting the narrow canyon, but there is enough glow to switch off the headlamps.  The creek in Alpine Gulch is churning, but the water is much lower than just a week before. At mile 3.75 we come to the first of 7 (or 8, 9, or 10, but who is counting) crossings of the creek.  The crossing has a rope for assistance, and a number of volunteers to offer advice.  The runners stack up waiting for their chance to jump into the frigid waters…the first step is a doozy, although the water is only a bit above my knees.  Cold, but I am surprised how good it feels!

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The first river crossing along Alpine Gulch. This photo was taken the day before the race, scouting the various segments. The picture does not give a great sense of the water depth, but it is about 2.5 feet here. At some of the higher crossing the water is definitely crotch level.

The course criss crosses the gulch many times, and at each water entry there are volunteers and a rope.  Some crossing are more challenging than others, but every time the runners emerge with soaked shoes, socks and compression sleeves.  I really enjoy the crossings, except they continually bunch the runners.  Dave Zerkle and I are trying to maintain a 20 minutes per mile or better (the average grade on most of the climb is 17%).  For the most part, the running dynamics are such that we can pass the slower runners, and get passed by the occasional faster runner (probably the people that were in the port-a-pottie when the race started).  However, around mile 6 I become quite impatient with the “group-pace” and ask to semi-sprint past a dozen runners.  It is hard work, but rewarded with open trail. A downside is that I lost Zerkle.  The first aid station is located at a small saddle at mile 7.6.  The cutoff time for this station is 7:45 am – in other words, 2hr45min from the start.  Sounds easy, but the climb is tough.  I planned on arriving at 7 am, and I am 6 minutes early.  I feel fantastic, and have visions of a sub-13 hr race.

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View of the south side of Red Mountain from Aid Station #1. The red color that is usually so distinctive is muted in the early morning sun. However, on the ascent up the gulch there are many old mines and the cabins of prospectors past.

Although the aid station is at a saddle, the climbing continues.  I am still moving well, not really tired, and hypnotized by the scenery.  I feel like I am home.  Shortly before summitting at the high point of the first part of the course I catch up to another runner from Los Alamos, Sarah Thien.  She has been battling an injury, and is not her usual rapid self.  We do get to chat a bit, and both marvel that the mountains surrounding us.

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The first climb is nearly over – a pass on the shoulder of an unnamed 13,600 foot peak visible over my left shoulder. The day is spectacular! In the distance I can see Handies and Sunshine Peaks.

Once on the divide I know that the course is going to descend nearly 3500 feet in the next six miles.  All those hard earned feet and inches of elevation gained are soon to be lost, and gravity wins again.  I always have a difficult time shifting gears from climbing to running downhill.  I suppose it is the stiffness of age, but my hips always have to be convinced that it is okay to have strides longer than 10 inches.  After a mile or so I am beginning to hit a stride of 11:30 minutes per mile;  I had hope for 10 minutes per mile, but I am ahead of schedule never the less!

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Sarah Thien running across the divide. The view is towards the west, and the high peaks of Uncompahgre and Wetterhorn can be seen in the distance.

There are a number of snow crossing, but the elite runners have post holed a pathway.  The snow is soft and wet — and slippery – but mostly enjoyable.  At mile 10.5 the snow is behind me, and the steep descent begins.  I am excited and begin to try and sprint.  Disaster strikes at mile 11 – I trip.  I am on a steep trail section and tumble head-long downhill. I land hard on my artificial knee and my right forearm.  The trail is rutted, and I am facedown, feet above my head, unable to get up.  I realize this is bad, but I hope that it is a typical trail run trip where the blood is always worse than the damage.  My dignity is challenged as I try and right myself – a woman runs past as I am still down and asks “did you fall?”  Oh, if only I could have actually answered that question with a response it deserved!

I get up, and start downhill knowing that the Williams Aid Station is only 4.5 miles ahead.  I can’t really run, but I am moving.  Lots of runners now pass me, reminding me that hubris is a nasty sin. I am worried about my knee – being an artificial joint I imagine some horrific breakage.  Hardly likely, but a concern nevertheless. My right foot (below my artificial knee) is totally numb.  Every step feels like I am swinging a club attached to my knee.  Before the fall I was on pace to arrive at the Williams Aid Station at 9:05 am.  Instead I arrive at 9:32.  I check in, and then very reluctantly, drop the race.

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After clean up – once the blood and grim is removed, it does not look so bad. Well, at least the knee. Unfortunately, the day is done.

The medical staff help clean up the wounds, and I get bandaged up.  My wife is at the aid station, and provides the sad sag-wagon ride back to Lake City.  After only finishing 16 miles I am quite depressed.  I look up on the ride in and see two parts of the course I very much looked forward to: Slumgullion and Vickers.

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Michelle standing at the Slumgullion pass point of interest. Over her head is the scarp of the repeated Earthflows.

The Slumgullion Earthflow is one of the most interesting and odd geologic features on the entire run. In the 1870s this strange tongue of yellow chalky debris was identified as a landslide off Mesa Seco (the map below shows the geography of the slide).  It was later recognized that the Slumgullion was not “a landslide” but a series of large scale debris flows that have been active for hundreds of years.  About 1200 years ago the competent rocks on the top of Mesa Seco began to slide down towards the river valley because the underlying rocks, which are heavily altered ignimbrites from the Lake City Caldera complex, were exposed and rapidly eroded.  The first flow damned the river and formed a prototype Lake San Cristobal.  Eventually the river cut through this old debris flow and drained the lake, only to see two other episodes of mass wasting, one 700 years ago, and most recently, 300 years ago (and this flow is still active). The distance from the head of the flow – the scarp on the cliffs of Mesa Seco – to the toe is about 7 km, and 170 million cubic meters of material are contained within the scarp.

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The Slumgullon – a large landslide due to the collapse of steep cliffs of decomposing volcanic tuff.

There is a section of the slide that remains active.  At one time it was a standard geology student training exercise to measure downward movement with seasonal surveys.  Today the movement is measured with SAR (synthetic aperture radar).  The image below is from a pair of NASA overflights, and is colored to show the motion over a one week period in 2011.  The red/purple colors show the most rapid motion, about 4 inches per week.

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SAR image of the Slumgullion Earthflow. The slide is outlined in red, and the colors are constructed from the fringes of the differences between two radar images. The slide a few hundred meters above the SJS50 crossing is slowly moving downhill.

Although the Slumgullion slide is strange, it pales in weirdness to the last section of the course – the climb up Mesa Seco.  The SJS50 course is very close to the Alferd (sometimes written Alfred) Packer cannibalism site – in fact we are probably running on the very ground that Packer’s victims camped on at back in 1874. Packer – with no real experience, but a gift for tall tales – guided 5 men to the area in February (the middle of winter!) to look for gold.  It seems they were prospecting very close to the future Golden Wonder Mine (it is in Deadman Gulch, named for the Packer victims), but they became snow bound and quickly ran out of supplies.  There are many versions of what happened next, but it is clear that Alferd killed and ate his companions to survive.  For this reason I believe that the final aid station, named “Vicker’s” for the nearby ranch should actually be called Packer, and there should be bacon there…. I ponder what it must have been like to be in the San Juans 140 years ago.  I often think I was born 100 years too late, and could have been a naturalist.  Then I recall the amusing tale of the Hinsdale County Judge that presided over the trial of Packer and sentenced him to be hanged (the sentence was eventually overturned because Alferd ate his victims while Colorado was still a territory, and cannibalism was not a crime in the territory….really!); was reputed to have said: “Stand up yah voracious man-eatin’ sonofabitch…. When yah came to Hinsdale County, there was siven dimmycrats. But you, yah et five of ’em, goddam yah….Packer, you Republican cannibal, I would sintince ya ta hell but the statutes forbid it.”  Ah politics, they have not changed in 140 years.

After I get cleaned up and rebandaged, I go to the finish line and wait for all my friends to finish.  As the first runners come in I am struck how most look very different than runners after a 50K race.  Here they are far more tired, looking thankful for the finish instead of happy.  Nearly every runner I know tells a tale of how difficult the conditions were this year and how hard, very hard, the run was.  I think of Philippides who’s legend inspires ultra runners — giving it all, raising their arms in victory as they cross the finish line, and crumpling to the ground in exhaustion.  I suspect even Philippides would find the SJS50 challenging.

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A butterfly at Alpine Gulch. Simple beauty everywhere.

My morning after the race I have come to grips with my race-interupted.  I have decided that this is something I can not leave undone. I will return in 2016 – in fact, it will be the focus of all my training for the next year.  I also wonder how I can make the San Juans my home.

The Riff of the Rio Grande Rift: Running in the Pecos Wilderness and up Santa Fe Baldy

Both the man of science and the man of action live always at the edge of mystery, surrounded by it – J. Robert Oppenheimer, who was appointed the Director of Los Alamos Laboratory in November 1942.

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View of a late spring storm over the Sangre de Cristo mountains viewed from Los Alamos (photo by Jim Stein, Los Alamos photographer extraordinaire, May 26, 2015). The peak in the center-left is Santa Fe Baldy (elevation 12,632 feet).

The town of Los Alamos sits high above the Rio Grande River on the Pajarito Plateau.  The location of the town will always be associated with the Jemez Mountains and the spectacular Valles Caldera; however, the view from the town is always to the east, across the Rio Grande Rift, and towards the Sangre de Cristo Mountains.  The Sangre are the southern most range of mountains that are part of the Rockies, and the view from Los Alamos is dominated by a series of rugged high peaks – Truchas, Jicarita, Sante Fe Baldy Peaks all top 12,500′ – these rocky spires guard the Pecos Wilderness, one of the Jewels of unspoiled New Mexico.

The creation myth of the Los Alamos often casts J. Robert Oppenheimer as selecting the isolated and rugged Pajarito Plateau for the project Y laboratory because of a connection with the Los Alamos Ranch School, a boy’s college prep school. However, that is incorrect – indeed, Oppenheimer recommended and lobbied for a laboratory in New Mexico because of his affection for the area.  But that attachment was with the area that would become the Pecos Wilderness Area.  In 1922 Oppenheimer and his brother Frank visited the Pecos Valley and loved it – so much so, that the brothers first rented, and eventually bought, a ranch along the Pecos River which they named “Perro Caliente” (the legend is that when Oppenheimer found the land for sale he shouted “hot dog”, and the name seemed logical for the new ranch).  When General Groves and Oppenheimer visited New Mexico to locate project Y the preferred site was near Jemez Springs.  However, Oppenheimer convinced Groves that the high cliffs would make the scientists claustrophobic, and thus, unproductive.  The next site visited was the Los Alamos Ranch School, and Oppenheimer beamed with joy at the view towards the Sangre de Cristo mountains, and exclaimed that the scientists would be inspired by the vast vista.  Of course, to the is day, the scientists — at least this one — remain inspired by the magnificent mountains.

attheranch

J. Robert Oppenheimer and E.O. Lawrence at the Oppenheimer Ranch along the Pecos River in the Sangre de Cristo Mountains. Oppenheimer often rode a horse from his ranch up to Lake Katherine just below Santa Fe Baldy.

The high mountain peaks of the Sangre are accessible by a number of trails that are only 35 miles from Los Alamos.  These trails allow great entry into the high country for trail running (and hiking!); several of the trailheads are located at the Santa Fe Ski Basin, and are gateways to runs of 20, 30, and even 50+ miles at elevations that never drop below 10,000′. This is a perfect training ground for the ultras like the San Juan Solstice 50 Miler (June 27, only 2 weeks away) — so off went about 10 runners from Los Alamos and Santa Fe on June 13 to get some quality high altitude climbing and descending, and tasting the ever changing alpine weather.

Zerkle.done

Dave Zerkle, at the Sante Fe Ski Basin after a wet run up Santa Fe Baldy.

The geologic story of Santa Fe Baldy

New Mexico is an arid state. In fact, it has the lowest water-to-land ratio of any of the 50 states in the US, and more than three quarters of the few lakes that exist are actually man made reservoirs. Despite this lack of water, or perhaps because it is so scarce, the human history of the state is dominated by a narrow ribbon of water that bisects New Mexico, the Rio Grande River.  The Rio Grande is long, but not wide, and only in New Mexico would the name “Grande” be applied to this river.  The stream gauge at Otowi Bridge — on the hiway route from Los Alamos to the Sangre de Cristo Mountains – read 2500 cubic ft per second the morning of June 13, 2015 (the Mississippi River flow was 220 times larger at St Louis this morning).  However, this modest flow supports the state, and 75 percent of the state’s population lives within 50 miles of the Rio Grande.

