Today’s deskcrop is a piece of the Cambrian Potsdam Sandstone from near Alexandria Bay, NY. The Potsdam at this locality lies nonconformably over gneisses of Proterozoic age. One can see bedding laminations in this sample as well as alteration zones at the top and bottom of the sample marking where groundwater flowing along bedding planes has begun to weather the sample. I also GigaPanned the roadcut at this locality, but I’ll hold that view for one of this coming weekend’s “Outcrop” posts.
Explore this and all of my 2010 Deskcrops and Outcrops in Google Earth!