Monday, October 20, 2014

"Head Smashed In"... um, sounds like a great place to visit...

The High Plains have their quiet times. Sure, there are the vicious winter storms,  the days when the wind blows hard, and the summer thunderstorms. But other times the wind may be just a light breeze through the grass, maybe a hawk soaring overhead. Or a huge marmot standing guard on a sandstone outcrop. But I can also stand in this place and imagine a similar quiet day a few thousand years ago. It's quiet, but then the ground starts to tremble, and a dust cloud rises over the crest of the low hill. The birds startle and take flight, the marmot dashes for cover, and suddenly over the ridge comes a thundering herd of buffalo. They're stampeding, and the leading animals start to shift directions, but then suddenly a strange figure jumps up, yelling and waving limbs. It might be a wolf, it's hard to tell in the panic, so the herd shifts direction once more. The leaders now realize they are headed for a precipice and they try to stop, but it's too late. They go over the edge, pushed by the animals behind. They impact on the rocks and bones below, most of them dead immediately. In a moment it is over. People emerge from their hiding places and start to butcher and process the meat, bones and hides. It has been a successful hunt and they will have enough food and furs to make it through the difficult winter.
There is a seven story building in this picture. Can you see it?
The First Nations people of Canada and Native Americans of the High Plains depended on the buffalo for survival. They made use of the meat, the fat, the bones, and the hides. But anyone who has ever seen one of these immense animals knows that they would a dangerous adversary in a hunt. They can be as long as eleven feet and weigh a up to a ton. They can easily outrun a human, capable of speeds of 35 miles per hour. Though it was done, bringing one down was a difficult and dangerous proposition.
We were in southern Alberta on our Northern Convergence tour of western Canada, and were making our last stop in the country at Head Smashed In Buffalo Jump World Heritage Site. At Head Smashed In and similar localities, the geology provided a safer way to hunt the animals.
At the edge of the prairies where the mountains rise from the plains, the land is not so flat as it is further east. The convergence far to the west compressed and pushed up the Rocky Mountains. The soft Cretaceous mudstones and sandstones underlying the high plains were also pushed up into broad swales and low hills. Ice, water, and wind exploited fractures in the rock, and erosion ate away at the edges of the hills, exposing vertical cliffs of sandstone. Just such a cliff is exposed in the Porcupine Hills outside of Fort Macleod, Alberta. For at least the last 5,800 years, people have utilized the cliff here to capture and kill buffalo.
A spring emerged from the base of the cliff, providing water at the kill site (the green watercourse is visible in the picture above). The Old Man River flows in the flats below, providing sheltered sites for villages.
Tipis have become such a stereotype that some might think that most Native Americans lived in them. I groan inwardly whenever I see one at "Indian Stores" or southwest tourist traps. But the tipi at Head Smashed In was an appropriate sight. The tipis were an excellent shelter on the windy plains. They were portable, an important consideration for a nomadic people. I know of paleontologists in the region who tried to camp in modern nylon tents, but gave them up for tipis, which were more comfortable and more durable in windstorms.
The site was declared a World Heritage Site in 1981 for its archaeological value. Excavations 39 feet deep in the cliff show a complex history of buffalo hunting going back 5,800 years (two spear points show activity in the area as far back as 9,000 years. The visitor center was constructed to blend in to the landscape, and does so admirably (see the picture above). There are trails to the top of the cliff where some cairns from the hunts can still be found. A trail also loops around the base of the cliff. One of the nice surprises inside the well-designed center was a hallway lined with numerous paintings and artwork by First Nation students representing the oral histories of their culture.

About the name of the place. In the Blackfoot language it is called Estipah-skikikini-kots. Legend has it that a young man decided to watch one of the buffalo hunts from the base of the cliff. He picked a bad spot, and was crushed beneath the weight of the falling animals. The name doesn't exactly inspire confidence in the site as a destination when traveling in the region, but it is indeed a fascinating place to visit. It's full of history, but it is also a place of wide-ranging views and scenic beauty, and despite the name, serenity.

