|Name||Black Peaks Member of Tornillo Formation|
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Claystone (Bed)
|Comments||Sandstone and clay; sandstone at base, conglomeratic, crossbedded, gray to grayish white, some cannonball concretions split into platy layers; clay, mottled gray and deep dark-red; vertebrate fossils common; thickness ranges from 284 to 866 ft, crops out in northern part of Big Bend NP.|
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.