.0 REFERENCES Berggren, W.A., 1972, A Cenozoic time-scale--some implications for regional geology and paleobiogeography: Lethia, v. 5, no. 2, p. 195-215. Boyer, R.E., 1962, Petrology and structure of the southern Wet Mountains, Colorado: Geol. Soc. America Bull., v. 73, no. 9, p. 1047-1070. Chronic, B.J., Jr., 1958, Pennsylvanian rocks in central Colorado, in Rocky Mt. Assoc. Geologists, Symposium on Pennsylvanian rocks of Colorado and adjacent areas, p. 59-63.