PROVENANCE OF THE BINNEWATER SANDSTONE (SILURIAN), ROSENDALE, NY

The investigators have conducted preliminary research on the Silurian Binnewater Formation, outcropping in Rosendale, N. Y. The Upper Silurian Binnewater Sandstone is variable in composition. Several primary sedimentary structures including asymmetrical ripple marks, gently dipping cross-bedding and mud cracks were observed in the field. These have significant sedimentological importance in terms of determining depositional environments and direction of sediment transport (paleocurrent direction). The research includes detailed field investigation, sample collection and laboratory work at York College (CUNY). Preliminary field and laboratory work indicate the presence of the following heavy minerals: zircon, tourmaline, garnet, rutile, and opaques (possibly iron oxides). The light mineral fractions are predominantly; monocrystalline and polycrystalline quartz, muscovite, feldspar (mostly k-spar) and rarely biotite. The mixed mineral assemblage, including metamorphic and/or igneous minerals, suggests a mixed provenance. Bimodal distributions of tourmaline and zircon (ZTR Index) indicate some recycling or reworking of previously deposited material. There is a consistent pattern in the overall grain size distribution of the sand, a coarsening upward within the formation. It appears typical of a fluvial to deltaic environment. In the study area, the thickness of the Binnewater Sandstone varies from about 10 to 20 feet, perhaps due to variable rate of sedimentation with time or possible post depositional erosion.