Saturday, January 30, 2016

The Devil's Postpile National Monument

The Devil's Postpile

It's one of California's most unique landmarks: the towering columns of columnar basalt looming high over the valley floor is a postcard image for California and the National Park system. Devil's Postpile is a national monument in the Eastern Sierra Nevada Mountains and is a hotspot for tourism between May and November. But enough introduction now, and on to the really interesting part: the geology!

Tuesday, January 5, 2016

Return to Marble Canyon

The famous crossroads sign at Marble Canyon
My most recent trip was mostly return visits, and since I've written on the exploration of Marble Canyon before, I figured I could now write the Informing part of it. This part of the Cottonwoods, including Marble and Cottonwood Canyons, is almost entirely end-paleozoic era limestones and marbles between 350 and 290 million years old. A lot of the rock along the canyon includes black balls and lumps of a microcrystalline chert. These result from colonies of algae that have fossilized and stand out prominently against the grey limestone.