Details of Award
NERC Reference : NE/D001358/1
Stratigraphic evolution of the Red River Delta and Fan Complex, South China Sea.
Grant Award
- Principal Investigator:
- Professor PD Clift, University of Aberdeen, Geology and Petroleum Geology
- Co-Investigator:
- Dr AM Schwab, University of Aberdeen, Geology and Petroleum Geology
- Grant held at:
- University of Aberdeen, Geology and Petroleum Geology
- Science Area:
- Marine
- Earth
- Overall Classification:
- Marine
- ENRIs:
- Global Change
- Science Topics:
- Earth Resources
- Sediment/Sedimentary Processes
- Palaeoenvironments
- Climate & Climate Change
- Abstract:
- Earth's climate is a dynamic system that has changed radically in the geological past as a result of changes in extraterrestrial influences, such as the intensity of solar rays reaching the atmosphere. However, changes in the configuration of the solid Earth, such as shape, altitude and location of continents, as well as opening and closure of ocean basins is considered to be a key control on climate over time spans of more than one million years. The Earth has cooled significantly since 50 million years ago, while the Asian monsoon has strengthened since at least 8 million years ago and maybe considerably before that time. Both of these climatic changes have been tied to the uplift of the Tibetan Plateau, the largest mountain range on Earth for 500 million years. However proving a link between mountain building and climate change, and recording in detail how climate, erosion and tectonic activity interact has yet to be achieved. IODP drilling operations on the Red River delta and deep water fan system, proposed by Clift and colleagues (proposal #618), are designed to understand how the flux of material from that river has changed in the last 50-60 million years. Because the Red River erodes the eastern flank of Tibet and lies in a region of strong summer monsoon activity the erosion of the gorges that cut the plateau margin should be strongly linked to the surface uplift and to climate changes. Moreover, uplift is thought to have caused the Red River to have lost drainage through capture events to the adjacent river systems, such as the Salween, Mekong and Yangtze, although the timing of these capture events remains obscure. An important test of the hypothesis that uplift drives faster erosion through elevating the mountain sources and strengthening the summer rains lies in dating and quantifying the mass (sediment) flux from the mountains into the Red River delta. This can be achieved through imaging the sediment volumes in the offshore region using existing marine seismic data collected by oil companies and now released for scientific research to Clift and Schwab. The small amount of sediment preserved onshore can also be accounted for (~2% of the total). Tying together data from both the Chinese and the Vietnamese sides of the offshore basin must be done in order to place the drilling sites in context and to verify that they are located in the optimal positions. A sediment budget for the Red River can be generated by calculating the volume of sediment packages from the seismic data, using standard decompaction methods on depth converted time surfaces. Reflections that define each depositional package can be dated where they intersect drill sites. Detailed ages can only be provided by IODP drilling, yet in the short term existing industrial wells will provide a low-resolution, first order age framework based on microfossil evidence that will answer the question of how erosion varied through time. Although these data by themselves cannot uniquely explain how climate, tectonics and erosion interact, they do provide important constraints on what is possible. Because the age of faulting and magmatic events in Tibet are known at least in outline, it will be possible to compare the erosional flux with these process. Similarly, although a detailed climate history is only known since ~25 million years ago in the South China Sea it will be possible to use these records, largely produced after ODP Leg 184, to test whether periods of wetter and drier conditions were a primary control on the erosional flux carried by the Red River. Once the stratigraphic framework has been generated then higher resolution dating from IODP can be readily incorporated, thus allowing a more detailed correlation of erosional events with tectonic and climatic episodes.
- NERC Reference:
- NE/D001358/1
- Grant Stage:
- Completed
- Scheme:
- Directed Pre FEC
- Grant Status:
- Closed
- Programme:
- IODP
This grant award has a total value of £19,644
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - T&S | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £3,277 | £9,378 | £5,481 | £1,507 |
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