Munn Formation (TXPm;0)

State	Texas
Name	Munn Formation
Geologic age	Phanerozoic \| Paleozoic \| Permian [Guadalupe]
Original map label	Pm
Comments	Dolomite, limestone, siltstone, and sandstone. Upper part--mostly dolomite and limestone, fine to coarse grained, in part oolitic, medium to thick bedded, white to grayish orange; some siltstone and fine-grained quartz sandstone proportion increases southward. Lower part--mostly dolomite and dolomitic limestone, fine grained, very thick bedded, light brownish gray to pale yellowish brown, weathers a distinctive brown; thin beds of siltstone and fine-grained sandstone scarce, more numerous northward. Marine megafossils and microfossils. Thickness 450+ ft.
Primary rock type	dolostone (dolomite)
Secondary rock type	limestone
Other rock types	siltstone; sandstone
Lithologic constituents	Major Sedimentary > Carbonate > Limestone (Bed) Sedimentary > Carbonate > Dolostone (Bed) Minor Sedimentary > Clastic > Mixed-clastic > Sandstone-mudstone (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, 1968, Van Horn-El Paso Sheet, Geologic Atlas of Texas: Bureau of Economic Geology, The University of Texas at Austin, scale 1:250,000.
Geographic coverage	Culberson