Geophysical study of Cenozoic rocks from the McMurdo Sound region, Antarctica

• Main Author: Laymon, Douglas E. (Douglas Eugene).
• Other Authors: Ervin, C. Patrick, Department of Geology
• Format: Thesis
• Language: English
• Published: Northern Illinois University 1986
• Subjects: Geophysics > Antarctica; Petrology > Antarctica; McMurdo Sound; Ross Island; Taylor Valley; Wright Valley; Brown Peninsula; Meserve Glacier; Sollas Glacier; Antarc*; Antarctica
• Online Access: http://commons.lib.niu.edu/handle/10843/16239

Bibliography: pages [53]-57. Magnetic profiles across three volcanic cones are modeled. These are located in Taylor Valley near Sollas Glacier, near the mouth of Wright valley, and in Wright Valley near Meserve Glacier. The Sollas Glacier profile shows a polarity reversal, with a negative anomaly of about 1400 gammas. The profile near Meserve Glacier has both normal and reverse polarizations. The Meserve model also suggests the location of feeders of both events. Polarization direction is determined for four oriented samples of the McMurdo volcanics. One sample from the Meserve site shows a probable reversal, and two samples from Taylor Valley area show normal orientation. The fourth sample, taken from the Meserve site, gives inconclusive results. Magnetic susceptibility, density and compressional wave velocities are determined for 47 hand samples from the McMurdo Sound region. The samples consist of McMurdo Volcanics, of Cenozoic sediments, and of lower crustal xenoliths found in the volcanics. For 38 more samples of the McMurdo Volcanics, only the magnetic susceptibility is measured. The volcanic samples were all taken from the vicinity of Wright and Taylor Valleys. The densities of the volcanic samples range from 1.86 to 3.02 g/cc, the velocity values range from 1940 to 4840 m/sec, and the susceptibility values range from .0002 to .008 c.g.s. units. The Cenozoic sediment samples were taken from the mouth of Taylor Valley, from the Strand Moraine, from Mt. Discovery, and from Brown Peninsula, where they occur as glacial erratics. The densities range from 1.98 to 2.79 g/cc. The velocities vary from 1024 to 4866 m/sec and the susceptibilities vary from .000008 to .0025 in c.g.s. units. The xenoliths were obtained from volcanic cones found on Ross Island and in the Dry Valleys region. The densities of the xenoliths range from 2.52 to 3.05 g/cm. The velocities for the xenoliths are very low, probably due to the presence of microfractures. The susceptibilities range from .00003 to .00018 c.g.s. units. M.S. (Master of Science)