The British Solomon Islands: Some Geological Implications of the Gravity Data, 1966

  1. Leon Knopoff,
  2. Charles L. Drake and
  3. Pembroke J. Hart
  1. J. C. Grover

Published Online: 18 MAR 2013

DOI: 10.1029/GM012p0296

The Crust and Upper Mantle of the Pacific Area

The Crust and Upper Mantle of the Pacific Area

How to Cite

Grover, J. C. (2012) The British Solomon Islands: Some Geological Implications of the Gravity Data, 1966, 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/GM012p0296

Author Information

  1. Department of Geological Surveys, Suva, Fiji Islands

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

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Keywords:

  • British Solomon Islands;
  • Gavity data;
  • Georgia group;
  • Guadalcanal and Choiseul;
  • Malaita;
  • Russell and Shortland Islands;
  • San Cristobal;
  • Savo volcano and Santa Isabel

Summary

During the land gravity expedition of 1963, gravity stations were established on coastlines and across the mountain ranges of the various larger islands of the Solomons. Most work was done on Guadalcanal. Some implications of the gravity maps are discussed from the point of view of the field geologist after a decade and a half of ground investigations. A remarkable correlation with deep seated geological features is apparent from the maps with Bouguer isogal intervals of 10 mgal. Higher values in higher country suggest that the ‘tectogenic' mountain building process does not apply. Major shears are suggested on Choiseul, Santa Isabel, and Guadalcanal. Tension features causing disruption of islands such as Florida, western Santa Isabel, and Savo are reflected by a change of direction in the isogals. Major faults on Guadalcanal, and discrete blocks such as San Cristobal, the two on Choiseul, and that of southeastern Guadalcanal show up well in the isogal maps. The mantle is probably much closer to the surface than the world average.