2001 Fiscal Year Final Research Report Summary
High-Resolution Study of Subsurface Geology using Core-Log Data Integration
Project/Area Number |
12640439
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Geology
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Research Institution | The University of Tokyo |
Principal Investigator |
TAIRA Asahiko The Univ. of Tokyo, Ocean Research Institute, Professor, 海洋研究所, 教授 (50112272)
|
Co-Investigator(Kenkyū-buntansha) |
KINOSHITA Masataka Japan Marine Science and Technology Center, Deep Sea Research Dept., Associate Scientist, 深海研究部, 研究副主幹 (50225009)
ASHI Juichiro The Univ. of Tokyo, Ocean Research Institute, Associate Prof., 海洋研究所, 助教授 (40251409)
TOKUYAMA Hidekazu The Univ. of Tokyo, Ocean Research Institute, Professor, 海洋研究所, 教授 (10107451)
SAITO Saneatsu Japan Marine Science and Technology Center, Deep Sea Research Dept., Associate Scientist, 深海研究部, 研究副主幹 (40292859)
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Project Period (FY) |
2000 – 2001
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Keywords | Downhole Logging / Physical Property / Paleoenvironment / Sedimentology / Structural Geology / Nankai Trough / Ocean Drilling Program |
Research Abstract |
In 2001, a software package for downhole logging data analysis called Geoframe was introduced to Ocean Research Institute, University of Tokyo. Using this software the logging data obtained through Ocean Drilling Program Leg 186 and 196 were processed. The resistivity formation scanner data from the forearc basin off Sanriku showed clear image of mudstone and dolomite intercalation. Leg 196 data at the decollement horizon of the Nankai subduction zone indicate complex network of porosity structure of the fault zone. Logging data obtained from 200m drilling at Choshi, Chiba Prefecture showed cyclic singles of porosity, natural gamma-ray and resistivity. Such cyclic variability of logging data was correlated with oxygen isotope variability for last 400K yr. ago to 800 yr. ago. Examination of both lithological data and logging data, it was possible to show that the Kuroshio-Oyashio fluctuation according to glacial and interglacial cycles was a cause for the physical property cyccles. This study demonstrated that combined analysis of samples and logging data produces a powerful tool for sedimentology and structural geology.
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