Major, cross-strike structural discontinuities appear to be large volumes of intensely fractured rock, and may be useful guides in exploration for fractured gas reservoirs. To determine whether the Petersburg lineament of the western Valley and Ridge province of West Virginia is expressed in the Pennsylvanian rocks of the easternmost Plateau province, LaCaze mapped about 60 square km (23 square m) of late Paleozoic molasses atop Allegheny Front, in an area straddling the lineament's westward projection. Eight outcrops of Homewood sandstone strung across the projection contain longitudinal, transverse and an east-striking set of diagonal joints. Joint intensity (surface area per unit volume of rock) in the projection is about twice that outside. Structure contours show that a map-scale syncline is disrupted immediately west of the high-intensity zone. Thus the lineament is expressed in the Pennsylvanian rocks of the easternmost Plateau province as a zone of increased fracturing at least 1.3 km (0.18 m) wide, with associated broader disruption of map-scale structure.