Abstract

The area comprises the states of Kansas, Oklahoma, Arkansas, Louisiana, and Texas. Devonian strata crop out in parts of Oklahoma, Arkansas and Texas. They are also widely distributed in the subsurface, being present over much of eastern Kansas, parts of eastern, southeastern, southcentral and southwestern Oklahoma, northern, central and western Arkansas, and central and western Texas. Devonian strata have not been penetrated in Louisiana. In general, three different lithofacies are represented: (1) Woodford - Chattanooga - Percha - Houy Shales of Late Devonian and early Mississippian age, resting unconformably upon older Devonian carbonate strata or upon pre-Devonian rocks; (2) an older carbonate lithofacies, with varying amounts of chert, ranging in age from Lower to Middle Devonian, which in most areas rests unconformably upon Silurian, Ordovician or Cambro-Ordovician strata; (3) a novaculite lithofacies cropping out in the Ouachita Mountains of Arkansas and Oklahoma, and the Marathon region of West Texas; the age of this sequence is uncertain as fauna data are meager, but there may be strata representing Lower, Middle, and Upper Devonian. Devonian strata produce substantial quantities of oil or gas in parts of eastern Kansas, central Oklahoma, western Arkansas, and southwestern Texas.