NEW H-H’ CROSS SECTION FROM ALABAMA TO WEST VIRGINIA ILLUSTRATING THE REGIONAL STRUCTURAL AND STRATIGRAPHIC FRAMEWORK OF THE BLACK WARRIOR BASIN AND SOUTHERN AND CENTRAL APPALACHIAN BASIN

The U.S. Geological Survey (USGS) is creating a new geologic cross section extending from west-central Alabama to west-central West Virginia. It will be the sixth in a series of USGS Appalachian basin structural cross sections providing insight into the regional structural and stratigraphic framework of the Appalachian basin. The new cross section extends northeastward from the Black Warrior basin in Sumter County, Alabama, through the southern Appalachian basin of northern Alabama and eastern Tennessee, and the central Appalachian basin of eastern Kentucky and southern West Virginia, where it ends in Jackson County, West Virginia, a distance of 594 miles running parallel to the strike of the Appalachian Mountains. Three smaller cross sections running perpendicular to strike, and a fourth running parallel to strike, are also planned for locations in Sumter, Greene, Hale, Tuscaloosa, Bibb, Blount, and Saint Clair Counties in Alabama. Gamma ray and other well logs, core descriptions, and mud log records from 34 wells in Alabama, seven in Tennessee, nine in Kentucky, and three wells in West Virginia will be used to correlate stratigraphic units from well to well in these cross sections.

Major structural features exhibited in the new cross sections include: (1) bedding-plane detachment faults, associated thrust fault ramps, and the so-called “mushwad” structures (thick sequences of contorted weak shaley rocks overlying a regional decollement and underlying stiff roof rocks) in the Appalachian thrust fault zone of Alabama, (2) the Rome trough, a failed rift basin created by Middle Cambrian extension involving basement rocks bounded by normal faults in West Virginia and Kentucky, and (3) the deep subsurface Greene-Hale Synclinorium of Alabama where Devonian black shale may be a source of oil and (or) gas. USGS Appalachian basin cross-sections are widely used to provide framework geologic information for research into petroleum systems (including coal-bed methane in the Black Warrior basin and Devonian shale gas from the Chattanooga Shale and other formations), potential CO₂ storage in sandstone, salt, and carbonate formations, and fluid flow in the Appalachian basin.