Dr. Zhen Sun [CAS Key Laboratory of Ocean and Marginal Sea Geology, China]

Title: Breakup Mechanism of the South China Sea--The Scientific Objectives of IODP Expedition 367-368

南海的破裂机制—IODP367-368航次的科学目标?

Time: 9:30 - 10:15 AM, Thursday, July 7, 2016

Place: Auditorium Room 410, HPSTAR (Shanghai)

Host: Dr. Jinfu Shu & Dr. Bin Chen

Abstract:

Based on geophysical studies and scientific ocean drilling along the North Atlantic rifted continental margins, two end-members of the rift-to-drift process were established: Volcanic rifted margins with anomalous magmatism versus magma-poor (non-volcanic) margins with extremely limited magmatism associated with continental breakup. Volcanic rifted margins are hypothesized to be associated with deep mantle plumes, while non-volcanic margins are linked to deep faults that allow water penetrating into the lithospheric mantle. The latter causes a profound weakening of the continental lithosphere due to mantle serpentinization in support of final breakup. Interestingly, the northern continental margin of the South China Sea (SCS) between longitude 114.5º and 116.5º host features that might be similar to both of the two end-members defined in the North Atlantic. However, there are also indications of lower crustal flow toward the SCS. It will require deep drilling and sampling of characteristic basement units within the COT to distinguish between a breakup model involving lower crustal flow towards the COT as opposed to serpentinization of the subcontinental lithospheric mantle. Four months of drilling by IODP to address this question is scheduled for 2017. The IODP drilling has the potential to support a third breakup mechanism theorized by modelling in addition to the two types of rifted margin already constrained by drilling, i.e., volcanic, plume supported versus Iberia-type magma starved.

Biography of the Speaker:

Dr. Zhen Sun is a marinegeologist. She and her team mainly work on structures, geophysics, dynamics and sedimentation process of the continental margins. Recently, they started to work on subduction zone.

In order to reveal the rifting-breakup history and the breakup mechanism, Dr. Sun led an IODP drilling proposal with her colleagues in IODP-China. Now it has been scheduled as two consecutive legs in 2017, from Feburary to June.

Dr. Sun graduated from Nanjing University in 1997 and then went to China University of Geosciences for her Ph.D degree.