Geological structure beneath Tokyo Bay analysed by multi-channel seismic reflection survey in 1983.
A thirteen lines multi channel seismic reflection survey in Tokyo Bay was carried out by the Hydrographic Department in October 1983, to follow up on a survey in 1981 to 1982 to clarify the geologic structure to about 3 km depth (Kato, 1984). From analysis of 12 fold stack sections along these lines, we were able to make some new interpretations of the stratigraphy at shallow depth below the sea bottom. The uppermost part of the subsurface geology, called”TA” and corresponding to the Shimosa Group of the Middle Pleistocene in the Boso Peninsula, represents distinct alternations of dark and light colored beds. Eight or nine sets of beds are present and each seems to represent a sedimentary cycle related to glacio-eustatic transgression. The basal boundary of ”TA” is a remarkable unconformity called the Tokyo Bay unconformity. A gentle dome like structure appears under the Nakanose Bank, around the south end of the Bay. It is supposed that the bank was affected by upwarping tectonics.
| Main Authors: | , |
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| Format: | Journal Contribution biblioteca |
| Language: | Japanese |
| Published: |
1991
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| Online Access: | http://hdl.handle.net/1834/16098 |
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