Carbonates

Carbonate Studies in SE Asia

Modern tropical carbonate production is most prolific in the clear shallow waters of SE Asia and almost half the world’s coral reefs and the greatest species diversity of corals occurs in this area. Carbonate production was also common in the shallow marine seas of SE Asia during the Cenozoic and outcrop studies reveal that the ancient carbonate depositional environments are analogous to the present day.

This programme focuses on the distribution and character of carbonate rocks in SE Asia, with the aim of producing a comprehensive regional review of the history and setting of carbonate sedimentation, carbonate depositional environments, and the development, demise and diagenesis of carbonate platforms. Tropical carbonates of Cenozoic age are of considerable economic importance in SE Asia as hydrocarbon reservoirs, raw materials for the construction and pharmaceutical industries, for their role in the hydrology cycle, and as unique natural habitats.

Completed projects:

These modern and Cenozoic carbonates are extremely diverse, but also quite different from extensively studied modern subtropical carbonates, such as the Bahamas, Red Sea and Arabian Gulf.

Coated grains are lacking and the carbonates are almost entirely bioclastic in nature. Depositional facies, platform structure, nature and rates of production consequently differ considerably.
A diverse array of carbonate depositional systems and environments occur, characterised by a range of biotic community structures.
SE Asia is an extremely active area where tectonics and volcanic activity both strongly control the development of carbonate facies.
There is a long and continuous geological record of tropical carbonate deposition from the Eocene to the present day.
The interchange of Pacific and Indian oceanic waters occurs in SE Asia, and in this fully marine, unenclosed setting associations with evaporite deposits are extremely rare.

Cenozoic Carbonate Depositional Systems Studied

Cenozoic carbonates in SE Asia were deposited in a wide variety of depositional settings. Most of the systems can be studied at outcrop in Borneo, Sulawesi and Java and equivalent modern depositional environments occur in the shallow waters of the Makassar Straits which separate these islands. Depositional systems studied include:

Large scale isolated syntectonic platforms
Land attached carbonate or mixed carbonate clastic shelves
Isolated and ephemeral carbonates, such as fault block carbonates, isolated knoll reefs, patch reefs or shoals on clastic shelves, delta front patch reefs or carbonates associated with volcanics.

Recent Papers –

Max Webb et al., 2020. Isotopic mapping reveals the location of crustal fragments along a long-lived convergent plate boundary. Lithos.

https://doi.org/10.1016/j.lithos.2020.105687

Max Webb et al., 2020. The history of Cenozoic magmatism and collision in NW New Guinea – New insights into the tectonic evolution of the northernmost margin of the Australian Plate. Gondwana Research.

https://doi.org/10.1016/j.gr.2019.12.010

Amy Gough et al., 2020. Mid-Cenozoic fluvio-deltaic to marine environments of the Salin Sub-basin, Central Myanmar. Journal of Asian Earth Sciences.

https://doi.org/10.1016/j.jseaes.2019.104143

Recent News –

Amy Gough and Max Webb attended the Restech 2.0 Virtual Reservoir Conference. Amy Gough presented new SEARG research on the pitfalls of light mineral studies for sedimentary provenance in tropical climates.

Amy Gough was awarded an honorary research fellowship of the British Geological Survey and continues to foster collaborative relationships between SEARG and the BGS.