Mina Grande Formation (TXPmg;0)

State	Texas
Name	Mina Grande Formation
Geologic age	Phanerozoic \| Paleozoic \| Permian [Guadalupe]
Original map label	Pmg
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.
Primary rock type	limestone
Secondary rock type
Other rock types
Lithologic constituents	Major Sedimentary > Carbonate > Limestone (Bed)
Map references	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
Unit references	Bureau of Economic Geology, 1979, Emory Peak--Presidio Sheet, Geologic Atlas of Texas, University of Texas at Austin.
Geographic coverage	Presidio