Detailed Surface Structure Starting Point for Understanding Deep Appalachian Geology

Philip L. Martin
Bridgeport, WV; [email protected]

Many continuous bench-forming sandstones of the Permian(?), Pennsylvanian, Mississippian, and Upper Devonian formations exposed at the surface in the Appalachian Plateau lend themselves very well to accurate stereo-tracing on aerial photos. The penciled traces of these units are accurately posted from the photos to USGS 7.5’ Topographic Maps, where the many intersections of these traces with topographic contours provide a myriad of elevation control points on any selected datum unit. Interval-conversion from the datum to other traces above and below expands control beyond the outcrop area of the datum. This elevation control is then contoured to produce surface structure maps which reveal many previously unmapped features and structural relationships.

The diligent and on-going application of this mapping technique in the Appalachian Plateau of Western Pennsylvania has produced very detailed surface structure maps of ninety one 7.5’ Quads so far, covering an area from Cameron, Clinton, and Lycoming Counties in the north to Fayette, Somerset, and Bedford Counties in the south. The structure contours, faults, and fold axes, plus political boundaries, have been digitized and can be layered in with seismic, isopach, production, and other maps. Such a display often reveals surprising relationships between subsurface geology and surface structure. “Look-alike” surface anomalies in areas of no subsurface control then can become prospective exploration or extension targets.

All maps also are available as scanned images on CD’s in tif format, or as color or black and white prints. Also, all maps are protected by Copyright.

Presented AAPG Eastern Section Meeting, Pittsburgh, Pennsylvania 2008 © AAPG Eastern Section