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Delineation Of The Fractured-Rock And Unconsolidated Overburden Ground-Water Flow Systems, On The Southern Part Of Manhattan, New York, Through Use Of Advanced Borehole-Geophysical Techniques, Frederick Stumm

Dissertations, Theses, and Capstone Projects

Advanced borehole-geophysical techniques were used to assess the geohydrology of crystalline bedrock in 31 of 64 boreholes on the southern part of Manhattan Island, N.Y. Ten wells were screened in the unconsolidated overburden (glacial aquifer) to determine water-table elevation, transmissivity, and chloride concentration. The borehole-logging techniques included natural gamma, single-point resistance, short-normal resistivity, mechanical and acoustic caliper, magnetic susceptibility, borehole-fluid temperature and resistivity, borehole-fluid specific conductance, dissolved oxygen, pH, redox, heat-pulse flowmeter (at selected boreholes), borehole deviation, acoustic and optical televiewer, and borehole radar (at selected boreholes). The boreholes penetrated gneiss, schist, and other crystalline bedrock that has an overall …