MINERALOGY AND GEOCHEMISTRY OF THE ALLUVIUM IN THE FORTYMILE WASH REGION SOUTH OF YUCCA MOUNTAIN, NEVADA
As part of the independent oversight activities of the NRC, we conducted detailed studies of the mineralogy and chemistry of cuttings from two Nye County Early Warning Drilling Program (EWDP) wells. The wells, NC-EWDP-02D and NC-Washburn-1X, are located in the southern part of Fortymile Wash along the likely groundwater flow path from Yucca Mountain. The cuttings were analyzed using semi-quantitative XRD, thin section petrography, scanning electron microscopy, XRF, and ICP-MS. Results of analyses show that alluvium mineralogy does not change significantly at the water table. An increase in calcite and dolomite at depth in well NC-EWDP-02D is likely associated with the occurrence of sediments and sedimentary rocks that pre-date the tuff-derived alluvium. Zeolite and smectite minerals occur as grain coatings and interstitial material and may play an important role in alluvium retardation processes in Fortymile Wash.
This abstract was prepared to document work performed by the Center for Nuclear Waste Regulatory Analyses (CNWRA) for the NRC under Contract No. NRC-02-02-012. This abstract is an independent product of the CNWRA and does not necessarily reflect the view or regulatory position of the NRC.