Word Formation (TXPw;0)

State	Texas
Name	Word Formation
Geologic age	Phanerozoic \| Paleozoic \| Permian [Guadalupe]
Original map label	Pw
Comments	Characterized by great lateral variation in thickness and lithology. Thickest to southwest; thins to north and northeast. Divided into an eastern and western facies, with transition taking place in region of Hess Canyon. Coarser sediments to southwest. Eastern facies: (ascending) cherty limestone, in part dense and bituminous, in part light gray and crystalline; siliceous shale, some quite sandy; interbedded limestone layers; about 300 ft below top is a persistent sandstone bed; at top is a buff sandy dolomite. Western facies: contains 4 thick limestone beds. Third bed from base contains rich ammonite fauna, the upper bed is quite cherty, and all are abundantly fossiliferous. Base is marked by a thin layer of platy bituminous limestone. Thickness 580 to 800 ft.
Primary rock type	limestone
Secondary rock type	sandstone
Other rock types	shale; dolostone (dolomite)
Lithologic constituents	Major Sedimentary > Carbonate > Limestone (Bed) Minor Sedimentary > Carbonate > Dolostone (Bed) Sedimentary > Clastic > Mudstone > Shale (Bed) Incidental Sedimentary > Clastic > Sandstone (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	Brewster - Pecos