The seismometer, located in White Clay Creek State Park, is positioned on the Wissahickon Formation. The Wissahickon Formation is an extensive sequence of pelitic and psammitic gneisses interlayered with amphibolites. With few exceptions, most of the amphibolite layers are less than 30 feet thick. The rocks have been metamorphosed to upper amphibolite facies and isoclinally folded.
The formation is located within the Wilmington North, Kennett Square, West Grove, Newark West, and Newark East U. S. Geological Survey 7.5-minute quadrangles.
Seismometer:Teledyne Geotech S-13 Short period Vertical
Amplifier: Emtel 6243 Gain 24dB
VCO: 2380 Hz
Elevation: 90 meters above sea level