Chasing Volcanoes and Overthrusts: Exploring the Pacific Northwest and the Northern Rocky Mountains

Mt. Shasta from Interstate 5 in the vicinity of Red Bluff and Corning. Photograph by Mrs. Geotripper

A few weeks ago I had the privilege of attending a field trip on Kilauea volcano on the Big Island with Don Swanson and Tina Neal of the Hawaii Volcano Observatory (and I'm probably not done with those blogs yet, by the way). Along the way, Don parked our van at the end of a road, and then made a seemingly useless U-turn before turning off the vehicle. He said in passing that when studying active volcanoes, he preferred to park facing away from the volcano...saved time when needing to evacuate in a hurry. With the stories he told, his habit seemed to make a lot of sense.

I was thinking about that as we drove north on Interstate 5 in the northern Great Valley on the first day of our exploration of the Pacific Northwest and northern Rocky Mountains. We were a band of 19 students and staff on a two week journey, camping our way across some of the most spectacular landscapes on earth. Looking out the windshield I couldn't help but think that we were headed right at some particularly young and active volcanoes, such as Mt. Shasta (above).

The Sutter Buttes north of Sacramento in the Great Valley. Photo by Mrs. Geotripper.

These volcanoes are part of the Cascades Range, which extends from Lassen Peak at the south end, to the vicinity of Garibaldi Peak in British Columbia. The "fire" beneath the volcano is derived as the oceanic crust off the coast sinks into a vast subduction zone. When the sinking slab reaches a depth of several tens of miles, water is liberated which changes the melting point of the minerals in the rock in the crust above. Buoyant magma rises into the crust, and eventually some of it leaks out, producing the eruptions that build these volcanoes.

The subduction zone is disappearing in geologic terms as it replaced by the growing San Andreas fault (don't panic too much, it's happening at a few inches a year). Volcanoes at the south end have been going dormant and then extinct. Once possible example is the unusual set of hills in the midst of the Great Valley north of Sacramento. The Sutter Buttes are the eroded remnants of a volcano that erupted around 1.6-1.4 million years ago. They're west of the main axis of the Cascade range, but then again so is Mt. St. Helens. Most research suggests that the volcano is more closely related to volcanic fields in the California Coast Ranges.

Lassen Peak from the west. Photo by Mrs. Geotripper.

Soon after passing Sutter Buttes, Lassen Peak became visible off to the east. The 10,457 foot high volcano is a smaller type of volcano called a lava dome or plug dome composed of viscous silica-rich dacite lavas. The original volcano erupted about 27,000 years ago, but it reawakened in 1914, had a major eruption in 1915, and continued to sputter for a few more years after that. It was made into a national park soon after. It was not on our itinerary on this trip, but we spend time there on our fall semester explorations.

Black Butte on the flank of Mt. Shasta. Photo by Mrs. Geotripper.

We passed one more prominent volcano before we reached the end of the road on the flanks of Mt. Shasta. Black Butte is a large looking volcano when viewed from Interstate 5 around Mt. Shasta City, but is a very small volcano compared to the adjacent edifice of Mt. Shasta  (it can be considered a part of Shasta). Like Lassen, it is a plug dome that erupted about 9,800 years ago.

And...Geotripper is Back! What a Long Strange Journey it's Been...

I'm back from a journey to the Pacific Northwest and the Northern Rocky Mountains with 18 students and volunteers. We've been gone for two weeks, and Wi-Fi was practically nonexistent, and I was constantly on the run anyway, so total internet silence ensued. I'm a bit too tired to be doing any heavy writing, so I am starting out with a bunch of photographs of the our furred, feathered and scaled friends that we met while on the road...enjoy!

Hitting the Road in the Best Way: Into the Pacific Northwest, and With My Students!

It's the time of year I love the most, our field season, when my students and I hit the road. We are making a grand loop, heading north along the spine of the Cascades, with stops at Mt. Shasta, Lava Beds, Crater Lake (above), St. Helens, and Mt. Rainier. We'll then head across eastern Washington through the Channeled Scablands, and climb into the northern Rocky Mountains at Glacier National Park. From there we'll head south into Yellowstone and Grand Tetons National Parks, and cross the Basin and Range Province on our way back home. Y'all have my permission to let up on the heat wave by the time we come back (stay cool and safe). Needless to say, postings on Geotripper will probably be sparse, but I'll give it a try if I can (maybe the laundromats have Wi-Fi out there).

Explore the Pacific Northwest and Northern Rocky Mountains with Geotripper! June 17-July 1, 2017

Grand Tetons National Park, Wyoming

Be forewarned. This post is a TRAP! It is designed to draw you in, weaken your defenses, and cause you to do something different than everyday life. Warning given...

Have you ever dreamed of hitting the open road and finally seeing those places you've dreamed about, but haven't acted on that dream yet? What if you found out about an excursion that doesn't just tour, but allows you to learn the geology and history of those wild places? A tour on which you can even earn college credit? AND, a tour that is affordable? Maybe this is the one...

