Suggested Citation
Kerrigan, R. J., Shirley, Benjamin, and Wolff, Olivia, 2021, Petrogenesis and interactions of serpentinites intruded by pegmatite dikes, Unionville Serpentine Barrens, Chester County, Pennsylvania: Pennsylvania Geological Survey, 4th ser., General Geology Report 21–001.0, 19 p. plus appendix. [Available online.]
Description
The results of field mapping, sampling, and petrographic and geochemical analyses of the serpentinite, pegmatites, and contact aureoles in the Unionville Serpentine Barrens, southeastern Pennsylvania, is discussed in this report. It includes an appendix listing concentrations of major and trace elements in pegmatite, reaction-rock, and serpentinite samples. Geochemical analyses support the hypothesis that the serpentinite was originally the basement component of an island arc that collided with the eastern margin of North America about 450 million years ago. Trace elements plotted on granitic discrimination diagrams suggest that the source melt for the pegmatite intrusions was likely volcanic-arc granites or postcollisional granites.