Lake Valley Limestone


The Lake Valley Limestone is a geologic formation widely exposed in southwestern New Mexico. It preserves fossils dating back to the lower to middle Mississippian.

Description

The Lake Valley Limestone consists of gray cherty limestone with thin shale beds. It overlies the Caballero Formation and is overlain by Pennsylvanian beds. The total thickness is.
Members of the formation, in ascending stratigraphic order, are the Andrecito, Alamogordo, Nunn, Tierra Blanca, Arcente, and Dona Ana Members.

Fossils

The formation contains abundant crinoids as well as corals and brachiopods. The Andrecito and Alamagordo Members contain foraminifers characteristic of the Kinderhookian while the foraminifers of the Tierra Blanca Member are Osagean.

History of investigation

The formation was first named by E.D. Cope in 1882 for exposures in the Sacramento Mountains. In 1941, Laudon and Bowsher removed the lowermost beds into the Caballero Formation and divided the Lake Valley Limestone into the Alamgordo, Arcente, and Dona Ana Members. In 1949, they added the Andrecito, Nunn, and Tierra Blanca Members.