The Magdalena Group of Pennsylvanian age and, in ascending order, the lower tongue of the Abo Sandstone (herein named the Danley Ranch Tongue), the Hueco Limestone, the upper tongue of the Abo Sandstone (herein named the Lee Ranch Tongue), and the Yeso Formation of Permian age are well displayed in the southern part of the Sacramento Mountains. The contact of the Pennsylvanian rocks with the overlying Permian rocks is unconformable throughout the area. Locally the relief before deposition of the Abo was so great that in places the Danley Ranch Tongue of the Abo is absent because of nondeposition. At these places there is prominent angular discordance between the Pennsylvanian and Permian rocks.
The red beds of the Danley Ranch Tongue interfinger with and grade southward into the overlying Hueco Limestone. Red beds of the Lee Ranch Tongue of the Abo Sandstone also grade southward into the Hueco and cannot be traced south of the southern part of the Sacramento Mountains. The Lee Ranch Tongue is believed to be stratigraphically lower than the Deer Mountain Red Shale Member of the type Hueco Limestone. The herein named Otero Mesa Member of the Yeso Formation is believed to occupy an intermediate stratigraphic position between the Lee Ranch Tongue and the Deer Mountain Red Shale.