The Rio Grande River is also a remarkable geologic marker. The headwaters are in the San Juan Mountains of Colorado, and entire course of the river through New Mexico follows a topographic depression that traces the Rio Grande Rift (RGR).  The RGR is relatively uncommon geologic phenomena, a continental rift (there are only three others in world), and it represents a stable continental plate slowly being torn apart; or more correctly, stretched apart.  The RGR stated about 25-30 million year before the present, and represents the end stages of extensive crustal extension throughout the southwest. The crust between the California-Nevada border and the Tucson, Arizona extended by as much as 50% during this time. The RGR is presently opening at less than 2 mm per year, but integrated over millions of years this has created a “hole” where the crust has been stretched apart. This hole is instantiated by a series of basins that have been filled with the sediments transported down the Rio Grande River.

Basins

The trace of the Rio Grande Rift is marked by a deep graben, which is mostly filled with sediments that have washed down the Rio Grande River over the last 25 million years. Los Alamos sits on the western margin of the Rift, and the Sangre de Cristo Mountains are along the eastern margin. Between Los Alamos and Sante Fe Baldy is the Espanola Basin.

The figure above shows the largest of these basins, including the location of the Espanola Basin which sits between Los Alamos and Santa Fe, and is more than 10,000 ft deep and filled with ancient river sediments.  The flanks of rifts are almost always elevated relative to pre-opening of the rift.  This may seem counter intuitive given that the opening of the rift creates a “hole”.  However, the opening of the rift is usually associated with ascending hot mantle material, which “lifts” the region overall.

riftdynamics

Conceptional cartoon for continental rift dynamics. Ascending hot mantle materials raise the elevation, and as the crust is extended a rift valley forms. The flanks of the rift are often uplifted high mountains with steep faces sloping into the rift valley.

This is the case for the entire eastern flank of the Rio Grande Rift in northern New Mexico.  The present topography of the Sangre de Cristo Mountains owes its existence to the opening of the RGR.  The Sangres are an ancient mountain range and certainly were part of a proto-Rocky Mountains.  However, studies of erosional surfaces indicate that 35 million years ago the prominence of the Sangres was only a thousand feet.  Opening of the rift allowed the rocks of the range to rise to their present elevation and develop and prominence of over 7,500′.

pecosmapRobertsonMoench1979

Geologic map of the Pecos Wilderness Area. The western margin is a block of plutonic granitic rocks that have been uplifted during the opening of the Rio Grande Rift. This block contains all the high peaks of the Sangre de Cristo range (from Robertson and Moench, 1979).

The core of the Sangre de Christo Mountains in the Pecos Wilderness area are Precambrian plutonic granites (and granitic gneiss).  In the figure shown above, the large elongate block on the western side of the map shows the extent of this plutonic rocks which are approximately 1.6 billion years old.  They are fragments of the original North American crust that were probably formed 5 to 10 km beneath the surface of the Earth.

The topography from the Jemez Mountains to the Sangre de Cristo Range are due to the dynamics of the Rio Grande Rift.  In fact, the entire landscape of the New Mexico has been influenced and shaped by the RGR.  As a geologic architect, the rift is Frank Lloyd Wright.

lookinguptobaldy

Looking up at Santa Fe Baldy from the Winsor Trail just beyond the Rio Nambe crossing. 2000 feet to climb in about 2.5 miles. Steep and sweet.

Sky running in the Sangre 

The Mountain Trail Series group (meaning Dave Coblentz from Los Alamos) organized a trail run for the high country of Pecos Wilderness.  The run (route shown below) climbed several of the peaks, and included some cross-country (no trails).  Several of the less ambitious (I am actually always ambitious, but my athletic ambitions do not match my actual skill) chose to run a section of the course.  The IDEA was to run up Santa Fe Baldy and then loop back over Lake Peak.

Coblentz.map

Map of the “course” for Beyond Baldy, a Mountain Trail Series Event. A group of us chose a slightly less ambitious versions that topped Santa Fe Baldy and Lake Peak without venturing cross country to Redondo Peak.

The forecast called for rain, but gave a glimmer of hope that the precipitation would hold off until noon.  However, at the start of the run at 7 am it was clear that a storm was brewing.  The Winsor Trailhead has an elevation of about 10,200′, and that is the low point of the run. The trail starts with a steep, switchback climb – about 500 feet in the first half mile – and by the top of first segment the fast runners have baked me off the end of the group.  This is good because it gives me time to look at the rocks and not feel pressure.  The trail is soft and not particularly rocky, but there are ample outcrops to see large blocks of granitic gneiss/schist glistening in the morning light.  The schist is rich in mica – and it is a marvel to imagine that this delicate mineral could last for over a billion years!

Once the trail enters the Pecos Wilderness boundary it is fairly flat for about 4 miles.  Easy running, along with a couple nice stream crossings.  When you arrive at the Winsor-Nambe trail fork the serious business of climbing begins.  However, today is a training run, so the pace is steady and easy. About 1/2 hour from the summit of Baldy we can see the fast runners along the ridge nearly to the top.

terryontop

Standing on the summit of Santa Fe Baldy. Behind me is the silhouette of Truchas Peak and ridge, about 30 miles north. There is no sunshine this June morning.

The views from the summit of Santa Fe Baldy are usually breathtaking.  However, today, hanging clouds at the front edge of a storm surround the ridges and obscures any distant vistas.  There is a fine view down to Katherine Lake, which still has some ice!  Lake Katherine is within a cirque on the northeast side of Baldy.  This cirque was formed by alpine glaciers that were extensive about 11,000 years ago.  Based on the number and character of the cirques on Baldy and Lake Peak the annual average temperature of the region must have been about 10 degrees F less than today. Katherine Lake is the largest alpine lake in the New Mexico (although small), and has an unbelievable connection to J. Robert Oppenheimer – he named it.  The lake is on maps that were produced before 1930 with no name, but in 1933 a map was produced that included the name “Katherine Lake”, and a reference to Oppenheimer as the namer.  It turns out that on J. Robert’s first visits to Pecos he became infatuated with a young woman of an old New Mexico family, Katherine Chaves.  His affections were apparently unreturned (it would appear that Oppenheimer was a nerd as far as the opposite sex was concerned, and he may have never even approach Chaves), but on his many trips riding horses in the Pecos came to love the small lake beneath Baldy, and wistfully named it Katherine Lake.

lookingatkatherine

a view from Santa Fe Baldy down to Katherine Lake. There was still a thin covering of ice on most of the lake, extremely unusual for June!

After a short break at the summit it was clear that it would soon start storming, and we began the descent down Baldy back towards Lake Peak.

zerkle

Dave Zerkle on the flank of Santa Fe Baldy. Over his right shoulder is Lake Peak and the cirque that contains Nambe Lake.

Soon there was grapple falling – then hail – then rain – then hard hail.  All those things are just an enjoyable part of trail running.  However, they were accompanied by thunder and lightning, and it was prudent to get off the exposed ridge lines as fast as possible. At this point I am reminded that being an old, slow runner has advantages – feet close together makes for less potential drop during a close-by lightning strike!

lightning

Most lightning fatalities are NOT from direct strikes. Rather, they are from close by strikes and the fact that humans make a grounding loop. Strangely, if your feet are together the potential drop from one foot to the other is much lower than if you have a wide stance….So, run with a shuffle.

The down pour dictated a change of plans, and we had to delay the run up to Lake Peak for another day.  Nevertheless, the run up Baldy is a great adventure!

moonrise

Moonrise over Santa Fe Baldy seen from Los Alamos. Another outstanding photo from Jim Stein. Full moon, mid-April, 2015.

Super Volcano in the Backyard: The Valles Caldera Marathon

Some things will never change. Some things will always be the same. Lean down your ear upon the earth and listen…..All things belonging to the earth will never change–the leaf, the blade, the flower, the wind that cries and sleeps and wakes again, the trees whose stiff arms clash and tremble in the dark, and the dust of lovers long since buried in the earth–all things proceeding from the earth to seasons, all things that lapse and change and come again upon the earth–these things will always be the same, for they come up from the earth that never changes, they go back into the earth that lasts forever. Only the earth endures, but it endures forever – Thomas Wolfe, in You Can’t Go Home Again (1940).

fromtheplane

Ariel view of the Valles Caldera and Jemez Mountains. This view is taken from a small plane at an elevation of 14,000′ looking south-southeast across the Valles Caldera. Photo by L. Crumple. (Click on pictures to get full sized view)

There are numerous influences in my childhood that propelled me to a career in the Earth sciences;  a father that loved to prospect and collect minerals, hundreds of family camping trips to the most interesting geologic province in the world (the Rocky Mountains!), and a progressive high school that offered a rich course in geology.  In hindsight, one of the most important influences was the fact that I grew up on the flank of a huge volcanic complex, the Jemez Mountain Volcanic Field.  The terrain of deep canyons, flat mesas, and a beautiful grass valley, the Valle Grande, surrounded by ponderosa pine covered peaks frame my childhood memories and help define home for me. The Jemez Mountains rise some 5000′ above the Rio Grande River and are remnants of a massive volcanic system that experienced two “super” eruptions about 1.4 million years ago.  The Jemez don’t really look like a volcano today if one’s idea of an active volcano is Mt. St. Helens or Kilauea – it is a large circular depression surrounded by the high peaks that once where the steep slopes of a series of craters that spewed forth hundreds of cubic km of hot ash. The figure at the top of this column is an aerial view of the Jemez, and the depression and surrounding peaks protect a series of valleys that once were filled with rain water after the great eruptions.  These valleys, or valles in spanish, are a unique feature of the Jemez. These mountains shaped me in many ways.  Out my back door was a riveting geologic panorama that provided an open invitation to explore nature.  Although most of the Valle Grande proper was off limits during my youth – it was a working cattle ranch that we just called “The Baca” in recognition that it was part of a old Land Grant called Baca Location Number 1 –  the surrounding mountains and forest lands were our play ground.

vallesgrande

View from within the Valle Grande to the west. The high peak is Redondo Peak, and the smaller rise on the righthand shoulder is Redondito Peak. The Valles Caldera marathon traverses around the base on Redondo on the edge of the Valles.

I learned about hiking, camping, wildlife, and calm call of nature.  I even learned some things about mineral collecting; in general, there is not much “mineral wise” in the Jemez, with the one exception. My first vehicle was a hand-me-down four wheel drive Toyota Land Cruiser.  Not many things worked on it (including the gas gauge which more than once left me stranded), but it did afforded me the freedom to explore the Jemez on my own.  My favorite trip was to the ghost town of Bland, a short-lived gold mining center located a few miles south of the Valles Caldera.  The mineral deposits were not formed by the volcanic processes that built the Jemez Mountains, but were from an earlier epoch of magmatic activity that injected quartz dikes into surrounding bedrock.  The Jemez volcanics covered these dikes, and later, through the randomness of erosion, were exposed in a narrow canyon (Bland Canyon).  In 1893 the first of a dozen claims was staked on these dikes for gold and silver.  A rush ensued, and soon a town was built and the population grew to more than a 1000 people.  The town was named Bland in honor of Richard Bland who had advocated for the governmental purchase of silver, and in turn, that bullion was minted into silver dollars.  The Bland act, and further requirements for the government to purchase silver (in particular, the Sherman Silver Purchase Act) were repealed in 1893 causing a collapse in silver prices — just as the mines in Bland were being discovered.

bland.1900

The boom town of Bland, circa 1900. Many of these same building were identifiable in the early 1970s when I searched for artifacts (with some success) and traces of gold or silver (without any success!). Unfortunately, all traces of Bland were destroyed in the 2011 Las Conchas fire – it is even impossible to find most of the old mine dumps.

I drove to the ghost town of Bland every chance I got in the early 1970s.  There was a “back way” in that required delicate 4WD navigation;  I was rewarded with a harrowing journey through the Jemez Mountains, and a chance to search through all the old building looking for artifacts and the mining dumps for some sign of gold or silver.  Mostly my searches were unsuccessful, but I had taste of the treasure hunter.

insulator

An insulator I collected near Bland in the early 1970s. The screw on glass has a patent date of 1893.

