Hon, R., J. P. Fitzgerald, S. L. Sergent, W. D. Schwartz, J. Dostal, and J. D. Keppie. 1992. “Silurian-Early Devonian Mafic Rocks of the Piscataquis Volcanic Belt in Northern Maine”. Atlantic Geoscience 28 (2). https://doi.org/10.4138/1858.