Stratotype of Ordovician Whiterock Series

Abstract

Here the authors reaffirm and document fossil ranges at the stratotype section for the base of the Whiterock Series in Whiterock Canyon, northern Monitor Range, Nevada, and designate a reference section at Meiklejohn Peak, Bare Mountain quadrangle, Nevada. In both sections, stratigraphic ranges of conodonts indicate that the boundary between the Whiterock and the underlying Ibex Series lies between Oepikodus evae below and Tripodus laevis above. This level is correlated with the inception of the Isograptus victoriae graptolite lineage. Coeval brachiopod and trilobite faunas are summarized and their ranges graphically illustrated. The base of the Whiterock Series seems to be coincident with the start of the Taconic Orogeny. During the Whiterock other tectonically controlled events preceded the Tippecanoe Sequence in North America.