Geotripper got a new camera for his birthday, and has been taking pictures of mountains. I haven’t posted enough pictures since I got my camera in December, so here’s a view of my daily commute:
Here, let me label it for people who don’t make a habit of seeing geology in landscapes (picture below fold):
The dreaded Mancos Shale, which is found on all the lower slopes in the background, was deposited near the western shore of the great interior seaway of North America, about 90 million years ago. My colleagues who are into fossils tell me that there are some massive clam shells in it, if you look in the right places. When sea level fell, the sea receded to the east, and my area became covered with a series of sandy islands or deltas like today’s Gulf of Mexico coast. The cliffs of the Mesa Verde Group (named for the place with the Ancestral Puebloan ruins) are the remnant of the old shoreline.
The La Plata Mountains in the background are a local culprit for the disappearance of the ocean here. They’re cored by igneous rocks, a shallow magma body that dates (probably) to around the time when the dinasaurs went extinct, and the sedimentary rocks have been bent into a dome above them. They’ve also got ore deposits in them, historically mined, and currently the source of conflict between neighboring landowners.
The pinyon and sagebrush are the native vegetation at 6800 feet. There aren’t many places in town where you find them, now. They’re growing on a terrace of glacial outwash, remnant of the ice that ended in town during the last glacial maximum. The terrace is covered by reddish loess – wind-blown silt deposited beyond the end of the glaciers as they receded. It sticks to shoes during this season.
The blowing snow was the reason I regretted not wearing a hat on the day I took this picture. Brr.
Even with cold ears, though, it’s not bad as far as commutes go.