Abstract: A Fresh Look at Bass Islands through Bois Blanc Distributions Structure, and Trap Potential, Erie County, Pennsylvania

John P. Hobson Jr., Samuel T. Pees

Subsurface Upper Silurian and Lower Devonian strata have been correlated and mapped through a 55 sq. mi (143 sq. km) area of dense well control in Waterford and LeBoeuf Townships. Mapped strata include the Bass Islands. Helderberg, Oriskany and Bois Blanc Formations and parts of the Salina Group. Critical lithologic and paleontologic data have been obtained from the only core of the Lower Devonian in Erie County.

Structure in the area is dominated by an asymmetrical SSE-plunging anticlinal nose. Structure on formations above the Salina "B" is influenced by lateral thickness variation of Salina "B" salt and consequent effects on thickness of the Oriskany and Bois Blanc Formations. The latter thicken in areas where "B" salt is absent.

In most of LeBoeuf Township the Oriskany and Helderberg are absent and the Bois Blanc rests directly by unconformity on Bass Islands dolomite. In Waterford Township the Oriskany and Helderberg are generally present below pre-Bois Blanc and pre-Oriskany unconformities.

Structural closure on the nose in Bois Blanc and Oriskany sandstones is provided by the combination of structural and stratigraphic factors and good gas shows have been tested from the formations.

AAPG Search and Discovery Article #90954©1995 AAPG Eastern Section, Schenectady, New York