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Precambrian Basement Provinces Map - U.S.

Detailed Description

Map showing Precambrian basement provinces of the United States and location of St. Francois Mountains terrane in southeast Missouri. Neodymium (Nd) line separates basement rocks with Nd model ages greater than (northwest side) and less than (southeast side) 1.6 Ga. Modified from Bickford et al. (2015).


Public Domain.