Sunday, October 19, 2014

The Sierra Nevada Underground: How does a newly discovered pristine cave look? Finding out at Black Chasm

There are caves and there are caves. Many of them were discovered long ago, and the easily accessible ones suffered grievous damage. In earlier days, cave decorations (speleothems) were broken off as souvenirs in the sadly mistaken belief that they would grow back quickly. Today's cave vandals have no such excuse. They break and destroy for sheer maliciousness. It's sad either way because caves don't recover, not in any kind of human time-frame. Their special kind of beauty is lost to us.
That's what makes a few caves extra precious. A few weeks ago, I explored Crystal Cave in Sequoia, which by virtue of being in a national park and being discovered by park personnel, was protected before catastrophic damage was done. It was developed for tourism, and millions of people have walked its passageways and yet it was protected by and large from the worst abuses.
The tour I was on yesterday was a different circumstance. Black Chasm cave near the Gold Rush town of Volcano in the Sierra Nevada Mother Lode is a privately owned cavern. It was discovered in the 1800s but the "chasm", a ninety foot deep crevice, prevented the miners from ever getting into the remote reaches of the cave. Access required technical climbing skills, and people who go through that much trouble rarely have vandalism in mind.
A decision was reached in the 1990s to develop the cave for tourism, making a total of six such caves in the Sierra Nevada: Crystal Cave, Boyden Cavern, Mercer Caverns, Moaning Cavern, California Cavern, and Black Chasm. A stairwell and boardwalk were pinned to the edge of the chasm, allowing for access to the nicely decorated room beyond. A room never despoiled by vandals, or dirtied by sooty lanterns and torches.
For those who have only seen the usual soiled yellow-brown stalactites and stalagmites, the pearly white formations are a revelation about what a cave can look like. Beautiful examples festoon the walls. But Black Chasm has an additional feature that is astounding. Stalactites on LSD!
Growing out of the walls at odd angles, and growing in totally random orientations, helictites are strange and rare cave formations. They are easily broken off, and are undoubtedly one of the first formations to disappear from caves. They are present in Black Chasm in, shall we say, large numbers. Really large numbers, enough that the cavern was granted National Natural Landmark status, a federal designation that recognizes the value of natural features on private lands, including agreements to protect the resource.
The exact process by which helictites form is not clearly known. They are most likely related to capillary action of water squeezing out of microscopic openings in small stalactites and precipitating small amounts of calcite. Because water under pressure can be squeezed upwards, the development of the helictites is not governed by gravity.
The number and variety of helictites in the Landmark Room of Black Chasm is simply stunning. I haven't been to every cave in the world, but I would not be surprised if these are some of finest examples in existence (although I am always open to correction on such issues).
Black Chasm Cave, as noted before, is a privately owned business. They are there to make a profit, but they have done a good job of protecting their cave, and I recommend a visit. They offer discounts for educational groups (they can accommodate up to 22 people at a time, so large classes would need to split into two tours). More information about the cave can be found here. Tell them Geotripper sent you!

Friday, October 17, 2014

Northern Convergence: Tragedy at Crowsnest Pass


Frank was a coal mining town of around 600 people in 1903. The coal seam ran along the base of Turtle Mountain, so the town was established there as well. The Canadian Pacific Railway also crossed the area on its way to Crowsnest Pass.

The local First Nation people did not like Turtle Mountain. They called it the "Mountain that Moves", and refused to camp in the area. The Europeans had no such worries, and mining of the coal was well underway. In the early morning of April 29, 1903, a shift of 17 miners was working deep underground. For weeks there had been strange things happening in the mine. Timbers holding up the tunnel walls would splinter and break for no apparent reason. Coal would occasional "mine itself", crumbling out of the seams overnight when no one was around. Small earthquakes were occasionally felt underground. The miners knew that the collapse of mine tunnels was an ever-present danger, so they may not have been overly surprised to hear the explosive concussion followed by an ominous silence. They were trapped, no doubt by a cave-in. They began to assess their situation. Soon, water was pouring into the tunnels, making a bad situation even worse.

