Pillbug tracks in ash from Mt. St. Helens

Reader Nancy Weidman (who supplied the Wind River boudinaged basaltic dike images from earlier in the week) sent me this interesting note: Your ichnoanalogue post reminds me of the insect or pillbug tracks I found in Mt. St. Helens ash deposited in Missoula, Montana. At least some of the tracks, if I recall correctly, ended … 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

Spheroidal weathering in Columbia River basalt

I’m in Idaho for the Rocky Mountain section meeting of the Geological Society of America. Yesterday, I was delighted to tour around in eastern Washington’s Channeled Scablands with my colleague Bill Richards (North Idaho College). I took a lot of photos, but here are two to start – lovely examples of “onion skin” style weathering … Read more

Friday fold: Hoh Hoh Hoh

Another guest submission for the Friday fold – this is becoming a major trend! Peter Selkin‘s student Rick Schwartz loaned us this one. Peter describes the outcrop this way: The rocks here are Miocene turbidites of the Hoh lithic assemblage (sometimes called the “Hoh Terrane”) exposed at Beach #4 on the Pacific coast of the … Read more