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Title: Tyrone-Mt. Union cross-strike lineament of Pennsylvania: a major Paleozoic basement fracture and uplift boundary

Conference · · Am. Assoc. Pet. Geol., Bull.; (United States)
OSTI ID:6726344

The Tyrone-Mt. Union lineament of central Pennsylvania is one of many lineaments recognized in the Appalachian Valley and Ridge province. This feature has been projected into the Plateau province where it defines a cross-strike structural discontinuity. Geomorphic evidence of the lineament is recorded in Mississippian and older rocks. Near-surface hydrocarbon measurments, reservoir gas analysis, fracture measurements, borehole surveys, and very low-frequency electromagnetic data indicate that these lineaments are zones of increased fracture permeability with enhanced hydrocarbon and fluid migration. In one gas field, wells drilled along the lineament had significant gas shows in organic-rich Devonian shales. Several Devonian through Early Pennsylvanian formations are characterized by facies and thickness variations across this lineament. These data consistently suggest that the lineament marks the southern boundary of an uplift in north-central Pennsylvania. This uplift boundary is recognized in northwestern Pennsylvania in surface and subsurface data. Farther southeast, where Allegheny deformation was stronger, this subtle boundary is obscured. Analysis of subsurface data suggests that this uplift has affected fold terminations and structural elevations in the vicinity of the lineament. The structural and stratigraphic anomalies recognized in this study overlie a crustal-block boundary. These trends may be explained by differential subsidence of these crustal blocks. 16 figures 2 tables.

Research Organization:
Univ. of Pittsburgh, PA
OSTI ID:
6726344
Journal Information:
Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 68:1; Conference: American Association of Petroleum Geologists Southwest Section Meeting, Midland, TX, 5 Feb 1984
Country of Publication:
United States
Language:
English