The normal passage to the surface was blocked, but one of the miners knew that a second coal seam might be close enough to the surface that they could hack their way out. They started digging for all they were worth, gasping in the increasingly toxic air. One by one, the miners gave out. They weren't dead, but they just did not have the energy to pick up their tools. Only three of them were still working when they broke through to the surface. Rocks were still falling from above, so they couldn't yet escape, but they had fresh air, and they quickly cut another opening beneath a protective overhang. After thirteen horrible hours they emerged at the surface to find their experience was only a part of an even larger tragedy. A gigantic avalanche had buried part of their town, killing between 70 and 90 people. The miners had been given up for dead, so their appearance was some small bit of good news in the midst of the horrific event.
It gets to a certain point when driving through the mountain wilds of British Columbia and Alberta that one expects that trees will be growing just about everywhere. The region has plenty of precipitation through the year so things will be green. Approaching Crowsnest Pass during our recent Northern Convergence tour, we were struck by the sudden appearance of an absolutely barren slope. It doesn't take long to realize why, as the highway crossed a huge debris field covered with gigantic boulders. It was the debris avalanche that destroyed so much of Frank back in 1903.
http://en.wikipedia.org/wiki/Frank_Slide

The slide was truly epic in scale. Totaling 30 million cubic meters (82 million tons), the avalanche was 1,000 meters (3,300 ft) wide, 425 meters (1,394 ft) high and 150 meters (490 ft) deep. It spread laterally over level ground, covering three square kilometers. The rocks had flowed over the surface like a thick liquid at speeds of up to 70 mph (112 km/hr). The entire event was over in less than 2 minutes.
 The slide was probably inevitable. The limestone layers had been folded into a huge anticline (upward pointing fold) with thrust faults at the base, on top of weak Cretaceous sediments. Glaciation had oversteepened the flanks of the mountain. Fissures sliced deep into the rocks allowing water and ice to accumulate, weakening and wedging the rocks apart. The mining at the base of the slope was quite possibly a contributing factor.
Source http://www.uleth.ca/vft/crowsnest/slidedebate.html
The Frank Slide was the worst mass-wasting disaster in Canadian history. But life went on. The mines were reopened (a horse who worked in the mine was actually found alive after a month underground). The town grew even larger for a few years, but by 1917 the coal mines closed down. Today about 200 people live in the village nearby, and an interpretive center has been constructed that provides information on the extraordinary event.

We headed into nearby Pincher Creek for the night. It was our last night in Canada, but we still had plenty yet to see, on both sides of the border..

Source: http://occ.crescentschool.org/geography/physical/folding/frankslide.html


Wednesday, October 15, 2014

Northern Convergence: We'll Call it "Rock": The Okotok Erratic

There is a big rock out on the high prairie near Calgary, Alberta. That all by itself is a bit of strangeness. It's even more strange because it is around a hundred miles (160 km) from the cliff in which it originated, up in the Rocky Mountains in Jasper National Park. The Blackfoot Indians had a creative name for the rock, Okatok, which in their language means, um, "rock". These names always sound better in the original language! For whatever reason, the spelling changed a bit to Okotok.
The Blackfoot people had a great story for how the rock got to this spot, a myth that could have served as the inspiration for the rock monster in the movie "Galaxy Quest". Their legendary trickster Napi was resting on the rock on a hot day, so he left his cloak on the rock, saying "Here, I give you my robe, because you are poor and have let me rest on you. Keep it always". Murphy's Law dictates that it soon got cold, and the rain began, so Napi asked for the return of his robe. The rock refused so Napi grabbed "his" cloak. In a moment, the rock was up and running after him! Napi called on his animal friends, the Bison, Antelope and Deer, and none of them could stop the gigantic rock. When all seemed lost, a bat flew straight at the rock, collided with it, and the rock was split in two! The bat had saved Napi, and got a squashed face for all his trouble (such things have to be explained somehow...).*
A smaller erratic a few hundred yards from the Okotok Erratic
The geologists tell a different story, and were it not for the overwhelming evidence it would seem just as fantastical. During the Pleistocene Ice Ages, the continental ice sheets covered all of the region thousands of feet deep. Up in the Rockies at Jasper a huge rock slide dumped massive boulders onto the surface of the glaciers emanating from the high peaks. The glaciers flowed eastward onto the High Plains, eventually meeting up with the vast ice sheet that originated near Hudson Bay. The two ice sheets didn't mix, so the two "rivers" of ice flowed together towards the south. The gigantic rocks from the cliff in Jasper were dumped in a line many miles long where the glaciers moved together. These isolated boulders are called glacial erratics.
The rock is sometimes claimed as the largest erratic boulder in the world, but I have no way to evaluate the claim. It certainly is huge, and worthy of a visit (it is a few miles southwest of Calgary). The Blackfoot or other First Nation peoples were certainly impressed. Faint pictographs can still be seen on the flanks of the rock.
Pictographs are symbols painted on the rock. Petroglyphs are chipped into the rock.

