NEW GEOLOGIC MAPS (1:24000) OF THE EASTERN PART OF BIG BEND NATIONAL PARK, TX

Recently published detailed geologic mapping in the eastern part of Big Bend National Park (BBNP) includes the Boquillas Formation and younger Cretaceous and Tertiary strata as well as the upper part of the Buda Formation. The mapping covers a north-south transect of the BBNP including the Solis, San Vicente-Rio Grande Village, Roys Peak, McKinney Springs, and Dagger Flat-Bone Spring Quadrangles (1:24000). Geologic mapping (1997-2010) by R.W. Cooper, T.M. Lehman, J.B. Stevens, M.S. Stevens, and D.A. Cooper was used to compile the geologic quadrangle maps. These maps update previous mapping by Maxwell and others (1967). The new mapping illustrates both Laramide- and Basin and Range-related deformation. The Boquillas Formation ranges in age from the late early Cenomanian to possibly late Santonian based on identification of macrofauna (ammonites and inoceramids) and also includes the Cenomanian-Turonian, Turonian-Coniacian, and Coniacian-Santonian Stage Boundaries. The maps are available from the Texas Bureau of Economic Geology, Austin, TX and compliment other recent mapping by the USGS and the Texas Bureau of Economic Geology.