Refractory clay deposits of south-central Colorado /
Waagé, Karl M.(Karl Mensch),1915-
Washington, [D.C.] : U.S. G.P.O.,
1953.
Five folded maps in pocket.
"A description of the refractory and semirefractory clays in the Purgatoire formation and Dakota sandstone."
Bibliography: p. 93-94.
Clay
Geology, Stratigraphic
Geology