Geophysical study of permafrost drill core from Ross Island and Victoria Valley, Antarctica

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Geophysical study of permafrost drill core from Ross Island and Victoria Valley, Antarctica

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Resistivity measurements of crystalline basement rocks from Dry Valley Drilling Project (DVDP) 6 Lake Vida, show relative variation not indicated by surface electrical methods. The existence of a shallow, high resistivity zone observed by others is confirmed. Resistivity values up to 7 times normal can be correlated with geologically recognized sub-units in the upper 35m of the gneissic rocks. Below this depth, such variation is not seen. A resistive low is recognized around a basement fault of 88m. This fault is younger than the cataclasis of the gneissic rocks and the massive Vida Granite. P-wave seismic velocity data for the basement rocks in the shallow zone average 4.88km/sec, somewhat slower than velocity measurements further down hole. The highest velocities (6.34km/sec) measured in the core are found around 131m, and probably are caused by increased cataclasis of the basement gneiss. Resistivity measurements of ice-cemented pyroclastics of DVDP 3, Ross Island, Antarctica were also made. These data and published isotopic data on the waters suggest the presence of a fresh water zone to a depth of 290m below present sea level. Subglacial eruption and subsequent isostatic subsidence are proposed as a possible model foro the resistivity data.
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Masters thesis, Northern Illinois University
Bibliographic Citation: 
Jackson, J.K.Geophysical study of permafrost drill core from Ross Island and Victoria Valley, Antarctica-Thesis/DissertationMasters thesis, Northern Illinois University1975