Upper Cretaceous fossil beach placers of Wyoming

Most of the beach placer deposits in Wyoming are in the Campanian Mesaverde Formation, although minor deposits are also known in the Cenomanian–Turonian Frontier Formation, Campanian–Maastrichtian Lewis Shale, and Maastrichtian Fox Hills Sandstone. Some Cretaceous paleoplacers in Wyoming have been previously investigated as sources of titanium (Houston and Murphy, 1962), but pre-existing datasets provide only limited insight as to potential of these deposits as a source of other critical minerals. 

With the goal of expanding the public geochemical dataset for these deposits, whole-rock geochemical measurements were conducted on 177 samples from 30 known or suspected Mesozoic paleoplacers throughout the state. Additionally, the mineralogy of select samples was examined with optical petrographic microscopy, scanning-electron microscopy (SEM), and X-ray diffraction (XRD).