Geochemical data from Ordovician and Silurian mafic rocks in the Wilmington Complex in Delaware, the James Run Formation in Cecil County, Maryland, and the Wissahickon Formation in Delaware and Pennsylvania were collected in conjunction with preparation of a new geologic map of the Delaware-Pennsylvania Piedmont. Although concentrations of most elements may have been disrupted by metamorphism, the more stable high field strength elements, including the rare earth elements (REE), are consistent within mapped lithodemic units and are compared to modern basaltic magmas from relatively well known tectonomagmatic environments.
Please give proper credit to the Delaware Geological Survey.
Plank, M.O., Srogi, L., Schenck, W.S., Plank, T.A., 2001, Geochemistry of the Mafic Rocks, Delaware Piedmont and Adjacent Pennsylvania and Maryland: Confirmation of Arc Affinity: Delaware Geological Survey Report of Investigation 60
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