DEPOSIT IONAL ENVIRONMENT OF THE SHARON CONGLOMERATE MEMBER OF THE POTTSVILLE FORMATION IN NORTHEASTERN OHIO 1

ABSTRACT: The Sharon Conglomerate in northeastern Ohio, a member of the Pottsville Formation (Pennsylvanian), is a sheetlike deposit filling the highly dissected, erosional su~rfaee developed on underlying Mississippian strata. It consists generally of poorly cemented, medium-grained quartzarenite with the majority of conglomerate occurring in at least two north-south trending channels. Shales and siltstones occur as thin beds or lenses in only a few outcrops. An examination of primary sedimentary structures and textures and their vertical and lateral relationships was made to determine the environment of deposition of the Sharon. Sandstones are predominantly planar cross-bedded with trough cross-bedding common and horizontal bedding rare. The channel conglomerates exhibit massive, horizontal, planar, and trough cross-bedding with horizontal and planar cross-bedding being the dominant types. There is no apparent orderly sequence of bedding types or textures in either vertical or horizontal sections in the sandstones or cong]omerates. Based on lithology, geometry, an( [ abundance of planar cross-stratification, the Sharon Conglomerate is interpreted as an alluvial plain deposit formed by braided streams. The conglomerates probably represent deposits in the thalwegs of streams that carried the main thread of current during periods of high discharge and possibly the entire flow during periods of low discharge. Cross-bedding dip azimnths indicate a northern source area for the Sharon Conglomerate