Mina Grande Formation

Mina Grande Formation
State Texas
Name Mina Grande Formation
Geologic age Permian; Guadalupe Series
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone (Bed)
Comments Limestone, hard massive, dolomitic, reefy, surface rough and hackly with brecciated appearance, gray to yellowish brown; serves as chief silver, lead and minor gold host rock (Presidio deposit) in Shafter district; also host of mineralization at Red Hills Cu-Mo porphyry system in Presidio Co.; thickness up to 400 ft in Shafter district, 25 ft in Upper Cibolo Basin, missing in many places due to pre-Cretaceous erosion.
References

Bureau of Economic Geology, 1979, Emory Peak--Presidio Sheet, Geologic Atlas of Texas, University of Texas at Austin.

Bureau of Economic Geology, 1992, Geologic Map of Texas: University of Texas at Austin, Virgil E. Barnes, project supervisor, Hartmann, B.M. and Scranton, D.F., cartography, scale 1:500,000.

NGMDB product
Counties Presidio