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U.S. Department of Energy
Office of Scientific and Technical Information

Low frequency electromagnetic prospecting system. [Grass Valley, KGRA]

Technical Report ·
DOI:https://doi.org/10.2172/6771904· OSTI ID:6771904
A prototype portable electromagnetic sounding system was assembled and depth sounding survey was conducted in Grass Valley, Nevada, as a part of a program to evaluate geophysical techniques in geothermal exploration. A horizontal loop transmitter of radius 50 meters operating between .01 Hz and 100 Hz was used in conjunction with a SQUID magnetometer. A digital synchronous detector was used for on site processing of magnetometer output. This detector allowed useful data acquisition with transmitter-receiver separation of up to 2 km with power requirements of less than 72 watts. Conductive sediments (1 to 10 ohm-m) of thicknesses of up to 1.5 km were well resolved with this system, and the interpreted sections compared very well with dc resistivity measurements made with much heavier equipment and larger arrays in the same area.
Research Organization:
California Univ., Berkeley (USA). Lawrence Berkeley Lab.
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
6771904
Report Number(s):
LBL-7042
Country of Publication:
United States
Language:
English