Paleomagnetic Results from the Kirkpatrick Basalt Group, Mesa Range, North Victoria Land, Antarctica

  1. Edmund Stump
  1. William C. Mcintosh1,
  2. Philip R. Kyle1 and
  3. John F. Sutter2

Published Online: 16 MAR 2013

DOI: 10.1002/9781118664957.ch14

Geological Investigations in Northern Victoria Land

Geological Investigations in Northern Victoria Land

How to Cite

Mcintosh, W. C., Kyle, P. R. and Sutter, J. F. (1986) Paleomagnetic Results from the Kirkpatrick Basalt Group, Mesa Range, North Victoria Land, Antarctica, in Geological Investigations in Northern Victoria Land (ed E. Stump), American Geophysical Union, Washington, D. C.. doi: 10.1002/9781118664957.ch14

Author Information

  1. 1

    Department of Geosciences, New Mexico Institute Of Mining and Technology, Socorro, New Mexico 87801

  2. 2

    U.S. Geological Survey, Reston, Virginia 22092

Publication History

  1. Published Online: 16 MAR 2013
  2. Published Print: 1 JAN 1986

ISBN Information

Print ISBN: 9780875901978

Online ISBN: 9781118664957

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Keywords:

  • Geology—Antarctic regions—Victoria Land

Summary

Sixty samples from 15 Jurassic Kirkpatrick Basalt Group flows in the Mesa Range, north Victoria Land, were studied paleomagnetically using alternating field (AF) and thermal demagnetization. The magnetic mineralogy was examined using reflected light microscopy and thermomagnetic analysis. 40Ar/39Ar age determinations were attempted on two samples. One of these yielded an age of 174.2±1.0 Ma. All of the samples show strong, stable, normal remanence interpreted as a primary thermoremanent magnetization (TRM) carried by titanomagnetite. Components of secondary remanence were found to be minor. Small components of viscous magnetization were readily removed by AF demagnetization in fields of 20 mT. Samples from 14 flows are free from components of chemical remanent magnetization (CRM); samples from the fifteenth flow exhibit a minor CRM component in a reversed direction. The mean virtual geomagnetic pole (VGP) of the Mesa Range samples (64°S, 210°E, dP = 4.2° , dM = 4.4°) lies significantly south of the mean paleomagnetic pole (54.3°S, 220.9°E, dP = 4.5°, dM = 5.0°) reported from Jurassic rocks elsewhere in Antarctica. This discrepancy is apparently unrelated to tectonic motions or secondary remagnetization. It appears that the 15 sampled flows are too few to have completely averaged paleosecular variation. This conclusion is supported by limited data from two sites in dolerite sills at Section Peak, 20 km west of the Mesa Range.