ELEMENTAL AND MINERALOGICAL VARIATION IN THE UPPER SILURIAN TO LOWER DEVONIAN FORMATIONS IN ROSENDALE, ULSTER COUNTY, NEW YORK, USA

The town of Rosendale area of southeastern New York is worldwide known as the home for the superior quality natural cement in North America where the North American natural cement industry sustained for over 150 years. The highest quality natural cements originates from the mines in the low northeast-trending hills of the Rosendale region. The excellent bedrock exposures within the mines of the Rosendale region also attracted the attention of numerous nationwide geoscientists to explore the complex sedimentary structures and geochemistry of the different rock units. The formations in the Rosendale area range from Ordovician to Devonian in age. Limestone, Shale, Conglomerate and Sandstone are the major types of sedimentary rocks in our study area. The Acadian and Taconic orogenies resulted in deformation of the units in this area. Dolostone from the Rosendale and Whiteport members of the Upper Silurian Rondout Formation was used in the production of natural cement. The oldest geologic unit exposed near Rosendale is the Middle Ordovician Martinsburg Formation, locally known as Hudson River shale and the youngest one is the Esopus shale formation . Each formation has its own unique characteristics and details that indicate the different depositional environment. The area had gone through two orogenies and is filled with fault, fold, lineation. The thickness of the formation varied from place to place. The study aims to explore the elemental variation and mineralogy of the different units by using handheld XRF (x-ray Fluorescence spectrometer). Elements such as Ca, K, Sr, Rb, Zr and Fe can shed light on different paleo-environment under which the formations were formed. Cd, Cr, Se, Zn, As, Hg, Ba, and Pb are contaminants, if present in the formations these can leach into the surrounding water system making it unfit for human consumption.