Crustal Extension in the Midcontinent Rift System—Results from Glimpce Deep Seismic Reflection Profiles Over Lakes Superior and Michigan

  1. Robert F. Mereu,
  2. Stephan Mueller and
  3. David M. Fountain
  1. J. C. Behrendt1,
  2. A. G. Green2,
  3. M. W. Lee1,
  4. D. R. Hutchinson3,
  5. W. F. Canon4,
  6. B. Milkereit2,
  7. W. F. Agena1 and
  8. C. Spencer2

Published Online: 9 APR 2013

DOI: 10.1029/GM051p0081

Properties and Processes of Earth's Lower Crust

Properties and Processes of Earth's Lower Crust

How to Cite

Behrendt, J. C., Green, A. G., Lee, M. W., Hutchinson, D. R., Canon, W. F., Milkereit, B., Agena, W. F. and Spencer, C. (1989) Crustal Extension in the Midcontinent Rift System—Results from Glimpce Deep Seismic Reflection Profiles Over Lakes Superior and Michigan, in Properties and Processes of Earth's Lower Crust (eds R. F. Mereu, S. Mueller and D. M. Fountain), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM051p0081

Author Information

  1. 1

    U.S. Geological Survey, Denver Federal Center, Denver, Co

  2. 2

    Geological Survey of Canada, 1 Observatory Cresc., Ottawa, Ont. Canada

  3. 3

    U.S. Geological Survey, Woods Hole, Ma

  4. 4

    U.S. Geological Survey National Center, Reston, Virginia

Publication History

  1. Published Online: 9 APR 2013
  2. Published Print: 1 JAN 1989

ISBN Information

Print ISBN: 9780875904566

Online ISBN: 9781118666388

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Keywords:

  • Earth—Crust—Congresses;
  • Geophysics—Congresses

Summary

As part of the Great Lakes International Multidisciplinary Program on Crustal Evolution (GLIMPCE) the United States Geological Survey and the Geological Survey of Canada have collected about 700 km of 120-channel deep seismic reflection data across the Midcontinent (Keweenawan, 1.1 Ga) Rift system in Lakes Superior and Michigan. Results published by Behrendt et al. [1988] showed that volcanic and interbedded sediments of the rift extend to depths as great as about 32 km (10.5 s reflection time) beneath parts of Lake Superior, suggesting that this area may overlie the greatest thickness of intracratonic rift deposits on Earth. Times to Moho reflections vary from 11.5 s to 17 s (about 37–55 km depth) along the rift in Lake Superior and northern Lake Michigan. Additional GLIMPCE seismic reflection sections crossing the Midcontinent Rift system are presented here. We propose an interpretation to account for the substantial magmatic additions to the extended crust demonstrated by our data.