In the year 2000 the Federal Government purchased the “Baca” and it became the Valles Caldera Natural Preserve.  The charge of the Preserve was to remediate the effects of logging and cattle/sheep grazing, and eventually make the Valles Caldera a multi-use facility.  Although access is still carefully controlled to the Valles it has become the home to several special events.  In 2006 it became the site of a trail run – first a marathon, and later a half marathon and 10 km run were added.  The course has changed over the years, and a fire in late May of 2013 forced a change to a partial out-and-back route. The chance to run in a certified super volcano, only a few miles from my house is a huge draw – the Valles Grande Caldera Runs are a geologist’s dream.

IDL TIFF file

A recent NASA satellite image of the Valles and Jemez Mountains (click on the map to get a large, and clearer view). The circular depression of the caldera is obvious; left of the depression (east of the caldera) is Los Alamos. The brown-gray color is due to the denudation of the ponderosa pine and other vegetation after the 2000 Cerro Grande and 2011 Las Conches fires.

The volcano in my backyard

The Jemez Mountains and Valles Caldera are a spectacular sight from space. The satellite image above shows the circular depression that is about 13 miles across that formed after a series of very large eruptions of ash-flow tuffs emptied a large, shallow magma chamber.  Nearly 800 cubic km of ash were propelled from various volcanic vents, and the “hole” left by this erupting ash caused the volcanic edifice to collapsed back into itself producing a broad valley. Later, renewed magmatic activity pushed rhyolitic magmas up through the fractures formed during the collapse, producing a ring of domes breaking up the original valley into smaller, isolated valleys.  The largest of these magma extrusions, known as resurgent domes, is Redondo Peak, which has an elevation of 11,258′ and towers some 2500′ above the valley floor.  Redondo Peak is not a volcano – it was not “erupted” but extruded from the magma chamber beneath the Valles much like tooth paste would be extruded from a tube as it is slowly squeezed.

Vallea cauldera section 700

Geologic evolution of the Valles Caldera. The Valles volcanic center was active for 12 to 13 million years before a pair of major eruptions (1.5 and 1.2 million years before the present) caused the edifice of the volcanic system to collapse forming a large circular depression. Eventually this depression was dotted with a number of volcanic plugs or domes, forming the mottled landscape of Valles Caldera today (Image from the New Mexico Museum of Natural History).

The Valles Caldera remarkable symmetric, and incredibly well preserved — there were no major eruptions after the last collapse a million years ago to obscure the valley, resurgent domes and ring fractures that were formed during that collapse.  These qualities attracted geologists from around the world, and it has become the archetype volcanic caldera referenced in hundreds of studies and textbooks.  Although the Jemez Mountains were recognize being volcanic by the later part of the 19th century, it was not until the 1920s when C.S. Ross of the USGS visited, and later teamed with R.L. Smith in 1946 that the area was mapped in detail.  This mapping was done in part to understand the potential for supplying the new Los Alamos Scientific Laboratory with fresh water, and whether it was possible to bring a large natural gas line across the Valles to provide energy for my home town.  In 1970 Smith, Bailey and Ross published a beautiful geologic map of the Jemez Mountains and the Valles Caldera (figure below), and was the first map to grace the wall of my bedroom (I wish I could find that original wall hanging, but alas, it was packed away when I left for college and no doubt is today been composted and returned to the soil…).

jemez.htm_txt_smithmapjemez2

A section of the Smith, Bailey and Ross map (1970) showing the geology of the Valles Caldera. The yellow domes circling Redondo Peak (the brown color in the center of the figure) are the post collapse rhyolite resurgent domes.  The olive green color is the Bandelier Tuff – the base rock beneath Los Alamos.

The colors of the map hint at the extraordinary history of the Jemez Mountain Volcanic Field (JMVF).  The exact reason that the JMVF exists remains a bit of a mystery; it is located at the intersection of the western margin of the Rio Grande Rift and a trend of volcanic fields called the Jemez Lineament that has been postulated as a ancient “zone of weakness” that allows magma generated in the mantle to rise up into the crust.  I think that it is far more likely that the Jemez Lineament is the lucky connection of dots on a map, and that a more plausible explanation is that marks the boundary between a thick and stable crust (the Colorado Plateau) and thinner, more tectonically active crust.  Irregardless, it is clear that the opening of the Rio Grande rift caused volcanic activity to began about 13 million years ago in the vicinity of present day Los Alamos.  For about 10 million years the volcanism was dominated by basaltic lava flows.  Black Mesa, near Espanola, is one of the most famous landmarks representing this period of volcanism (Black Mesa is about 3.7 million years old).  About 3 million years ago eruption of more silica rich magmas commenced and the Jemez Mountain began to grow — there were probably 6 to 10 major volcanoes that tapped interconnected magma bodies.  These volcanoes conspired to create a major eruption about 1.5 million years ago that erupted what is known as the Otowi Member of the Bandelier Tuff.  Nearly 450 cubic kilometers of ash was erupted over a short period (probably a few years, but certainly less than a few decades).  This resulted in a collapse of the volcanic system, and the creation of the Valle Toledo Caldera.  This caldera is obscured by a similar sized eruption about 1.2 million years ago that ejected about 350 cubic kilometers of ash, the Tshirege Member of the Bandelier Tuff.  On the eastern margin of the Valle Toledo is the highest peak in the Jemez, Tschicoma Peak (elevation 11,561′), an remnant that survived both collapses.  The second eruption, and subsequent collapse created the now familiar Valles Caldera.

ashfall

Extent of ash fall from the second major Jemez Mountains Volcanic field eruption (1.2 million years ago). Ash has been identified in Kansas and Wyoming, and a large volume of the ash was transported down the Rio Grande (the blue streak in the map down the center of New Mexico).

The widely popular phrase “super volcano” has its roots in the 20th century, but mostly it is a phrase invented by the media around 2002 to dramatize the power of big volcanoes.  By 2003 the phrase appeared in more than 100 stories that covered everything from global warming and cooling to mass extinctions.  The USGS tied the phrase to the Volcano Explosivity Index (VEI), a measure of “explosiveness of eruptions”, and a VEI value of 8 became the definition of a super volcano, and implies a volume of material erupted that is at least 250 cubic km.  There have been 3 super volcanic eruptions in the US in the last 1.2 million years; the Jemez, Long Valley, California and Yellowstone in Montana/Wyoming.  All three of these eruptions resulted in the creation of a caldera.  Of course, our human centric view of geologic time — i.e, a million years is a long time — distorts the sense of “super” volcanic eruptions. Although Yellowstone was a large eruption, it was dwarfed by an eruption 28 million years ago that created the La Garita Caldera near Creede, Colorado.  Over the same time that it took the Jemez to erupt the Tshirege tuff, the La Garita erupted the Fish Canyon Tuff — all 5,000 cubic km of it (more than 15 times larger!).  Despite the size of La Garita,  Los Alamos is perched on the shoulder of a real super volcano.

VCC.copy

Comparisons of volumes of eruptions – Yellowstone and the Valles are “super volcanoes”, while more recent eruptions like Crater Lake and Krakatau have to settle for being “big” and Mt. St. Helens is just puny.

The relative tranquility of the Valles Caldera belies its violent history and magnificent history.  The most recent significant volcanic activity in the Jemez is the Banco Bonito rhyolite flow, which is located smack dab in the middle of the Jemez Caldera marathon.  The Banco Bonito is a very silica-rich rhyolite, and filled with large blocks of obsidian.  Although most everyone recognizes obsidian, and thinks arrowheads and black shiny pebbles, the geologist thinks about very rapid cooling of a volcanic rock.  Obsidian is silica glass – same material as a chunk of quartz, but it has no crystalline structure due to the rapid quenching of the hot lava. The Banco Bonito rhyolite was extruded (probably not erupted) 40,000 years ago.  Although the Jemez Mountain Volcanic Field will be active again in the future, it is mainly showing signs of exhaustion, and the likelihood of a future, large scale eruption is extremely small. Running through the Valles Caldera on a marathon is a unique experience.  Laid out along the course is every aspect of a few million years of violent tectonic history.  Ash fall, resurgent domes, ancient lake beds that filled with water in cooler and wetter times.

Vallesroute

A view from the southeast to the northwest across the Valle Grande, Redondo Peak, the the Colorado Plateau on the horizon. A little over 1/2 of the marathon course is an out-and-back from El Cajete to Cerro Pinon – right through the heart of the Valles Caldera. Also shown is the head of Bland Canyon, home of the ghost town. Picture from 2011 Nature article on Southwest drought.

The Valles Caldera Marathon

The Valles Caldera runs – there is a marathon, half marathon, and a 10 km – are not classic trail runs per se.  Most of the courses utilize dirt roads that once were used to move cattle or cut timber, and only some short segments are single track.  However, this does not diminish the spectacular setting of the race. It does mean that most people run the distances much faster than a typical trail run (I say “most” because single track versus tire rutted roads has nearly zero impact on my speed – sadly).  The races start at Banco Bonito Staging Area within Valles Caldera National Preserve.  The name “Banco Bonito” is applied to a modest plateau that is composed of the rhyolite-obsidian conglomerate that goes by the same name.  It is easy to find very attractive pieces of obsidian at the starting line — just look down.  There are more than 300 people signed up for the half marathon and 10k, but only about 45 of us toe the line for the full marathon at 7:30 in the morning.

start

Gathering of the runners for the start of the Valles Caldera marathon. Temperature at the start was 34 degrees, and throughout the day the weather alternated between sun, clouds and occasional grapple. Perfect.

The course for the marathon heads due east, climbing up the Banco Bonito lava flow along a logging road.  The lava flow is probably not obvious to most of the runners as it now is forested, and only along certain sections are there stratigraphic sections exposed.  But the topography of the lava flow is evident;  over the first three miles we climb about 450 feet (not much elevation gain, but enough to slow old runners down).  The pack of runners sorts out pretty rapidly, and good runners like Dave Coblentz disappear with a doppler shift over the horizon.  At the three mile mark the course comes to an aid station on the edge of a large bowl shaped depression — El Cajete.  This is a very significant geologic formation (but not such a significant aid station).  El Cajete is the crater that last had significant volcanic activity in the Valles Caldera.  It is responsible for the Banco Bonito lava flow 40,000 years ago, as well as a massive eruption of pumice sometime after the lava flow.  The pumice fell close to the El Cajete, and dammed the Jemez river creating a lake in the Valle Grande.

Cajete.elk

Aid station at mile 3 – looking out on El Cajete. If you click to enlarge the photo you can see a herd of elk scurrying across the crater on the right hand side — the crater is big, so the elk look small.

From El Cajete the course drops off the plateau and the run is downhill for 2 miles.  Fast and easy.  Unfortunately, the elevation lost is a penalty for the next part of the race.  At mile five there is a steep climb up a pass between Redondo Peak and another resurgent dome called South Mountain.  In a little bit more than a mile we climb 550 feet to the high point of the race, 9150′.  The top of the pass is a reward, but also a harbinger of things to come since we have to repeat this climb on the return from the Valle Grande.

profile

Course elevation profile. By my watch the course of 25.8 miles long.

From mile 6 to mile 12 the course is in the Valle Grande – well, strictly speaking, skirting around the edge of the Valle.  The grass “meadow” of the Valle Grande is due to the fact that it was a reoccurring lake bed in the last million years, and it is not particularly friendly nutrition wise to trees.  The last time the lake had a significant extent was after the El Cajete pumice eruption, and probably lasted for 4 to 7 thousand years (there have been smaller lakes during damp cool periods usually associated with glacial epochs).  The picture below is a view across the Valle towards Pajarito Mountain.  That summit, all 10,400 feet of it, is the high point of the Jemez Mountain Trail Runs — which will be run a month from now.

ValleGrande

A view across the Valle Grande to Pajarito Mountain. The weather alternated between sun and dark clouds through the entire run. The temperature was mostly in the high 40s, perfect for running a marathon.

