Finlay Limestone

The Finlay Limestone is a geologic formation in western Texas, southern New Mexico, and northern Chihuahua. It preserves fossils dating back to the early Cretaceous period.

Description

The formation is composed of massive gray limestone with a few thin beds of brown sandstone, with a total thickness of. It is exposed in the Finlay Mountains, the Sierra de Juarez, and the Cerro de Cristo Rey uplift. The formation overlies the Cox Sandstone and is overlain by the Del Norte Formation.

Fossils

The formation is highly fossiliferous, containing fossils characteristic of early Cretaceous Albian and Comanchean age.

Economic resources

The formation includes carbonate replacement deposits of lead, zinc, and silver in northern Mexico, along the Chihuahua CRD belt.

History of investigation

The formation was first defined by G.B. Richardson in 1904 and assigned to the Fredericksburg Group.