Abstract
Electrical resistivity measurements of the sea bed have been made from the submersible Cyana at four locations on a seamount close to the axis of the East Pacific Rise. Two of the sites were on a major sulpide deposit close to the top of the seamount, and the other two on pillow basalts near its base. The resistivity of the pillow-lava terrain was found to be about forty times greater than that of the sea water, in good agreement with downhole logging measurements in DSDP drill holes. The resistivity of the sulphide bottom was one to two orders of magnitude less than that of the pillow basalts. At one site the sea bed was almost twice as conductive as the overlying sea water and the deposit at this location is estimated to be about 9 m thick.
Self-potentials of up to 10 mV, measured between a pair of electrodes 10 m apart, were associated with the sulphide deposit but were undetectable (i.e.≤0.1 mV) on the pillow basalts. The largest SP was associated with the most conductive sea bed, i.e. with the greatest concentration of sulphides.
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Francis, T.J.G. Resistivity measurements of an ocean floor sulphide mineral deposit from the submersible Cyana. Mar Geophys Res 7, 419–437 (1985). https://doi.org/10.1007/BF00316778
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DOI: https://doi.org/10.1007/BF00316778