Running through the Valle is always wonderful.  It is sensational scenery, and mostly flat topography.  At mile 9.4 I get passed by the leader of the pack returning towards the finish.  This means that the leader is about 4 miles ahead of me already.  Once the first runner passes by me it is a steady stream;  strangely, all the runners that are ahead of me look like they are strong and running very easily.  I, on the other hand, am beginning to lose focus and daydreaming of the geology.  Dave Coblentz passes me with a group of 5 or 6 runners at mile 9.7. The course “turns around” is at a point just beyond another resurgent dome — Cerro Pinon.  The milage here is just about 12 miles; there is a mental boost knowing that the “out and back” is done, but I also realize that there are 14 miles to go.  For the next 5 miles I pass by a few runners (a very few) that are slower than me, but mostly see no one.  I am alone – happy, but alone.  The climb back up the pass at South Mountain is brutal, but once that is done I am certain that I will finish the race largely unscathed.  The run down from South Mountain is fast, but as I expected, hard on my legs. The run between miles 18 and 22 is a descent of nearly 800 feet.  It should be fast, but my legs are tired.  There is a great aid station at mile 19, and I stop for way too long to eat oreo cookies.  The descent ends at a broad meadow called Redondo Meadow.  This meadow is an wildlife experiential station, and there are lots of people working in the area.  The course route is always confusing here because there is no real trail across the meadow, and there are meandering streams.  The course is marked, but that means you actually have to pay attention to the flagging (not my best skill – however, I have memorized the maps, so I don’t get detoured).  Once across the meadow the home stretch begins.  A steep climb up the Banco Bonito lava flow, and then a lonely run back to the finish.  I pass a couple of slowest runners of the 1/2 marathon, and try to encourage them (however, they are really tired).

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Crossing the finish line – photo curtesy of Petra Pirc. I finish in a little over 5 1/2 hours. Long after the good runners, but happy for the experience.

I rambled into the finish line in a little over 5 1/2 hours.  It is a nice marathon – not exactly a trail run, but much harder than a street run.  The total elevation gain is about 3000 feet and the average elevation along the course is 8400′.  However, it is the geology that makes this run so great.  The Valles Caldera is truly a marvel….

101 spinel twins: symmetry and beauty in silver

The universe is built on a plan the profound symmetry of which is somehow present in the inner structure of our intellect, Paul Valery, 19th century French Poet

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Silver, Kearsarge Mine, Houghton Co., Michigan. The specimen is 3.5 cm across. This native silver is a lustrous example of a “weave” of sliver crystals exhibiting spinel twinning. Photograph by Jeff Scovil. Click on any photo in the article to get a larger view.

When I first started building a mineral collection — back about 1960 — the single most compelling criteria for determining if a specimen was a “keeper” or just something for the beer flats filled with colorful, yet, unworthy rocks, was whether there was a euhedral crystal.  My fascination with the perfection of a sharp crystal face is not at all uncommon for beginning collectors.  The fact that nature could take time to construct something so perfect strikes a deep chord; the vast universe created by the ultimate act of violence – the big bang – and ruled by entropy, and inevitable decay, still values symmetry.  I recall an early discussion with my mother on the beauty of spring flowers – I asked her why she thought they were beautiful, and she responded with a joyful exposition on the bright and varied colors and the delicate nature of the pistil, and remarkable symmetry of the petals.  I told her that the petals were exactly like crystals since they are always alike, and must be following some sort of “rules”.

The English word symmetry comes from the Greek symmetria;  in turn, symmetria is a concatenation of  Greek words sun and metron, meaning “together” and “measure”. There is a substantial body of Greek literature that refers to symmetry as  “harmonious and beautiful proportion and balance”.  This philosophical definition of symmetry deviates from the strictly mathematical definition, but still projects the power of something that is predictable and has a geometric balance to be pleasing to the eye.  This “pleasing to the eye” is a euphemism for beauty — hard to define exactly, but beauty excites our aesthetic senses.

To me, there is nothing more pleasing to the eye than a silver specimen exhibiting spinel twinning – repeating patterns of crystals that produces a highly geometric weave.  The photograph at the top of the column is a silver from the Kearsarge Mine, Houghton Co., in the Upper Peninsula of Michigan. The specimen is defined by a central rib — an elongated stack of silver octahedrons, and branches intersecting the this rib at angles of approximately 60 degrees.  In turn, these branches have secondary branches exiting at similar angles.  The repeating geometry yields a specimen architecture that is clean and sharp – an exemplar of what the Greeks meant by symmetry.

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Silver, from a locality near Tongchong, Yunnan Province, China. Specimen height is 6cm. The wires are the result of decomposition of acanthite.  Jeff Scovil photograph.

Silver:  a special element

Silver is a remarkable element that can form an array of minerals; about 180 different species.  Thankfully, elemental silver is sufficiently inert to occur in nature and is widely distributed throughout the world.  Native silver is a metal of bright white color; it has the highest reflectivity of any metal.  Silver is also the best metallic conductor of heat and electricity and extremely malleable and ductile. These properties are, of course, a result of crystal and atomic structure, which is a face-centered cube with metallic bonds.  The atomic radius of silver is nearly identical to that of gold – and gold commonly substitutes into the silver crystal lattice.

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Native silver crystal forms, from Goldschmidt (1913). The octahedron is most common, although cubes are much coveted by collectors. The bottom 3 figures show spinel twinning.

Silver crystallizes in the isometric system, and although individual, sharp macro crystals are rare, the octahedron and cube forms are most common.  The largest individual crystals are from Kongsberg, Norway, where some octahedrons 3-5 cm on a side grace a few fortunate collections.

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Cubic silver in calcite; Kongsberg, Norway.Each of the large cubes are approximately 1 cm on a side.  Jeff Scovil photograph.

As a rule, crystals of silver are equi-dimensional or platy. The platy nature comes from the propensity from silver to twin (this is similarly seen in gold and copper) on octahedral faces {111}.  This twinning is known as spinel twinning and is described below.  The conditions for when spinel twinning occurs appears limited – although silver masses of spinel twins are known from hundreds of locations, there are only three or four localities where this type of silver crystallization is common.  The two most famous localities are Batopilas, Mexico and Chanarcillo, Chile.

By far, the most common form of silver in a mineral collections is the wire – which is a secondary growth from the decomposition of silver sulfides and sulfosalts. Any silver deposit that undergoes supergene enrichment inevitably has silver wire specimens.  The picture at the top of this section of the article is a fine silver wire mass from Tongchong in China.  The wires in this specimen are attached to a very small piece of acanthite, no doubt the host material that provided the silver.  All silver sulfides and most silver sulfosalts will produce silver wire upon disassociation — especially promoted by heating.  Although wires can be extremely interesting and coveted specimens for collectors, there are been numerous cases where the wires were “grown” by unscrupulous collector/dealers and passed off as “natural” specimens.

Beauty in Nature

When I hear the word “beautiful” used to describe minerals by collectors I often ask what they mean.  More often than not, the answers seem wanting to me.  Mostly, it is about color — pink and red minerals are always “beautiful”, but black and brown minerals are “interesting”.  Although color can transfix, and certainly evoke emotion, I can not relate to it as the primary metric of natural beauty.  I am also looking for structure in my surroundings – a window into the soul of nature, order out of the chaos all around me.

A seminal event for me was attending “math summer camp” during the summer between 7th and 8th grade.  The instructor was an outstanding teacher named Jack Gehre, and his focus was geometry and trigonometry. Early in the class Mr. Gehre introduced Euler’s formula; for any normal polyhedron, the sum of the number of faces plus the number of vertices, minus the number of edges always equals 2.  I spent the rest of the summer camp trying to understand why.  I suddenly had a “rule” in nature that I could apply to my mineral collection — a rule mysterious and powerful, but incredibly simple.  It was beautiful.  I did not know much about Euler then, but later in college I was introduced to another “law” by Leonhard Euler — an incredible 18th century Swiss mathematician — that has to be the most beautiful equation in all of nature.  I was in a class on series analysis, and the professor, Alan Sharples, walked in the first day of the semester and wrote the following on the black board:

theidentity

Sharples said, “this is Euler’s identity, a remarkable assertion.  Prove it.  That is all for this first day of class.”  Turns out that this is pretty easy to prove, but when I viewed this on the blackboard I was transfixed — it was pure beauty.  Imagine three essential mathematical constants – e, pi, and  – combined to equal -1.  Wow – simple, brief, and exact.  To this day I view this as a definition of beauty (Euler’s identity is routinely identified as the one of the most beautiful equations in science).

Euler’s identify may seem a long ways from realm of beauty in the mineral kingdom.  However, to me, they are very much related.  Simple, surprising, and an expression of natural symmetry.

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Herringbone silver mass, Batopilas, Chihuahua, Mexico. The Specimen is 3.75 cm across. Jeff Scovil, photograph.

Respect the Spinel Twin

Crystal growth in nature is quite complex; the crystal form, crystal size, crystal chemistry all are expressions of the paragenesis. Crystallization for most geologic materials involves the precipitation of a solid (the crystal) out of a solution or solvent (usually hot thermal fluids, although solutions of nearly any temperature can carry dissolved loads of ions and cations).  Crystals start with nucleation of a few molecules from the solution, and then growth occurs by pulling the necessary ionic components out of solution.  The rate at which individual crystals grows depends strongly on the saturation level of the ions of interest – supersaturated solutions appear to be able to grow crystals at extraordinary rates (at least compared to geologic time!), sometimes at several cubic cm per hour.

It is not clear who first recognized twinning in crystals, but it was first written about in detail by Rene-Just Haüy in his epic tome Traité de Minéralogie, published in 1801. In the beginning part of the 20th century there were a number of studies to understanding twinning in minerals. The classic definition was introduced by Friedel in 1926: A twin is a complex crystalline edifice built up of two or more homogeneous portions of the same crystal species in contact (juxtaposition) and orientated with respect to each other according to well-defined laws. The “well-defined laws” all are based on some simple ideas, the most important of which is that within a crystal core that a least one lattice row (i.e., a crystal edge) is common to two different crystals. The figures below illustrate this concept — the lattice of a cubic crystal is defined by four points, and a plane can be drawn through these points that allows a second crystal to share lattice points but have a rotated orientation. Twinning adds symmetry to a crystal aggregate, most commonly about a rotation axis or reflection across a plane. In the metals copper, gold and silver, a particular type of twin is common, called the spinel twin.

twinning planespineltwin2

Spinel twins are so-named because it is a very common habit seen in the mineral spinel. They are contact twins, meaning that have a planar composition surface shared by two individual crystals; this surface is along an octahedral face (written as {111}), and means that there is a rotation of 180o about the contact plane. This is illustrated by the lower figure above – there are two octahedrons joined along a contact plane, but the top terminations “point” in directions and are separated by 120o. The figure below shows how spinel twins can be flattened, and give the characteristic triangular faces that are seen on platy crystals of silver (and gold).

triangularface

Notional relationship between an octahedron and a spinel twin producing a triangular type crystal face. This is “notional” in that this is NOT how the spinel twin evolves with time, but rather, a visual guide to compare an octahedron (left) and triangular face (right).

In silver, spinel twinning almost always repeats itself with regularity, producing a pattern that resembles a weave of wires.  The silver at the top of this section of the article is from Batopilas, Chihuahua, Mexico, and is an example of a mass of spinel twins.  Through the middle of the specimen is a series of parallel elongated crystals, and growing “off” these strands are regular strands oriented at 60 degrees (or 120 degrees, strictly speaking). These are all spinel twins – repeating some natural frequency that is due to a long lost geologic condition.  Once assembled, the spinel twins from an aggregate of crystals that has been called a “herringbone” silver in reference to the similarity to the shape of the rib cage of the smelly game fish beloved by the peoples of the Baltic.

Why do spinel twins form in silver?  Under certain ideal conditions, a single large crystal represents a “minimum” energy condition, and thus is due to an important thermodynamic rule — a chemical system will stabilize at state of least energy.  If individual crystals are a minimum energy state, then twinned crystals are by necessity at state of higher energy, and thus should be rare. However, environmental conditions tend to localize energy states; for a supersaturated solution, the crystal growth is extremely rapid, and twinned crystal allow more ions to join a crystallize aggregate faster, thus minimizing a local energy state.  For all “herringbone” silver specimens it appears that the conditions of formation require a supersaturated solution, low in concentrations of sulfur, and extremely rapid crystal growth.  These conditions are relatively rare in most epithermal vein deposits; it is very uncommon to find a spinel twinned silver specimen from the great silver deposits of Colorado, Ontario or Freiberg!

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Large silver plate (7.5 cm from side-to-side) from Chanarcillo, Chile. The specimen is a weave of spinel twins – and is my favorite silver specimen in my collection. Jeff Scovil photograph.

The silver pictured above is my favorite native silver in my entire mineral collection.  This is a large “herringbone” plate with a three dimensional repeating pattern of twins.  The specimen represents something remarkable in turns of crystal growth.  The tiniest variations in chemistry or temperature during growth would have truncated the growth of this silver weave.

spineltwin.closeup

Close up of the Chanarcillo specimen shown above. The central rib is an elongated chain of octahedrons. Field of view is 3 cm. Repeatedly, silver crystal “twin” off the octahedral face(s). At the very top of the specimen there are identifiable octahedrons.

