The South China Sea is a region of significant importance in terms of the records
of SE Asian tectonics, including Tibetan Plateau uplift, and the onset and evolution of
the East Asian monsoon. The Mekong River has been a dominant sediment source since
at least late Miocene time and has headwaters on the eastern Tibetan Plateau.
Understanding the Pliocene to Recent stratigraphy of the paleo-Mekong Delta and
associated shelf-edge deposits aids in understanding changes in accommodation, sea
level, and sediment supply. This record might then be useful in interpreting the longterm
history of basin evolution in the Nam Con Son Basin.
Nine sequence boundaries and associated sequences are recognized along the late
Miocene to latest Pleistocene shelf in the East Nam Con Son Basin. Age constraints
were assigned to key stratigraphic horizons by correlating sequence boundaries with
published sea level curves. Accommodation in the study area is controlled by shelf -edge
compaction, rift-related thermal subsidence, non-rift-related anomalous subsidence,Two primary sources supplied sediment to the southwestern South China Sea
during Pliocene to Recent time and likely include the paleo-Mekong Delta and a fluviodeltaic
system originating from the Sunda Shelf, such as the Molengraaff River. Changes
in thickness, area, and location of Pliocene to Recent shelf-edge delta deposits reflect
changes in accommodation and sediment supply over time, as well as progradation of
the shelf edge during Pliocene to Recent time and avulsion of the shelf edge delta.
Anomalous subsidence of LGM shelf edge deposits is estimated at approximately
40-50 m deeper than expected. The current depth of the LGM deltaic wedge may
indicate renewed rapid tectonic subsidence during the last 18,000 yrs, possible
compaction effects or a combination of these.
eustatic change, and shelf edge faulting.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-1128 |
| Date | 15 May 2009 |
| Creators | Wright, Christine M. |
| Contributors | Dorobek, Steven L. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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