1994 Fiscal Year Final Research Report Summary
Sequence model in forearc basin setting
| Project/Area Number |
05640493
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Geology
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| Research Institution | Chiba University |
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Principal Investigator |
ITO Makoto Department of Earth Sciences, Chiba University Associate Professor, 理学部, 助教授 (10201930)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Sequence stratigraphy / Kazusa Group / Shimosa Group / Forearc basin / Glacio-eustasy |
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| Research Abstract |
Variations in geometry, lithofacies organization and detrital composition of depositional sequences developed in a forearc basin setting have been investigated in terms of the interaction between forearc tectonics and eustasy. In general, forearc basins are characterized by narrow shelves and active supply of coarse-grained terrigenous sediments to a marine environment, associated with higher rate of tectonic movements and supply of pyroclastic/volcaniclastic sediments. This kind of geologic setting of forearc basins develop coarse-grained incised valley and canyon fill deposits, distinct associations of lowstand, transgressive and highstand deposits in a deep-water environment, and spatial variations in the timing and nature of sequence boundaries. Furthermore, transgression-related deposits typically contain more volcanogenic clastic fragments, in response to the reduction of active supply of coarse-grained terrigenous sediments to a marine environment and temporal variations in dynamic processes during a relative sea-level cycle. This provides opportunity for characterizing systems tracts within a depositional sequence and further subdivision of stratigraphic successions in terms of transgression-related sedimentary events in various scales.
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