A close examination of the Chanarcillo herringbone yields views of spectacular detail – endlessly repeating, and shouting the fundamental rules for symmetry in crystals. Along the edges of the crystalline mass you can see individual octahedrons – the termination of various elongated crystals.

Beauty and the pretenders

Rapid growth in silver often produces crystalline masses that are complex.  However, spinel twins are distinct, and uncommon.  Rapid growth often leads to dendritic masses – mostly silver feather patterns or strings of stacked cubes. These dendrites are not spinel twins; in fact, instead of fundamental order, they represent chaotic growth.  Although there is some sense of beauty in the randomness of dendrites, it is mostly through “self-similarity” – various patterns that appear to scale with size.  This is fundamentally different than ordered spinel twins – and in many ways points to disordered processes.  I am always shocked (okay, probably an overly harsh expression of emotion) when I find dealers selling “herringbone” silvers that are in fact dendrites.  That is like marketing hamburger as Filet Mignon.  Similarly, silver wires can certainly be attractive; however, they are products of mineral destruction not construction.  To me, beauty in silver spinel twins is about construction, order, and symmetry.  Defining beauty will allows be in the eye of the beholder — it is just better when there are rules involved.

Climbing the Great White Whale: Mt. Rainier and marveling plate tectonics

Each volcano is an independent machine—nay, each vent and monticule is for the time being engaged in its own peculiar business, cooking as it were its special dish, which in due time is to be separately served – Clarence Dutton, American Pioneering Geologist, 1880.

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Mt. Rainier, the great white mountain (for me, the great white whale!). This photo was taken on Sept. 9, as I flew into Seattle to begin my journey to the summit. The photo is from the east/north, and you can see the summit crater on the top left flank of the mountain. The clouds are at about 6500 feet elevation.

Mt. Rainier is the most iconic mountain in the contiguous United States. Its nearly perfect conic shape rising 14,410 feet above sea level, and located only 35 miles from Tacoma and Puget Sound make it the most prominent geologic structure in the country; the white cap of the summit plays a game of hide-and-seek with the major metropolitan sprawl of Seattle-Tacoma and when the clouds rise even the most jaded Emerald City resident is jarred by its majesty. I have long wanted to climb Rainier, but never found the opportunity in my youth or the time in my middle age. However, my wife surprised me with a gift on our 25th anniversary in 2013 – the opportunity to climb the great white whale. Work commitments still made the scheduling of the climb non-trivial, but finally in September of 2014 I had the chance to join an organized expedition.

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Mt Rainier from an airplane flight (SEA-DFW) I took in the summer of 2013. The clouds cover the summit, which has a topographic prominence of over 13,200 ft. There are 26 alpine glaciers on Rainier which gives it its perennial white appearance.

Rainier has a special place in the minds of geologists – it is a magnificant monument to the violence of plate tectonics. The Cascade Mountain Range stretches from Mt Garibaldi located just north of the Canadian-American border to the Lassen Peak in northern California. Along the 700 mile arc of the Cascade Mountains there are at least 20 young volcanic peaks – Rainier is the highest today, although the nature of stratovolcanoes is that Rainier will eventually follow the example of Mt. St. Helens and “blow its top”. In the 1960s it was recognized that the Cascades where the volcanic signature of a subduction zone – the collision between the Juan de Fuca oceanic plate to the west and the North American continental plate to the east. I was a graduate student at Caltech in the late 1970s, and understanding the nature of subduction was a subject of intense research. In addition to stratovolcanoes, subduction zones are the source of most of the largest earthquakes observed on the planet. Understanding why some subduction zones had mega earthquakes – events with magnitudes that exceed 9.0 – while others only had earthquakes with a maximum magnitude of 8 or 7 was a mystery. In the Seismolab at Caltech there was a daily coffee in which the faculty and other graduate students discussed the most recent seismicity and new areas of research. It was in these “coffees” that a generation of seismologists were created – everyone was expected to contribute to the discussion and debate, and very foundations of modern seismology were laid. Hiroo Kanamori, perhaps the greatest observational seismologist in history, was pondering the “why some subduction zones have mega earthquakes” question and working with  several of my peers developed the rationale for mega thrusts based on the concept of “coupling” between the subducting plates. This spawned the concept of “comparative subductology” which is rooted in Scottish geologist James Hutton’s concept of uniformatarism – if it is happening now, then it happened in the past, and will happen in the future. One of the surprises of the comparisons of subduction zones world-wide was that Cascadia looked a lot like the segments of the Chilean and Aleutian subduction zones that generated mega earthquakes in 1960 and 1964. However, Cascadian was pretty quiet seismically, so there was a general skepticism in the geologic community that Seattle would some day have an earthquake that would dwarf anything that could happen in California. Today the discussion is not about size of a future earthquake in Cascadia, but rather when and how often.

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Caltech 1980 — I am one of the leaders of a field trip to Owens Valley (I am the guy at the far left with the clip board and the really strange ball cap) after the Mammoth Lakes earthquake sequence. The earthquakes occurred within a week of the eruption of Mt. St. Helens, leading many to suggest a link. The Seismolab was home to an amazing cadre of faculty and graduate students in the 70s and 80s that help define the paradigm of modern plate tectonics — including the understanding of the Cascadia subduction zone.

My own research at Caltech was more focused on computational methods for seismology and understanding the seismograms from nuclear explosions – however,  I was captivated by the discussions of mega-thrusts. In May 1980 Mt St. Helens erupted – and the reality of the restlessness of Cascadia hit home. I very much wanted to climb Mt. Rainier right then. However, it took nearly 35 years before the opportunity would arise. Of course, this is a geologic blink (or wink!) of an eye, and the decades had not diminished my enthusiasm to walk on the volcano.

overhead.rainier

Google Earth image of the Cascades. The white dot in the middle is Mt. Rainier. To the south (to the left in the image) are Mt. Adams and Mt. Hood. This line of high peaks are stratovolcanoes above the subducting Juan de Fuca oceanic plate. The high mountains of the Cascades blocks the oceanic moisture and makes the Pacific Northwest coastal region a rain forest — and a relatively dry desert in eastern Washington and Oregon.

A brief history of Mt. Rainier (apologies to Stephan Hawking)

Most discussions that start with the topic of “history of Mt. Rainier” focus on it relatively modest relationship between the mountain and man. The earliest evidence of human occupation of the Pacific Northwest is about 13,000 years before the present, and it is certain that the mystic vision of the rugged, glacier -covered tower of andesite evoked the same since of wonder that it does today.

The first written records associated with Mt. Rainier are from the annals of Captain George Vancouver who was the commander of the English vessel Discovery that was sent to explore the Pacific Northwest. In May of 1792 the Discovery sailed into Puget Sound, and Vancouver saw the snow covered volcanoes of the Cascades, and noted three (Mt. Baker, Hood and Rainier) stood out “Like giants stand To sentinel enchanted land”. On May 8, Vancouver wrote “the round snowy mountain, now forming its southern extremity, and which, after my friend Rear Admiral Rainier, I distinguished by the name of Mount Rainier”.

Cascade_Eruption_2008v

The eruptive history of the Cascade volcanoes (figure from the Pacific Northwest Seismic Network) over the last 4000 years. Mt. Rainier is the largest of volcanoes, but it the last few thousand years it has been less active than Mt. St. Helens.

The eruption history of the Cascades – about 50 eruptions in the last millennium – doubtlessly meant that the indigenous peoples knew that the Cascade peaks were volcanoes. However, this first recorded suggestion that Rainier was volcanic was noted in the diary of William Fraser Tolmie in 1833. Tolmie was a remarkable naturalist from Scotland that was trained as a physician at Glasgow University, and joined the Hudson’s Bay Company in 1832. Upon arrive in Puget Sound one of the first tasks he undertook was to visit Rainier on a “botanizing excursion”. In is notes he wrote that the rocks of Rainier were “volcanic”. I don’t know what character of the rocks lead him to that conclusion, but Tolmie set the stage for USGS studies 40 years later that would confirm that Rainier was a composite volcano. As a side note, Dr. Tolmie as also the first person to write about an earthquake in Cascadia when a small tremor struck Puget Sound on June 29, 1833.

Mt. Rainier attracted many attempts to scale its heights, but the first documented successful ascent occurred by the son of the first governor of the Washington Territory and a pioneering mountaineer in 1870. General Hazard Stevens (a well-named military man, especially climbing Mt. Rainier) first came to the Puget Sound area with his father in 1854 and resolved to climb the “great white mountain”. After a military career and the end of the Civil War, Stevens returned to Washington Territory, and teamed with Philemon Beecher Van Trump in August 1870 to climb Rainier. Stevens wrote an account of their journey – which was quite harrowing – that was published in Atlantic Monthly in 1876. Stevens wrote “We had spent eleven hours of unremitted toil in making the ascent, and, thoroughly fatigued, and chilled by the cold, bitter gale, we saw ourselves obliged to pass the night on the summit without shelter or food, except our meagre lunch. It would have been impossible to descend the mountain before nightfall, and sure destruction to attempt it in darkness… Climbing over a rocky ridge which crowns the summit, we found ourselves within a circular crater two hundred yards in diameter, filled with a solid bed of snow, and inclosed with a rim of rocks projecting above the snow all around. As we were crossing the crater on the snow, Van Trump detected the odor of sulphur, and the next instant numerous jets of steam and smoke were observed issuing from the crevices of the rocks which formed the rim on the northern side. Never was a discovery more welcome!” Today we recognize that they had found fumarole activity, a reminder that silhouette of Rainier is only temporary.

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The Muir party summiting Mt. Rainier in 1888.

P.B. Van Trump would visit the summit 5 more times including guiding John Muir in 1888.  Muir had to be convinced to undertake the climb, but once at the top he stated “I hardly know whether I had better try to describe the view but will say that for the first time I could see that the world was round, and I was up on a very high place. The air was very light…I stood there all alone, everything below and all so grand. I had never before had such a feeling of littleness as when I stood there and I would have stood there drinking in that grand sight, but they wanted to go so we started down”.

By the 1930s geologists had begun to unravel the complex volcanic history of Mt. Rainier. The present conically shaped mountain is quite young – less than 600,000 years old. Beneath the high reaches of the mountain though are a complex series of mostly volcanic rocks that record ancient geologic environment and long extinct versions of Mt. Rainier.  The most prominent basement rock is the granodiorite of the Tatoosh Pluton (there are a range of ages for the pluton which probably reflects a complex history – it cooled between 25 and 12 million years before present) which was the crustal magma chamber of former stratovolcanoes.

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A geologic cross-section through Mt. Rainier from Crandall (1969). The modern andesite and mudflows that define Rainier today lie above a large granodiorite batholith that is approximately 25 million years old.

Mt. Rainier birth as a stratovolcano probably occurred about 850,000 years before the present, and the bulk of the present conical shape is about a half of a million years old. The present summit has two craters that reflect recent eruptions.  It is clear that in the past the summit of Rainier was somewhat higher — maybe reaching 16,000 feet elevation — but explosive eruptions have removed the older cap rock.

Although the nature of the Cascades and Mt Rainier were understood by the 1960s, it took the articulation of theory of plate tectonics to set the framework for why the stratovolcanoes exist. The North American plate, dominated by a large continental mass has interacted with an adjacent oceanic plate, known as the Farallon Plate, since Jurassic time (more than 150 million years before the present). Eventually most of the Farallon plate was subducted beneath North America, but a fragment remains off the coast of Washington, Oregon and northern most California. This fragment is known as the Juan de Fuca plate, and is being subducted at a rate of about 4 cm/yr.  In addition that subducted oceanic crust is young – about 10 million years old.  The USGS figure below shows a notional cross section beneath Washington.

subduction

The Cascade volcanoes are a direct product of the subduction of the oceanic crust of the Juan de Fuca Plate.  As the plate descends beneath North America the minerals within the plate release water due to increasing pressures and temperature in the mantle.  This water has the effect of promoting melting of mantle rocks in North American kneel above the sub ducting plate.  The melt rises, and eventually creates magma bodies in the lower crust, which in turn occasionally erupt in volcanoes at the surface.  Once a pathway for the magma to rise to the surface is established a stratovolcano grows. A science paper that was published this year (2014) provided an image of the mantle and crustal rocks beneath Mt. Rainier.