Mt. Shasta, a Cascade volcano in northern California

From June 17-July 1, 2017, the geology department of Modesto Junior College will be conducting a field studies course (Geology 192) in the Pacific Northwest and Northern Rocky Mountains. It will be a three semester unit course designed for our community college clientele: first year geology majors, potential geology majors, and community members (especially teachers) interested in geology and natural history. We will develop the necessary geological background prior to and in the early days of the trip, so people of all backgrounds are encouraged to attend. The total cost is $800 which will include all food, camp fees, entrance fees, transportation costs for the trip. The tuition cost for the three units of semester credit will be around $180 (out of state tuition is higher, around $200 a unit, which is still a deal). The only additional costs should be for showers, laundry, books and other souvenirs, and junk food (we provide healthy food for the most part; if you want Twinkies you are on your own!). We will be camping each night, and the school provides the transportation (vans). The excellent meals are planned by our professional volunteer staff, and cooked by the participants under their watchful eyes.

Lava Tube in Lava Beds National Monument

What will you see and experience? On the 17th we'll leave MJC and drive north through the Great Valley of California and arrive at the south end of the Cascades Range. The huge edifice of Mt. Shasta looms over the north state at 14,163 feet, and still is potentially active. It last erupted in 1786. Depending on snow conditions, we'll climb to the 8,000 feet level at the old ski bowl and have a close look at the rock and ash deposits. We'll continue north and end the day at Lava Beds National Monument near the Oregon border. There will be chance to explore some lava tubes while we are there.

The view from Smith Rock State Park in Oregon

We drive through Oregon the next day, with possible stops at Crater Lake National Park and Newberry Crater (depending, once again, on snow conditions). Camp will be at Tumalo State Park. The following day we will explore Smith Rock State Park (above), Mt. Hood, and the Columbia River Gorge (if there is time we will climb Beacon Rock in the gorge). The third camp will be at Seaquest State Park at the foot of Mt. St. Helens in southern Washington.

Mt. St. Helens in Washington. It erupted in 1980 and 2004

The following day will be devoted to the exploration of Mt. St. Helens (weather allowing!). We'll then descend the eastern flank of the Cascades (including a close look at Mt. Rainier) and drive onto the Columbia River Plateau, a vast basalt plain that covers much of eastern Washington and Oregon. Camp will be at Wanapum State Park on the Columbia River near Vantage.

Dry Falls State Park in Washington. The floodwaters covered this entire landscape to a depth of 300 feet during the Spokane floods.

The next day we will view the evidence for vast floods that swept across the plateau during the Pleistocene ice ages. The discovery of these floods by J Harlan Bretz in the 1920s and the long road to acceptance of the hypothesis by the geological community is one of the great stories in the history of geology as a science. We'll have a look at the Channeled Scablands, Soap Lake, and Dry Falls as we travel east through Washington. We'll spend the night at Riverside State Park in Spokane, Washington.

Lake McDonald in Glacier National Park

We'll head through the copper mining districts of Idaho and into Montana where we'll see more evidence of the ice age floods, including the Camas Prairie where ripplemarks 30 feet high can be found. We'll end the day in a special place, Glacier National Park on the Montana-Canada border. We'll spend two days exploring the park, with chances at several hikes. The park is a showcase of glacial erosion, but the glaciers that exist in the park today are expected to be gone within a decade or two because of global warming.

Saint Mary Lake in Glacier National Park, Montana

When we leave Glacier, we'll head south through the high plains on the east side of the Rocky Mountains and end the day at the KOA in Bozeman, Montana. We'll check out the Museum of the Rockies, and depending on snow conditions, explore some of the high mountains that surround Yellowstone, and eventually drive the Beartooth Highway into Yellowstone, America's oldest national park. We'll spend two days exploring this incredible park.

Yellowstone Falls in the Grand Canyon of the Yellowstone River

There is the Grand Canyon of Yellowstone, and a menagerie of incredible animals, including elk, bison, moose, bighorn sheep, and if we get really lucky, wolves.

Wolf near Norris Geyser Basin, Yellowstone National Park

Then there are geothermal features for which Yellowstone is so famous. Grand Prismatic Spring, for instance, and 70% of the world's geysers (there's lots more besides just Old Faithful!).

Grand Prismatic Spring, Yellowstone National Park

We'll then head south and spend two days at Grand Tetons National Park with time for some spectacular hikes. Then we start the road home with a drive through northern Nevada to Berlin/Ichthyosaur State Park to see the fossilized remains of the behemoth swimming reptiles from the age of the dinosaurs. Finally, we expect to see Mono Lake and the high country of Yosemite National Park. If snow blocks our path, we head home over Sonora or Carson passes.

Big Geyser (not Old Faithful!) in Lower Basin, Yellowstone National Park

It's hard to describe the wonders that exist across the Pacific Northwest and Northern Rocky Mountains without getting an overwhelming urge to get up and leave right away. If you are interested in joining us this summer, please check out the course web page at http://hayesg.faculty.mjc.edu/GeologyPacificNorthwest.html and join our Facebook page at https://www.facebook.com/groups/185168445318910/. If you are in the Modesto region, we are having an information meeting on Monday, April 10 in the Science Community Center on the west campus of the Modesto Junior College at 7 PM in SCC 326 (attendance is not mandatory to go on the trip). We hope you will join us!