Paleoecological Anatomy of a Conemaugh (Pennsylvanian) Marine Event

Abstract
Detailed paleoecological analysis of the Upper Pennsylvanian Ames limestone and shale near Morgantown, West Virginia, suggests that the Ames transgression in that area was very rapid, presumably over a low-relief plain. Evidence of stillstand is in a lower Ames shale sequence immediately overlying the Harlem coal and, thus, is at odds with traditional interpretations which have placed stillstands in the limestone units of cyclothems. This interpretation is based upon a faunal analysis that resulted in the subdivision of the total Ames marine sequence into five communities: a basal stable mature community with maximum faunal diversity (stillstand); three distinct, and probably laterally adjacent, relict mature communities (regression); and an upper “mixed” community in the final regressive phase of the Ames marine event. The latter might be an assemblage, rather than a reflection of a once living community.