RainierElectricView

Electrical resistivity in the Earth for a cross section beneath Mt. Rainier (the location is shown with a triangle).

The electrical resistivity of rocks is highly dependent on a couple of things;  temperature, water content, and mineral content.  In the figure you can see the cold oceanic crust of the Juan de Fuca plate descending (the blue streak on the left side of the figure).  At about 50 km depth pressures are reached that cause a “de-watering” of the plate, which in turn, promotes the mantle melting.  This is the red and yellow colors beneath Mt. Rainier. The dark red blob to the left of Rainier is likely it’s magma chamber, located between 5 and 10 km below the surface.

Although the volcanoes of Cascadia are not at all unexpected, seismologists did not understand why earthquakes seemed so infrequent in Washington.  Most subduction zones would have a much higher rate of seismicity that was observed here  — and this was the topic of discussion at Caltech in the late 1970s.  Kanamori and graduate student Larry Ruff looked at subduction zones worldwide and plotted the size of the maximum observed earthquake as a function of the age of subducting plate and the rate at which the subduction was taking place.  The analysis showed that rapid subduction of young oceanic plates resulted in very large earthquakes — mega thrusts.

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Size of maximum observed earthquake as a function of rate of subduction and age of plate being subducted (from Ruff and Kanamori, 1980).

Tom Heaton and Kanamori used this “comparative subductology” and other geophysical constraints to postulate that the Cascadia subduction zone was capable of generating a mega-thrust earthquake — as large as magnitude 9.0 (paper appeared in 1984). The paper was meet with a great deal of skepticism because the seismicity along the Oregon-Washington coast was quite moderate.  However, in 1987 Brian Atwater, a USGS geologist, found evidence of a major tsunami inland from the coast.  Finally, Japanese seismologists had long been perplexed by a tsunami that hit the coast of Japan in 1700 but did not appear to be connected to any Japanese earthquake.  Connecting the dots, seismologists were able to show that the 1700 Japanese tsunami was most likely created by an earthquake with a magnitude between 8 3/4 and 9 1/4 in Cascadia.

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A trench through a coastal deposit in Oregon shows the sands brought ashore by the 1700 tsunami (Atwater et al., 1999).

Today there remains debate about the repeat frequency and size  expected for the Cascadia earthquake, but it is now excepted that it is only a matter of time before it strikes.  Mt Rainier seems like an ancient and noble giant benignly guarding Puget Sound. In fact, it is a very ephemeral geologic feature that will disappear in a few hundred thousand years, and most certainly will do violence to the equally temporary residents of the Pacific Northwest.  Surely this makes climbing Rainier most interesting for a geoscientist!

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Mt. Rainier from Paradise Ranger Station. This is the start of the IMG hike up the mountain – elevation of Paradise is at an elevation of 5200 ft, snow line is 7000 ft, and the top is 14,411 feet.

The expedition

The National Park Service keeps track of the number of people that attempt to climb Mt. Rainier and those that actually make the summit.  The numbers are a little surprising;  a little more than 10,000 attempt the ascent annually, and about half actually make it tothe top.  This statistic is pretty robust for the last 25 years, and clearly establishes Mt. Rainier as a signifiant challenge.  It is difficult to obtain quality data on the reasons that the success rate is so low, but the two most common anecdotes are weather and altitude maladies.  The weather is easy to understand – the strong oceanic flow from the Pacific brings significant moisture inland to the mountain. When the flow encounters the mountain it is forced to flow over the elevation – which cools the air, which in turn forcing out the moisture, building clouds, and raining/snowing. The jump off for my expedition is the Paradise Ranger Station (elevation 5,200 feet), which has an annual rainfall of 126 inches. That is twice as much precipitation that is received at Ashford (elevation 1,760 feet) the home to International Mountain Guides, my chosen expedition team. Ashford is only a few miles west of Paradise, but the difference in rainfall illustrates the rapid change in weather and how the steep topography of Rainier controls its environment.

The challenge of the weather, and the fact that a significant stretch of the ascent is on ice are the reason that I chose to join an expedition rather that trying to cajole a few friends (whom are all as old as I am) to take a week off work and avoid ice crevices.  I was not particularly worried about the physical part of the climb – running ultra trail races is more demanding – but I last climbed alpine glaciers more than 25 years ago, and as Shakespeare said “The better part of Valour, is Discretion”.  There are three well regarded companies that provide a suite of guided expeditions up Mt. Rainier.  I choose International Mountain Guides (IMG) for my adventure based on the rave review of a friend.  I was a little nervous about joining a group expedition – in general, I am not a group kind of guy – but my friend assumed me that this was a great experience, and in fact, he was correct!

On Wednesday afternoon (Sept. 10) the 8 climbers in my expedition checked in with IMG in the small town of Ashford which is situated on the Nisqually River.  The Nisqually is the main drainage of the southern half of Mt. Rainier, and I spent a couple of hours before checking in at IMG facility hiking along the river, and there are some spectacular exposures of the Paradise Lahar cut by the river channel.  The age of the Paradise Lahar is probably about 7,500 years before the present, and the thickness exposed near Ashford is at least 100 feet — it must have been a significant and destructive event.  The purpose of checkin is to assure that all the hikers are ready (so there is a very long equipment check), make introductions, and set expectations.  The climbers in my group come from all walks of life; the director of strategy for a unit from a major company, a nurse, commodity trader, dentist, venture capitalist, lawyer and a financial analysts for an aerospace company.  All have experience in mountains, although highly varied.  Most importantly, all seem like fine people to send the next three days with tied to ropes, sleeping in crowed tents, and cursing crampons.

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IMG delivers the expedition to Paradise. The wind is very strong, and the posted wind chill is 38 degrees.

The expedition started on Thursday morning — loaded up out packs at IMG headquarters and traveled east up the Nisqually River to the Paradise Visitor Center.  I had weighed my pack early in the morning – full water bottles and mountaineering boots attached, and it was a marginally agreeable 46 pounds.  But, alas, I forgot I had to take a group food package that would eventually become my dinner and breakfast the next two days.  I don’t know how much my package weighed, but probably on the order of 5 pounds.  So, loaded pack was about 50 pounds, about 45 pounds more than I ever run with on the trail.  This was the only thing that I was truly dreading;  pre hip and knee replacement 50 pounds would be no problem, but not positive what the next 3 days would hold.

Although the morning felt cool at Ashford, it was down right cold at Paradise.  The wind was blowing strongly, and the posted wind chill was 38 F.  IMG assigns 1 guide for every 2 climbers, so our team was 12 strong.  Our lead guide was Cedric Gamble, and had the job of both assessing risk and assuring the team that were are super strong climbers; thus, we heard both the comment that the wind was amazing and not at all usual, and surely this weather will pass and all is good.  I had my Garmin GPS watch and tracked the multi day climb.  By my watch, the starting elevation was about 5100 feet. The path wanders out of Paradise and climbs up to Pebble Creek (this was about 3 miles by the route we were on, and a gain in elevation of 1900 feet).  Hiking is easy even with the full pack, although the wind gust literally blew me over a couple of times.

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Climbing the Muir Snow Field – putting on our mountaineering boots.  The views to the south are spectacular with Mount Adams, St. Helens and Hood dominating the horizon.

Crossing Pebble Creek, the trail runs into the Muir Snowfield.  The snowfield is not a glacier but a perennial mass of snow that is both slick and wet.  The path for our expedition is to follow the snowfield up to Camp Muir, some 2.2 miles and 3000 feet elevation gain away.  We changed out of our trail shoes into mountaineering boots for the trek up to Muir — this meant that my pack was lighter, but it also meant that I had to wear the plastic mountaineering boots, which are  composed of an outer hard plastic waterproof shell and an insulating inner boot. These are heavy and warm, and I absolutely hate them.  Too heavy and hot, it was like running in dress shoes.  Over the next couple of days I would realize that these boots, when outfitted with crampons, where by far the most difficult aspect of the entire expedition.

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IMG tent at camp Muir – a great restaurant.

About half way up the Muir snowfield we ran into another IMG team descending the mountain.  A rather sobering and somber conversation took place between the two teams — the descending team had not been able to summit because of the high winds and had turned around at 13,000 ft elevation.  It was very difficult to imagine that one could not summit on a clear day and that there were many factors that determine a successful climb.  The rest  of the first day’s climb is easy into Camp Muir.  Muir is an assortment of small buildings situated on a ridge that separates the snowfield from the Cowlitz Glacier.  The buildings serve as a way station for climbers, and IMG has a small room there where the team can bunk down for the night.  The room is about 20 x 20 feet, and is a couple of plywood shelves to role out your sleeping bags.  Pretty small quarters, but shelter from the wind (it also turns out the expedition members don’t really snore nor have nocturnal gaseous emissions).  The IMG guides have a tent that serves both as the communal restaurant and their sleeping quarters.  Dinner at the IMG tent was a very pleasant surprise, and suddenly I felt very guilt for my mental grousing about carrying that five pounds of community food.  Dinner serves as a chance for all the team members to learn about each other — and I learned far more than I ever thought possible about pediatric dentistry, the incredible attributes associated with living in Coeur d’Arlene and climbing Aconcagua (I am jealous).

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A sketch of the east side of Rainier (from Crandell, 1969). The path for our ascent crosses the head of Cowlitz Glacier, then follows the rock spur below Gibraltar Rock up to cirque of Ingraham Glacier over looking Little Tahoma Peak. The original summit of Rainier went from Point Success to Liberty Cap – before a major eruption 5500 years ago, Rainier was 16,000 feet high.

Friday morning the trek really begins — we practice ice axe skills, crampons on ice, and roping up groups of climbers.  We cross over Cowlitz Glacier and then have a short hike up what is called Cathedral Gap;  the Gap section is bare rock and our passage is in our crampons, a first distasteful snippet of walking on rock and dirt while wearing sharp spikes of metal.  After a relatively short hike we arrive at the high camp located on the upper reaches of Ingraham Glacier.  Ingraham Flats is a moderately sloping section of ice at an elevation of 11,500 ft.  The camp is four tents for the climbers, two more tents for the guides, and small kitchen carved in the ice and snow.  The views are breath taking; the sounds are unnerving.  The Flats are framed by Gibraltar Rock to the south and the Disappoint Cleaver to the north.  Gibraltar lords over the camp as vertical cliff of nearly 800 feet, composed of layers of eruptions and lahars past.  Every few hours rocks fall from the cliffs, a not so subtle reminder that Rainier is always changing.  I also peer up at the ice of the head of Ingraham Glacier and think about the disastrous ice fall in 1981 that took the lives of 11 climbers.  It is the worst climbing accident in American history, and to be in it’s shadow is a reminder that gravity is unforgiving.  I decide it is best not to ask about the accident with the other members of the team.

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High Camp – Ingraham Flats, on Ingraham Glacier.  Over my left shoulder is the Cleaver, a nasty stretch of rock that is the heart of the climb to the summit (which is visible some 3000 feet above us in the center of the photo).

We have “dinner” at 3:45 on Friday so that we can be in the tents by 5:30 pm.  This is to facilitate a 1:00 am wake up call and a 2 am debarkation for the summit.  Sleep that night seems fine for me (better than most of my hotel visits to Washington DC every couple of weeks), but most of the team is beginning to feel the effects of altitude.  Living at 7400 feet elevation has its rewards!  Breakfast at 1:15 is instant oatmeal and coffee.  I opt for multiple cups of coffee and pass on the oatmeal.  At 11,500 the boiling point of water is about 185 degrees F instead of the sea level value of 212 degrees, so the coffee is tepid.  No matter, it is still nice fuel.  The morning is cool – my thermometer that I left just outside the tent reads 28 degrees F.  The wind is still though, so it is quite easy to dress comfortably.  Unfortunately, before we rope up to cross the glacier and head up the cleaver we remove layers to assure that we don’t over heat on the climb.  That means it is cold when we start our trek.  The climb is steep, and the half moon gives a nice glow, but mostly you look at the ground in front of you illuminated by your head lamp as travel.

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High Camp from Disappointment Cleaver. This picture was taken on the descent, mid-morning.  The tiny dots are our tents at the high camp.

