Crustal Deformation and Igneous Activity in the South Fossa Magna, Japan

  1. Gordon A. Macdonald and
  2. Hisashi Kuno
  1. Tokihiko Matsuda

Published Online: 21 MAR 2013

DOI: 10.1029/GM006p0140

The Crust of the Pacific Basin

The Crust of the Pacific Basin

How to Cite

Matsuda, T. (1962) Crustal Deformation and Igneous Activity in the South Fossa Magna, Japan, in The Crust of the Pacific Basin (eds G. A. Macdonald and H. Kuno), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM006p0140

Author Information

  1. Earthquake Research Institute, University of Tokyo, Tokyo, Japan

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1962

Book Series:

  1. Geophysical Monograph Series

Book Series Editors:

  1. Waldo E. Smith

ISBN Information

Print ISBN: 9780875900063

Online ISBN: 9781118669310

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Keywords:

  • Crustal deformation;
  • Fossa Magna region;
  • Igneous activity in the South Fossa Magna;
  • Tectonic development;
  • Volcanic rocks

Summary

A remarkable correspondence between the type of crustal deformation and the type of igneous activity is shown in the South Fossa Magna, a Tertiary geosyncline lying on the Pacific border of central Japan.

The geologic history in early Miocene time was as follows: (a) regional subsidence of the crust, the subsidence exceeding several kilometers; (b) contemporaneous eruption of tholeiite and alkaline basalt magmas, the volume of these eruptions exceeding 20,000 km3.

During later Miocene time, the geologic history was: (a) Deformation of the crust into folds with two different orders of wavelength. The broader folds divided the former basin into belts of uplift and subsidence, each about 20 km in wavelength and more than 5 km in amplitude; the narrower folds divided these belts into synclines and anticlines with wavelengths of 3 to 5 km. (b) Contemporaneous intrusion and eruption of calc-alkaline magma, the intrusion of quartz diorite into the core of the uplifted belts, and the local eruption of calc-alkaline andesite.

During Pliocene and Pleistocene time the area suffered strong compression, which formed imbricate structures with repeated broken folds and thrusts. There was very little volcanic activity at this time. In the relatively stable area (the Izu platform), on the other hand, block movements and active volcanism have prevailed since middle Miocene time.