This is a continuation of our Northern Convergence tour of British Columbia and Alberta. In this case, I guess "convergence" refers to the two masses of glacial ice. We concluded our visit and headed back towards the Rocky Mountains and Crowsnest Pass to check out a not-so-long-ago tragedy. More on that next time.

*The Blackfoot legend is  loosely rephrased from interpretive signs at the park.

Tuesday, October 14, 2014

For Modesto Area Friends: Celebrating the Art of Science at the Science Community Center of MJC, Oct. 15, 2:00PM

If you are in the Modesto region, you are invited to a reception for the artists of the Science Community Center. We have a number of interesting works that are being celebrated tomorrow at 2:00 PM. I would love to run in to some of you!

I didn't sculpt anything, but I have a number of my bird photographs mounted on the walls in some of the meeting rooms. I've been exploring the rather diverse population of native birds who inhabit the wilder corners of our campus, and discovered some three dozen species so far and counting. You can see a lot of them at Geotripper's California Birds.

Where'd Everyone Go? Why is it so Quiet? Dealing with Dinosaurs in Drumheller


We continued our Northern Convergence exploration of British Columbia and Alberta by heading over the Great Plains for several hours to reach Drumheller, the self-proclaimed (and fairly reasonably so) Dinosaur capitol of the world. On a field trip, our students would normally expect to spend time in the field, but sometimes there are museums that simply must be seen. The Royal Tyrrell Museum of Paleontology at Drumheller is one of those places. It's worth the long drive over the flat prairie.
Lest you think the cheesy 150 foot long Tyrannosaur is part of the museum, don't worry, it is not. This baby is downtown at the chamber of commerce. It just begs to be photographed though, but watch out where it steps. You never know what could get caught between its toes...
Toe lint...
The museum is far more than a "dinosaur" museum. It takes its mission as a museum of paleontology very seriously with a nicely designed tour through the entire development and evolution of life on planet Earth throughout 4.56 billion years. And dinosaurs! Lots of them!
One of the problems with older vintage museums is that they displayed their exhibits in the same way that they organized their collections: as a vast and highly organized repository. I remember a museum from my youth where they had the bird's egg room, and the eggs were displayed in linear cabinets, one after another, filling the room. With lots of eggs. In long rows. Not very inspiring to a kid, despite the extreme value of the collection for research.
An overview of the Dinosaur exhibit hall at the Royal Tyrrell.
Museums have caught on to the necessity of using their exhibit space to tell a story, and what story could be better than the astounding adventure of life on Earth? The exhibits lay out the methods of paleontology (how we know things), and lead into displays of what we have discovered. The "pathway" leads the visitor through a series of interactive displays starting with the earliest, most primitive forms of life right up through the Pleistocene megafauna, and how they related to the ecosystems of the present day.
The Burgess Shale of Yoho National Park on display.
They have used an excellent mix of genuine specimens and life-size replicas to give a sense of the true scale of ancient forms of life, whether microscopic or gargantuan. I was especially impressed with the Dunkleosteus, a massive armor plated fish that lived in Devonian time (around 420-360 million years ago). I knew of the 30-35 foot length of the fish, but there is nothing quite like being confronted with the gaping toothless jaw, the cutting edges formed from the armor plates. To see a living one would be a bizarre and terrifying experience.
Dunkleosteus, a terror of the Devonian seas. And an elevator to escape through...
Much of the museum is devoted, not surprisingly, to the rich paleontological history of Alberta and the rest of Canada. There has been a treasure trove of dinosaurs found in the vicinity, and they have been given a lot of space in the exhibit. No kid with a love of dinosaurs could come away disappointed. But with the additional exhibits of the other major groups of animals, they may instead be inspired to learn more about the rich stories that bookmark the existence of dinosaurs on the planet.
Except for maybe this kid...but he's about to be eaten anyway.
An additional treat at the museum is the opportunity to get out and explore the starkly beautiful landscape that surrounds the museum site. Several trails lead out onto the exposures of the late Cretaceous Horseshoe formation, which once provided the coal reserves that were once mined here, and a large number of dinosaur species..
Badlands adjacent to the Royal Tyrrell Museum
These lands where the dinosaurs once roamed are now dominated by the hair- and fur-bearing creatures, although a few of the avian dinosaurs still remain as well.
Yes, these are our overlords now...
We spent four hours at the museum and wanted to stay longer, but there were other sights on the road ahead. We took off across the prairie once again.

