Moho Reflections from the Long Island Platform, Eastern United States

  1. Muawia Barazangi and
  2. Larry Brown
  1. D. R. Hutchinson2,
  2. J. A. Grow3,
  3. K. D. Klitgord1 and
  4. R. S. Detrick2

Published Online: 15 MAR 2013

DOI: 10.1029/GD014p0173

Reflection Seismology: The Continental Crust

Reflection Seismology: The Continental Crust

How to Cite

Hutchinson, D. R., Grow, J. A., Klitgord, K. D. and Detrick, R. S. (1986) Moho Reflections from the Long Island Platform, Eastern United States, in Reflection Seismology: The Continental Crust (eds M. Barazangi and L. Brown), American Geophysical Union, Washington, D. C.. doi: 10.1029/GD014p0173

Author Information

  1. 1

    U.S. Geological Survey, Woods Hole, Mass. 02543

  2. 2

    Graduate School of Oceanography, U.R.I., Kingston, R.I., 02882

  3. 3

    U.S. Geological Survey, Denver, Colorado 80225

Publication History

  1. Published Online: 15 MAR 2013
  2. Published Print: 1 JAN 1986

Book Series:

  1. Geodynamics Series

ISBN Information

Print ISBN: 9780875905143

Online ISBN: 9781118670118

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Keywords:

  • Earth—Crust—Congresses;
  • Continents—Congresses;
  • Seismic reflection method—Congresses

Summary

Strong reflections from 9.5–12 s depth (two-way travel time), which were recorded on a grid of seismic-reflection profiles on the Long Island platform of the U.S. Atlantic continental margin, are interpreted as reflections from the Mohorovicic discontinuity. The character of the reflection is generally sharp although some laminations occur to the east. The southerly dip of the Moho surface is explained by the effects of thickening low-velocity sediment and water layers. A region of lower travel times east of the Long Island rift basin may be crust that was thinned during Mesozoic rifting. A region of apparent crustal thickening in the central platform may have been relatively unaffected by Mesozoic extension. Travel times through the crust (excluding sediments and water) decrease towards the basement hinge zone, in agreement with theories of crustal thinning across passive continental margins. The velocity of the crust beneath the platform is not well enough known to permit accurate conversion of the time-sections to depth or migration of the deep events.