GEOCHEMICAL INVESTIGATION OF THE HUDSON RIVER SHALE, ROSENDALE, NEW YORK

The Hudson River shale (HRS) is a dark grey to black shale of Ordovician age, which is believed to correlate to the Martinsburg Shale (MS) which is found to the southwest. Investigation of the HRS is being conducted to see if the data support correlation with the MS. The data collected were compared with known data regarding the MS as well as the North American Shale Composite (NASC). In Rosendale, NY two outcrops of the HRS, just below the angular unconformity with the Lower Silurian High Falls shale, have been observed at N41 52 .392 , W74 04 .395 , N41 51 .923 and W74 04 .770 respectively. While both outcrops contain some fossils, the outcrop located at N41 51 .923 and W74 04 .770 is extremely fossiliferous, with numerous brachiopods and crinoids of uncertain age. Field investigation of the fossiliferous zones revealed that they are calcareous. X-Ray Fluorescence (XRF) examinations of the outcrops in question were also conducted in the field and in the laboratory. Preliminary evaluation of the data reveals elements that are consistent with the depositional environment of shale, particularly Cu, Zn, Mn, Sr, Ba, Rb, and Pb. Analysis of bulk oxides including silica, alumina, potash, soda, and magnesia, showed a rough correlation among the HRS, MS, and NASC. Identification of the fossils found within this formation (HRS) will be conducted to further investigate evidence of correlation between the HRS and the MS.