Crustal Deformation and Igneous Activity in the South Fossa Magna, Japan
- Gordon A. Macdonald and
- Hisashi Kuno
Published Online: 21 MAR 2013
Copyright 1962 by the American Geophysical Union.
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
- Published Online: 21 MAR 2013
- Published Print: 1 JAN 1962
Book Series Editors:
- Waldo E. Smith
Print ISBN: 9780875900063
Online ISBN: 9781118669310
- Crustal deformation;
- Fossa Magna region;
- Igneous activity in the South Fossa Magna;
- Tectonic development;
- Volcanic rocks
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.