The Transition from Ocean to Continent From Seismic Refraction Data

  1. Leon Knopoff,
  2. Charles L. Drake and
  3. Pembroke J. Hart
  1. Charles L. Drake and
  2. John E. Nafe

Published Online: 18 MAR 2013

DOI: 10.1029/GM012p0174

The Crust and Upper Mantle of the Pacific Area

The Crust and Upper Mantle of the Pacific Area

How to Cite

Drake, C. L. and Nafe, J. E. (2012) The Transition from Ocean to Continent From Seismic Refraction Data, in The Crust and Upper Mantle of the Pacific Area (eds L. Knopoff, C. L. Drake and P. J. Hart), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM012p0174

Author Information

  1. Lamont Geological Observatory, Columbia University, Palisades, New York

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 20 APR 2012

Book Series:

  1. Geophysical Monograph Series

Book Series Editors:

  1. Waldo E. Smith

ISBN Information

Print ISBN: 9780875900124

Online ISBN: 9781118663738

SEARCH

Keywords:

  • Atlantic data;
  • Caribbean and Mediterranean Seas;
  • Crystalline rock;
  • Mexico and Somali basins;
  • Oceanic islands;
  • Seismic compressional velocity vs. depth beneath;
  • Seismic refraction data;
  • Velocity-depth data

Summary

Seismic refraction data from oceans and continents have been examined to see whether they are related in any systematic way to geological structures or provinces. A series of broadly defined provinces, related in general to topography, has been established, and the seismic compressional velocities determined by refraction measurements have been plotted as a function of depth. As might be expected, the narrowest range of seismic properties is found in the ocean basins and beneath the stable, low-lying Precambrian shields, while the greatest variability is found under the young orogenic belts. If one accepts that ancient and more recent orogenic activities are controlled by the same mechanism, then there is an indication that material in the velocity range 7.2–7.7 km/sec may be of a transient nature and may appear and then disappear during the orogenic history of a given region. The data also suggest that oceanic crust might be converted to continental crust, but do not support the reverse process.