Hueco Formation
The Hueco Formation is a geologic formation in west Texas and southern New Mexico. It preserves fossils dating back to the early Permian period.
Description
The formation is composed most of massive gray fossiliferous limestone with some shale and sandstone, with a thickness in excess of. It overlies the Panther Seep Formation with a slight disconformity, and its base is typically a thick biostromal limestone bed. The formation unconformably underlies the Wilkie Ranch Formation. It intertongues with the Abo Formation in the southern San Andres Mountains.In the Robledo Mountains, the Hueco is promoted to group rank and divided into the Shalem Colony, Community Pit, Robledo Mountains, and Apache Dam Formations. In the Hueco Mountains, the uppermost formation is the Alacran Mountain Formation.
The Hueco Formation is contemporary with the Abo Formation and represents continued marine sediment deposition south of the prograding Abo deltas.