| Project/Area Number |
17403010
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | National Institute of Advanced Industrial Science and Technology |
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Principal Investigator |
SAITO Yoshiki National Institute of Advanced Industrial Science and Technology, Institute of Geology and Geoinformation, Group Leader, 地質情報研究部門, 研究グループ長 (00357071)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥13,600,000 (Direct Cost: ¥13,600,000)
Fiscal Year 2006: ¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 2005: ¥7,100,000 (Direct Cost: ¥7,100,000)
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| Keywords | Mekong River / Southeast Asia / Delta / Holocene / Sea-level change / Paleoenvironment / human activity / mangrove / メコンデルタ |
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| Research Abstract |
Drilling survey at three sites and seismic survey in the Mekong River in Cambodia were conducted to clarify the initiation of the Mekong River Delta and paleo-environments of lowlands in Cambodia during the Holocene. Quaternary strata in the lowlands consists of at least two marine successions: Holocene and late Pleistocene sediments, bounded by an unconformity. Holocene sediments consist of fluvial sediment, tidal-fluvial sediment, and intertidal to subtidal flat sediment. PSG core located near the border of Vietnam contains marine sediments deposited at inter-to sub-tidal flat environment with ages of 8000-8300 cal BP, meaning that the shoreline was located more landward in Cambodia at that time. This marine inundation was occurred by a rapid sea-level rise during 8500-8400 cal BP abruptly, which will be correlated with 8.4-8.5 ka meltwater pulse. Just after the inundation, the Mekong River Delta was initiated at about 8.3 ka and has prograded with aggradational accumulation of 5m-thick peaty sediments distributed widely around Phnom Penh. Tide-dominated environment was changed into more fluvial dominated environment since 6.7 ka to the present with influences of human activities for the last 2 ka.
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