The role of magmatism in the thinning and breakup of the South China Sea continental margin: Special Topic: the South China Sea Ocean Drilling

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Sun, Z., Lin, J., Qiu, N., Jian, Z., Wang, P., Pang, X., Zheng, J., & Zhu, B. The role of magmatism in the thinning and breakup of the South China Sea continental margin: Special Topic: the South China Sea Ocean Drilling. National Science Review, 6(5), (2019): 871-876, doi:10.1093/nsr/nwz116.
Magmatism plays a key role in the process of continental margin breakup and ocean formation. Even in the extremely magma-poor Iberia and Newfoundland margin, studies of field outcrops have shown that syn-rift magmatism had participated in rifting from a very early stage and contributed directly to the rifting process. The final transition from exhumed continental mantle to the ocean formation is also triggered by the accumulation and eruption of magma [1]. Therefore, Atlantic-type passive continental margins are classified into two end-members: magma-poor (non-volcanic) and magma-rich (volcanic). The differences between them lie in whether a large amount of intrusive and extrusive magmatism from the mantle plume/hotspot is involved in the syn-rift and breakup stages. A magma-rich margin [2] should include the following characteristics: (i) a high-velocity lower crust (HVLC) caused by syn-rift mafic magma underplating; (ii) continental crust intruded by abundant sills and dikes; (iii) a large volume of seaward-dipping reflectors (SDRs) caused by flood basalt eruption or tuffs. All other margins are classified as magma-poor margins.
We thank the research team project of Guangdong Natural Science Foundation (2017A030312002), IODP-China and South China Sea Deep Project (91628301) and K.C. Wong Education Foundation (GJTD-2018-13) for providing support for the research. This research was also supported by the China National Science and Technology Major Project (2016ZX05026–003), the joint foundation of the National Natural Science Foundation of China and Guangdong province (U1301233), as well as the National Natural Science Foundation of China (41576070 and 41890813).