The Cleaver is an 800′ elevation climb on rocks.  It is technically the most difficult part of the entire ascent.  Not particularly physically challenging, but the combination of large blocks of Andesite, crumbly scoria, and even some obsidian means that every step of the crampon encased boot is a challenge. Around 3:30 we finally finish with the Cleaver, and are back on the welcome crunch of ice.  The guides lead us back and forth up the south face of Rainier until we finally cross the lip of West Crater about 7 am.  The sun is just rising, and the winds are calm.  Unbelievably majestic.  Crossing the lip of the crater is considered a summit, but I know that we are across the crater from the true high point on Rainier.  Several of us drop our packs and hike the couple of hundred yards to the northwestern rim and climb up to the Columbia Crest, the “true” summit of Rainier.  We arrive there about 7:30, and revel in the success of the trek.

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Summit Team at Columbia Ridge. Just below me is the USGS marker for the elevation.  The marker was placed in 1956 – my birth year.

The views from the summit are both spectacular and disappointing. The skies are clear, and one can easily pick out every major volcano in the Cascades well into Oregon. However, the humidity in the air gives a sense of haze in the distance that one never sees from the summit of a 14er in Colorado. The crater itself is magnificent. A stone circle created by an eruption a few thousand years ago, it has dozens of fumaroles all along the rim. Wisps of steam give hint to the hot rock not far below the surface. I applied the sniff test to several of the fumaroles, and only caught the faintest notion of sulfur; mostly was just moist stream.

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West Crater

Around 8 am we began our long trip reversing our footsteps back to Paradise. By my Garmin we had hiked 12.2 miles and with the ups and downs (mostly ups!) we had gained 9600 feet elevation. The journey down was more difficult than I expected – not because it was a physical challenge, but because the sun was shining and the views were extraordinary! I wanted to stare and ponder the magic landscape, which meant I did not want to focus on traveling on a rope along an icy and steep trail. The descent back to the top of the Cleaver went by uneventfully, and I was able to get a picture of the moon setting over the top Mt. Rainier.

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Rainier Descent – moon setting over the rim of the crater.

The traverse down the Cleaver was by far the most difficult part of trip down. We are all a little tired, and those damn boots and crampons! I did manage to stab myself in the left leg with the crampons from my right boot. I drew blood, and it is only appropriate as a sacrifice to a great mountain. We finally get back to high camp for a brief rest, and some lunch. The journey back to Camp Muir was pretty trivial, and we stop for some water at the IMG tent. All that stands before us and the end of the trek is the Muir snowfield – how hard can that be? However, we decide to keep on the crampons to cross the field since it is soft and slick. Drudgery! But unexpectedly, the slog was made tolerable by the fact that it was Saturday, and there was a menagerie of folks climbing the snowfield from Paradise. We saw people in shorts, skirts, tennis shoes, formal wear, and of course, flip flops! Consider that these snowfield adventurers had invested hiking more than 3 miles and 2000 feet elevation gain, you have to wonder how much thought went into their apparel. One of the most humorous moments of the entire journey was when one of our teammates engaged a woman in a long dress in conversation on the snow and said “you can do it!”. He was being positive, but also preposterous! Finally, at Pebble Creek we shed our boots and crampons, and all is right with the universe.

The trek up Rainier was a spectacular experience. I am fortunate to have combined the wonder of a high mountain climb with a favorable group of colleagues, and wonderful guides. I could not have been more delighted – but of course, I got something a little extra. On the flight home Sunday morning the American Airlines flight to Dallas took off to the south out of SEATAC and flew towards Rainier. Once we reached the Nisqually River the pilot took a hard left and flew right over Paradise, and suddenly out my window was the entire picture of my trek. Fabulous!

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Passing over Rainier on the way home (9/14/14). The image is high resolution so click on it and expand. The various way stations are labeled.

Rainier will one day erupt, and will no longer be the high point of the Cascades. I am grateful that I got to experience the great mountain in its finest state – and mood.

Ice in the Mountains: Gravity, Glaciers and Garibaldi

Everything is flowing — going somewhere, animals and so-called lifeless rocks as well as water. Thus the snow flows fast or slow in grand beauty-making glaciers and avalanches; the air in majestic floods carrying minerals, plant leaves, seeds, spores, with streams of music and fragrance; water streams carrying rocks – John Muir

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Mount Garibaldi from Squamish Chief

The Coastal Range in southwestern British Columbia is a land of spectacular mountains, and home to the southernmost icefields in North America.  The rapid rise of the mountains from the inland passage between Vancouver and Victoria Island, along with prevailing winds bringing marine moisture from the Pacific means that there is ideal conditions to foster alpine glaciers.  We visited Whistler (of 2010 Winter Olympics’ fame) with the hope of visiting some of the glaciers before they disappear — yes, although there are many alpine glaciers, they are in rapid retreat probably due to increasing atmospheric temperatures.  To be sure, ice is every where, but a simple comparison of photographs from the early part of the 20th century to the scenes today shows that the ice is disappearing.

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The Garibaldi Ranges

Whistler is located in a broad mountainous zone, known as the Coast Range, which extends from Southwestern Yukon along the entire coast of British Columbia (1600 km long, average 300 km in width). There are numerous subdivision of the Coast Range, and the southern most extreme is called the Garibaldi Ranges. Whistler sits in the middle of the Garibaldi Ranges,  and the high point is Wedge Mountain (elevation 2892 m) which is just north of Whistler.

wedgemont1Wedge Mountain viewed from Wedgemount Lake – to the left of the peak is Wedge Glacier

The geology of the Garibaldi is complex, and it has taken geologists decades to unravel the imprints of ancient subduction, plate fragment accumulation, and volcanism to develop the history of these mountains. The Coast Range was built in response to the complex interactions between the North American Plate and various smaller plates, most of which have now disappeared.  About 130 million years before the present an oceanic plate named the Insular Plate was subducting beneath North America – along the western margin of the Insular Plate another oceanic plate was subducting beneath Insular called the Farallon Plate. Farallon-Insular subduction zone built a volcanic island arc on the Insular plate (the modern day analog to Farallon-Insular-North America is the Phillippine Mobile Belt).  The relative plate motions between these three plates meant that the Insular Plate was doomed to demise – the relative motion of North America was to the west, and Farallon to the east, shrinking and squeezing Insular until it ceased to exist 115 million years before present. The Insular Island arc was “accreted” to the North America Plate forming the Insular Belt of folded and metamorphosed rocks “glued” to North America by a large granitic batholith.  Once the Insular plate disappeared the Farallon was now subducting beneath North America, and a Continental arc (not unlike the coast of Washington and Oregon today) formed and was populated with large stratavolcanoes.  The mountainous zone associated with the arc was known as the Coast Range Arc, and was active from approximately 100-85 mybp.  About 85 mya the Farallon plate broke into fragments, and the northern section which was subducting beneath modern day BC became the Kula Plate.

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Squamish Chief – a 2000′ dome of granite formed as the Kula Plate began interacting with North America

For the next 30 million years there was a massive influx of granites and formed one of the largest granitic bodies in North America and are now exposed in the Coast Ranges. The Kula plate eventually developed a relative motion that shut down the subduction beneath BC, and began subducting beneath southwestern Yukon and Alaska by 50 mybp. This shut down most of the volcanism within the Coast Ranges, although some stratavolcanoes like Mount Garibaldi remained active until more recent times.

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The ice of the Garibaldi Ranges

Alpine Glaciers and Ice fields

Glaciers are defined as bodies of persistent ice with surface areas exceeding about ½ of a square km.  In general glaciers grow and shrink, and this is promoted by the flow of ice;  snow falls on part of the glacier and is compressed into crystalline ice which creates a gravitational stress “forcing” the surrounding ice to flow downhill. The ice at the leading edge of the flow eventually melts, either through encountering higher ambient temperatures in the atmosphere or the warm (above freezing) waters of the ocean.  A special category of glaciers are called Alpine Glaciers, which form near the crest of Mountains, and are feed by the seasonal fall of snow and melting at the lower reaches to the mountain, particularly in the summer.  The area that a alpine glacier adds ices is called the neve, and typically is a bowl shaped region which is called a cirque.

tantalusicefallA large alpine glacier in the Tantalus Range next to the Garibaldi Ranges. The large “head” of the glacier is known as the neve

Glacier motion is controlled by two things:  the strength of the ice, and the stress applied to the ice.  The crystal structure of all ice occurring in the natural environment is hexagonal – all snow and ice on Earth forms in a six-fold symmetry that typically forms sheets lying on top of one and another.  The figure below shows a typical arrangement of these sheets;  the red ball-and-stick figures are the oxygen atoms and the bonds to the 2 hydrogens in a water molecule.  The bonding between the sheets is weak, and under horizontal stress the sheets “slide” past one and another.  For small bodies of ice the stress loads introduce by gravity are modest and the ice deforms mostly as an elastic material.  However, when ice exceeds a thickness of about 100 feet it begins to deform plastically, meaning that it flows.  The flow is characterized by the Glen-Nye law that relates flow (strain rate) to stress (the weight of the ice) and temperature.  The flow of ice in a glacier is typically lowest along the base because of frictional resistance with the underlying rock.  Occasionally, glaciers also move by a process known as basal sliding where the glacier is lubricated by melt water (and making the frictional resistance disappear).

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Massive ice forms sheets that are weak and flow when subjected to shearing stresses

The fate of a glacier is controlled by mass balance; ice is added to the top of an alpine glacier and ice is removed by melting at the toe or sublimation to the atmosphere (the removal of ice is called ablation).  There are many factors that can upset the mass balance, including temperature, rate of precipitation, and sudden movement that breaks apart the glacier.  The temperature effect appears obvious – if the glacier interacts with a warmer atmosphere less ice is formed.  However, this is actually a complex interaction and sunlight subliming the ice can increase during cool but clear conditions.  The precipitation is more straightforward; no moisture, no ice formation. All glaciers in the mountains of British Columbia are in retreat, meaning that the toe of the glacier is melting faster than new ice is arriving from the neve.  This phenomena is of alpine glacier retreat is well documented globally for mid-latitudes.  There are fairly good observational records for the shape of glaciers for many areas stretching back a couple of hundred years.  Francois Matthes noted that global temperatures where abnormally cool from about 1350 to 1850, and he called this the Little Ice Age (LIA).  Most early observations of alpine glaciers occurred during the LIA; after 1850 when the global temperatures increased there was widespread glacial retreat. Around 1930 this retreat slowed, and for many regions glaciers actually grew until about 1980.  Since 1980 glacial retreat has become universal, and appears to correlate with the global mean temperature rise.

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The picture above from Koch et al. (2009) shows the Warren Glacier (which is located within the Garibaldi Ranges) photographed three different times.  This glacier was in retreat with the end of the little ice age (comparing 1912 to 1929), but was episodic in growth/retreat until 1977.  Since that time the Warren Glacier has been in rapid retreat. Over that last 20 years it has retreated at and average rate of 20 m/yr.  Not all glaciers in the Garibaldi are retreating at the same dramatic rate, but all are retreating and thinning.  A linear projection (which is always a bad idea, but simple to do!) suggests that 90 percent of the Garibaldi Ranges glaciers will disappear by 2035.

Enjoy the ice and marvel at its power while it lasts

Alpine glaciers are a truly beautiful feature of high mountains.  The ice also strongly shapes and carves the bedrock leaving both sharp and rounded structures that define the peaks.  It is rather remarkable that ice could have such at profound erosional signature considering the softness of ice.  However, like sandpaper glued with tiny corundum fragments, glacial ice lifts loose rock and freezes the into place along the base of the glacier.  As the glacier moves downhill the rock fragments cause abrasion and “polish” the underlying bedrock.  The abrasion produces “rock flour” that eventually flows away in the glacial melt.  The rock flour is what causes glacial melt water to be various shades of milky green.

wedgemontlakeWedgemount Lake is colored green by the rock flour from the Wedge Glacier

All of these glacial process, along with the ice, are most likely to be gone before 2050.  This will mean that we have different mountains, different vistas, and different impacts.  The nature of global warming is such that the die is cast — nothing is going to reverse the temperature increases in the next 100 year.  This means that it is imperative to visit these nobel mountain architects now, and appreciate their geologic legacy.

