pleistocene
U-turn
Scotland was glaciated during the Pleistocene “Ice Ages:” The signatures of glaciation are manifold in a scene like this. Most prominent and easily recognizable is the broad, relatively flat-bottomed U-shaped valley. Now check this one out: That’s a U-turn in a U-shaped valley: the valley is first gouged to the right, then turning around and … Read more
Flood deposits of Glacial Lake Missoula outburst floods
Two weeks ago, I went on an awesome, informal field trip to eastern Washington State to visit the Channeled Scablands for the first time. My collegue Bill Richards of North Idaho College picked me up in Spokane and drove me halfway across Washington and back to Moscow, Idaho, over the course of a day. This … Read more
Varves along Hawk Creek, Washington
Heading into the Columbia River Plateau, Callan and his colleague Bill Richards make a detour in search of some varves from Glacial Lake Columbia. They find them, a credit to the authors of “Washington Rocks!” – the new book from Mountain Press.
Glaciotectonic thrust at Waubonsee Community College
Glaciers can cause thrust faults! Explore an example from a trench south of Chicago.
Student guest post: the Belt Supergroup in Glacier National Park
As longtime readers know, late summer is when my Rockies students submit their final projects – web-based explanations of key geologic sites they examined during the trip. Today, I offer you a guest blog post by student John Leaming. You’ll notice that I’m not *completely* absent from the post, however – I make a couple … Read more
Glacial striations
Today, I thought I would share some images of lovely “textbook” glacial striations from rocks I saw in the Canadian Rockies this summer…
An examination of the Horseshoe Canyon Formation in eastern Alberta
An expert on the deltaic depositional setting of eastern Alberta’s Horseshoe Canyon Formation shares field evidence and expertise with Callan’s students.
Aden Crater
That’s Aden Crater, a Pleistocene shield volcano in southern New Mexico. Here’s what it looks like from above (Google Maps view): I also noted the position of two nearby maar craters: Kilbourne and Hunt Holes. When you climb up to the edge of Aden and look in, you see the congealed and fractured remnants of … Read more
Western Inyo gravel strata
This image is from the canyon in which route 168 ascends the Inyo Range from Big Pine, California. View is to the south/southwest. Those are gravel layers that dip gently westward. I think they’re associated with the underlying Waucobi Lake Beds, which are Plio-Pleistocene in age. The lake beds are made of finer stuff, but … Read more