Last week I was lucky enough to go on a rafting trip through the Grand Canyon. The trip was sponsored by the Geological Society of America as a field forum, where geologists from a wide range of disciplines could come together and debate the formation of the Grand Canyon. The range of proposed ages of the canyon is huge – from 6 million years old to 70 million years old! So, in celebration of 150 years since John Wesley Powell’s expedition boated down the canyon, we took part in vigorous debate and experienced incredible vistas.
Marble Canyon, after setting out from Lees FerryOur boats! Loaded up with all of the food, clothing, cots, sleeping bags, and beer for almost 30 peopleHiking along the top of a slot canyon in Surprise Valley.Travertine precipitated out of springs forms new rocks on the canyon walls, and cement old river gravels that can be used to determine past heights of the river bed.The oldest rocks in the Grand Canyon form the basement, making up the walls of Granite Gorge, a section of the river with lots of rapids. The granite is highly resistant to erosion, and is over a billion years older than the sedimentary rock sitting above it. During that time, the granite was eroded into a landscape with hills and valleys, which you can still see as a preserved landscape from over 500 million years ago.
