SEISMIC REFLECTION PROFILE OF SOUTH-CENTRAL PENNSYLVANIA: LEBANON AND LANCASTER COUNTIES

A 40 mile long seismic reflection line was run from northern Lebanon County to the Mason-Dixon line in Lancaster County. The Pennsylvania Bureau of Topographic and Geologic Survey contracted for the survey as part of an investigation into the suitability of the entire state of Pennsylvania for carbon sequestration (Carbon Sequestration Technical Assessment [CSTA]). The Vibroseis and Accelerated Weight Drop (AWD) sourced line was collected in three sections: a northern line with the AWD source, a Vibroseis southern line, and a duplicate line over the Triassic basin using both sources. The data were recorded for 6 seconds. There being no deep wells in the region, it was not possible to create a reliable velocity profile. This was the first such line ever run in this region and will likely be the last as development is rapidly making it difficult to acquire data.

The northern line showed complex faulting in thick carbonates. The location of the line had been chosen to find the quietest route through the region and the route resulted in crossing the Triassic basin at a very narrow and shallow zone. The Triassic basin was not clearly discernible. The southern line showed a very large thrust fault which climbed from several miles down at the southern end, reaching the surface south of the Martic Line. This may correspond to a previously mapped feature.