Cahokia: Geology and the Birth and Death of Cities

Civilization exits by geological consent, subject to change without notice.  Will Durant (American Philosopher)

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The American Bottom is a broad lowland directly east of St. Louis, Missouri along the eastern shore of the Mississippi River.   The area is about 175 square miles, and is a 10-mile wide floodplain of one of the largest confluences of rivers in North America.  Throughout the American Bottom there are abandoned meanders of the Mississippi River, swamps, and bogs.  800 years ago it was also home to the largest pre-Columbian settlement north of present day Mexico City. This city is known as Cahokia Mounds today, and is thought to have reached a peak population in excess of 20,000 people at its height about 1250 AD.  Why did Cahokia rise as a great city, and why did it eventually fail (in fact, it had completely disappeared by the time Columbus landed in the Caribbean)?  The story is, of course, one of geology.

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Star shows the location of Cahokia and the American Bottoms

Visiting St. Louis for the 4th of July holiday always means I am looking for some elevation to hike – a quandary along the Mississippi embayment.  My son suggested that we go to Cahokia Mounds and walk the “hills” of the ancient city.  I knew little about the people of the Mississippian culture that occupied the American Bottom from 600 to 1400 AD, except that they used the vast river system of what is the modern Midwest for transportation and that they build ceremonial “mounds” or elevated earthworks.  Cahokia was a large urban center that grew to at least 4000 acres and had at least 20,000 inhabitants at its peak, and probably had governing influence over three times that number of people along the Mississippi River.  Today the Cahokia is a State Historic Site – a park that covers about 3.5 sq miles, and has 80 mounds.  The largest mound is called Monks Mound, a four tiered platform approximately 100 feet high covering 14 acres.

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Monks Mound from the south in the Grand Plaza

Monks Mound was built by hauling soil (which was rich in clay and organic materials) from bog quarries called “borrow pits”.  Coring of the Mound shows that it was constructed in several phases, each from different borrow pits.  It probably was assembled over a couple of hundred years, and its increasing height had to do with “elevating” the status of successive rulers.  The top of Monks Mound had a large building or cluster of buildings- most modern interpretations are that these were the residence of the Cahokia ruler and court. Monks Mound derives its name from a community of Trappist monks that briefly resided in the mounds at the beginning of the 19th century and were thought to planned to build an monastery on top of the mound (luckily, the monks moved on before executing their plan).

Monks Mound overlooked a large compound that contained ceremonial burials, a plaza (called the Grand Plaza), and storage facilities for foodstuffs.  The entire region was surrounded by a wooden stockade complete with look out towers.  Due west of Monks Mound is a curious circle of that is thought to have served the purpose of a sun calendar.  The circle had a number of wooden posts or pillars that appear to be aligned with shadows cast for a rising sun during the solstices and equinoxes.  The functional similarity to Stonehenge in England has led to the naming of this site as “Woodhenge”.

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Why did Cahokia rise to become a major urban center?  The most obvious explanation is geography based – the American Bottom is an incredibly fertile valley and the nexus of three major rivers, which could serve as a transportation hub. Just north of American Bottom the Missouri and Illinois Rivers join the Mississippi. The Missouri River is the longest river in North America (over 2,300 miles in length) and drains the Rocky Mountains of Montana and Wyoming.  The Illinois River is much shorter (only 300 miles long) but claims a drainage basin of nearly 30,000 sq miles in Illinois and Indiana.  The Mississippi River drainage basin covers the area between the Missouri and the Illinois Rivers – combined, the three rivers drainage basins cover nearly a quarter of the United States.  The wide extent means that at least one of the rivers would flood on an annual basis, and would deposit sediment, renewed with nutrients in the American Bottom.

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The converge of three great rivers: Missouri, Illinois and the Mississpii

There is a theory of cities and urban centers based on their projection of power.  There are “consumer cities” and “producer cities”.  In this definition consumer cities are a center of government and military power – the classic example was Rome in the ancient world, and Washington DC today.  Goods flow to consumer cities, and presumably, culture flows to the countryside.  Producer cities, on the other hand, produce goods and commercial services and export these to derive their power and influence.  Often producer cities rise in importance, become consumer cities, and eventually collapse when they lose their political power.  Cahokia is probably an example of this producer-consumer-collapse cycle.  The early Cahokia inhabitants developed a strong agriculture base – including annual planting of corn.  The soil was rich enough to support the production of grains in excess of the immediate needs of the inhabitants; these grains (at least the corn) could be exported to surrounding regions in exchange for other goods.  Copper from Michigan, sea shells from Florida, and gemstones from Mexico have been found in Cahokia excavations.  The flow of wealth was facilitated by the strategic location of the city with respect to the rivers.  This flow of wealth, in turn, fostered the growth of a governing structure, and Cahokia eventually transformed to a consumer city, and political center.

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Michelle and David looking at the diorama of village life around Cahokia

It is clear from the archeology of Cahokia that structures associated with rituals were mostly built after 1100 AD;  by 1250, at the height of the cities power, the core of Cahokia was dominated by ritual structures – a signature of government.

The population of Cahokia began to decrease after 1250 AD, and by the beginning of the 16th century it was completely abandon.  Some archeological work suggests that the diet of inhabitants began to change after about 1250 – a decrease in the ratio of protein to carbohydrates, which suggests that game animals had been hunted to scarcity.  It is unlikely that a climatic condition like an extended drought had much impact on Cahokia because of the three great rivers, although flooding and consequent soil renewal may have become less frequent.  However, it is clear that the collapse of Cahokia was more rapid than its ascent.  There are no strong indications of the city being “sacked”, but other centers on the southern Mississippi River rose during the 15th and 16th Century suggesting either a political struggle for power, or simply filling of the void left by the Cahokia decline.  The most likely explanation is a combination of environmental factors – a half a millennia of farming had depleted the soil and hunting had diminished the game animals such that the weight of the government could not be supported.  Geology gave the city its birth, but in the end the resources were over taxed.

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The picture above is from Monks Mound looking across the Mississippi to St. Louis on July 5, 2013.  The atmosphere is pregnant with humidity, but the modern “Cahokia” is obvious.  St. Louis was founded in 1764 by a French trading company based on it strategic location of the nexus of Missouri and Mississippi rivers.  Today it is still a producer city – but how long that epoch will last remains to be seen.

The Mountains are on Fire

God has cared for these trees, saved them from drought, disease, avalanches, and a thousand tempests and floods. But he cannot save them from fools ― John Muir

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Smoke plume billowing above Pajarito Ski Hill (Tuesday evening, June 4; Steve Black photo)

On Friday (May 31) a downed power line started a wildfire in the west-central region of the Jemez Mountains near a deep drainage called Sulfur Creek on the western margin of Redondo Peak.  The fire burned uphill on the eastern side of the drainage rapidly, and was named the Thompson Ridge Fire (although not on Thompson Ridge).  The sight of smoke in the Jemez was visible in Los Alamos by 5 pm and the entire town held their breath, thinking “here we go again”.  By Saturday afternoon smoke from the plume began to collapse on Los Alamos, and the smell of burnt pine caused an even stronger visceral reaction triggering memories from June 2011 when the Las Conchas Fire swept around the town, led to a week-long evacuation, and charred more than 150,000 acres.  The question on many peoples’ minds is “why?”  It certainly seems that the entire Jemez is going to be soon burned, leaving a high elevation desert.  The 1996 Dome fire, the 2000 Cerro Grande and the 2011 Las Conchas Fires have changed the scenic vista of the eastern Jemez profoundly and probably for hundreds of years.  Each of these fire was bigger than the last:  The Dome fire was 16,500 acres, Cerro Grande was 48,000 acres, and Las Conchas was over 150,000 acres.  The obvious question is “are the fires getting bigger and more frequent?”

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The Jemez Mountains are a unique alpine island created by the Jemez Volcanic Complex (JVC) that was active for about 800,000 years beginning around 1.4 million years before the present.  The JVC lies along a line of volcanoes that arcs across New Mexico from the southwest to the northeast, known as the Jemez Lineament.  In the southwest the San Carlos Volcanic Field (in Arizona) anchors the Lineament, and it passes through Mt Taylor near Grants, the Jemez, and finally terminates in the Raton Volcanic Field.  There is no real good explanation for the Jemez Lineament, and geologists continue to debate both its cause and significance.  The JVC is the largest of the volcanic fields on the Lineament.  The geologic map above shows the Jemez Mountains.  The Jemez Mountains surround the Valles formed during the collapse of the JVC about 1.1 million years ago.  In the middle of the collapse crater a great “resurgent dome” was pushed up by the death throes of a great volcano.  This dome is Redondo Peak – which is not an eruptive volcanic cone, but an extruded dome.  Redondo Peak is the high point in the Jemez at 11,258 ft elevation.  The uniqueness of the Jemez was recognized by the first geologic expeditions of the west; John Wesley Powell himself visited the Jemez in the 1880s and described it as a giant volcanic field (anyone interested in the geology of the Jemez should read Fraser Goff’s book “Valles Caldera: A Geologic History”).

The volcanic field and Redondo rise above the surrounding New Mexico highlands to form a roughly circular mountain range.  This range has its own flora and fauna – or at least it did before the great fires of the last 25 years.  Elevations above about 7200 feet were dominated by ponderosa pine and various fir and spruce.  After a fire the pine is replaced by scrub oak and lower growing vegetation. Craig Allen has studied the fire history and vegetation of the Jemez, and has found dramatic change.

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This change is from both fire and mortality of the pine forest due to prolonged beetle attacks.  The figure above shows a color-coded map of the Pajarito Plateau, centered on Los Alamos, and where fire or beetles have affected our forests.  In twenty years 90% of the forest have been subject to stress.

The question of “why” is the Jemez burning can be partially answered by looking at the fire history of the mountains.  There are various ways to do this, including coring trees looking for scars from ancient fires, and looking at the peats in the meadows within the Valles and looking for preserved ash and charcoal layers.  When Allen and other researchers did this they reconstructed a fire record that stretches back nearly 10,000 years.  There are literally tens of thousands of fires over this period, and some strong trends are worth noting in the last couple of hundred years.

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The figure above shows the location of nearly 5000 fires in the 20th century, along with the Cerro Grande Fire.  The great bulk are small, local wildfires, probably almost always caused by lightning. There is evidence in the distant past of very large fires – probably as large as Las Conchas – all across the Jemez. There is a moderate correlation with those large fires and large-scale drought. However, before the mid-20th century wildfire was most commonly characterized by small, frequent fires.

Beginning in the late part of the 19th century man began to have a significant impact on the ecology of the Jemez.  Livestock grazing in the Jemez became “big business” and the removal of the understory grasses probably suppressed wildfire.  The cows and sheep ate the grasses that supported spreading the fires.

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In the 1930s the Jemez became a lumber supplier, and the region began to be heavily logged.  This is particularly true for Redondo Peak and the Valles Caldera which were in private hands, and were not subject to the regulation of the Forest Service.  The picture above shows a logging road from the mid-1930 on the northwestern side of Redondo.  Today, logging roads are still seen across the Jemez, especially as spirals up the various domes.  The lumber “boom” ended, and the forests began to fill in.  Livestock grazing dropped dramatically, and new Federal oversight of wildfire suppression caused the forest cover to densify.  By the 1960s the forests were much more dense then 200 years previous.  The pathways for fire were increasing.

Over the last 2000 years there have been periods of drought and high precipitation.  Around 1990 we entered a period of drought, and the window between 2000-2010 was likely the driest decade in a millennium.   This drought stressed the trees, and they became much more susceptible to disease.  In particular, the pine bark beetle attacked, and will eventually kill, more than 1.3 million acres of ponderosa pine in New Mexico and Northern Arizona in the period of 2002-04.  The beetle problem is complex – stressed trees are one issue, but also the density of the forest allows the beetles to spread much more rapidly than in the past.

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Nate McDowell and colleagues at Los Alamos produced the figure above that shows the loss of forest due to the beetles and fire.  It is fair to say we are in a long-term, profound, change of our forest.  The Jemez is not unique, but it does seem to be at the confluence of disease, drought, forest “management” and finally, the encroachment of man.  Before 1950 the vast majority of wildfire was caused by lightning.  However, since 1990 more than 85% of fires have a man-made fingerprint.  For the four major Jemez fires in the last 25 years it is all man-made;  The dome fire was caused by a camp fire, the Cerro Grande started as a controlled burn (what a total fiasco – and to this day an unpunished event), Las Conchas was started by a downed power line as was the present Thompson Ridge.

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Although it is dangerous to predict the fate of nature, it certainly seems that large fires are going to continue in the Jemez for years to come.  A break in the drought would help, but a short break would only promote the understory growth which would become the match stick once drought resumed.  We are standing on the cusp of a major change for our beloved Jemez, and can only hope that luck and nature conspire!