Evolution of the continental margin of south to central Vietnam and its relationship to opening of the South China Sea (East Vietnam Sea)

This study used apatite thermochronometry to examine the uplift history of South-Central Vietnam to better understand how the elevated landscape formed, and to see if it is connected to the eruption of the widespread basalt flows that cover many of the high elevation plateaus. Results showed a match in the timing between a period of rapid cooling between 37-30 million years ago that affected the entire region and a period of fast rifting and extension that ended with continental breakup. To fully understand the cause of cooling thermal models tested different scenarios. Thermal relaxation after magmatism was discounted at it took place well before the period of rapid cooling. Models support fast cooling attributed to accelerated erosion during early stages of rifting. Magmatic underplating associated with rifting might also have produced additional heating but no evidence was found to support regional uplift associated with the basalt magmatism.