Monday, October 13, 2014

Civilization Exists By Geological Consent...So does life in the Great Valley

Sandhill Cranes at the San Luis NWR
The Sandhill Cranes are returning to their winter home in the Great Valley of California! In the next few weeks there will be 20,000 of them arriving at the Merced National Wildlife Refuge a few tens of miles south of Modesto. They will be sharing space with hundreds of thousands of other birds, including Snow Geese, Cackling Geese, Ross' Geese and many others. To many pundits, the Great Valley of California is a rotten place to live (see my comments about this from yesterday's post). But if you are a bird, the valley is next to paradise. It represents survival, and the reasons are geological.
Sandhill Cranes at the San Luis NWR

The Great Valley is 400 miles long, and around 30-40 miles wide, running from Redding at the north end to Bakersfield in the south. It is amazingly flat, with total relief of only a few hundred feet. Two major river systems, the Sacramento and San Joaquin, provide a richness of water in what would otherwise be desert or near-desert. A huge range of habitats existed here at one time, including short-grass prairies, riparian floodplains, oak woodlands, lakes, and vernal pools. Although agriculture and urban development have co-opted some 95% of the valley floor, there are still pockets of native environments remaining.
Killdeer at the Merced NWR

The valley originated as a large shallow sea called a forearc basin along the vast subduction zone that once existed across the entire west coast of North America. The convergent boundary was eventually changed, and the San Andreas transform took its place. The Coast Ranges rose in the last few million years, acting as a rain shadow, and preventing the rivers from finding an easy path to the sea. The Sacramento and San Joaquin rivers flow outward through the Carquinez Strait, but several other rivers, including the Kings, Tulare, and Kern, don't reach the sea. Prior to settlement and diversion of the rivers for agriculture, they ended in large shallow lakes at the south end of the San Joaquin Valley. The lakes are dry today.
Yellowlegs (Greater?) at the San Luis NWR

Though so much of the original valley habitat is gone, a few critical wetlands remain and are preserved as a string of National Wildlife Refuges. These refuges are a critical component of the migratory flyway for millions of birds. Some simply pass through, stopping long enough to eat and gather energy for their long journey, but others spend the winter here, and some stay all year.
California Quail at the San Luis NWR

Many tourists pass through the Great Valley without a second thought on their way to Lake Tahoe, Yosemite, or Sequoia/Kings Canyon, but at this time of year they are missing an awesome show of the variety and diversity of nature. There is nothing quite like seeing and hearing the spectacle of 10,000 geese taking off all at once. There are hundreds upon hundreds of bird species who spend at least part of the year in the valley, not to mention a rich variety of mammals, reptiles, fish and amphibians. The valley for all its problems can be a fascinating place to spend some time.
Great Blue Heron at San Luis NWR
The San Luis National Wildlife Refuge Complex includes 45,000 acres of protected lands within an hour's drive of Modesto, my home base. There are a number of hiking trails (all level, imagine that!) and several auto tours, including those at the San Luis and Merced Units where I took all of these pictures today. I think we saw or heard at least three dozen species of birds in just the four hours we spent exploring.
Northern Shovelnose at the Merced NWR

We were entranced by the hundreds of Sandhill Cranes arriving by the minute in the setting sun. The video below provides a sense of how it felt...



Don't just pass through the Great Valley on your next trip to California. Check out our valley and find out why we call it "Great". Two places to get information: the headquarters for the San Luis NWRC near Los Banos, and in a few short months, the Great Valley Museum on the west campus of Modesto Junior College. 

The title quote comes from Will Durant, and in its entirety reads "Civilization exists by geological consent, subject to change without notice".