Category:Carlile-Ft. Hays contact sand with pyrite

Sample found while exploring for sand at the contact of the Carlile Formation and the Fort Hays Limestone Member of the Niobrara Formation. The Codell Sandstone member of the Carlile is generally missing south of Big Creek, with not sand found at the old Yocemento quarry. This is about 6 miles further south. We found signs of the contact bentonite and very few samples of sand concretions, apparently cemented with pyrite. The underside of the Inoceramus shell is free of pyrite, but shows juvenile Ostrea congesta.