Maps showing monazite and xenotime content in the Atlantic coastal plain.

Maps showing monazite (left) and xenotime (right) content in coastal plain NURE and NGS estimated using the La concentration in monazite and the Yb concentration in xenotime, after correcting for monazite- and zircon-hosted Yb. For reference, mapped exposures of Cretaceous, Paleogene and Quaternary sediments are identified, but limestone and calcareous units are omitted. The monazite belts identified by Mertie (1953) are shown as dark polygons interior to the coastal plains. Note that no samples exist in southwestern Tennessee in the NURE database and NGS samples for that region lack INAA data. Modified from Figure 8, Bern and others, 2016, doi:10.1016/j.gexplo.2015.12.011.