Journal of Tropical Oceanography ›› 2018, Vol. 37 ›› Issue (2): 72-83.doi: 10.11978/2017060CSTR: 32234.14.2017060

Special Issue: 南海专题

• Orginal Article • Previous Articles     Next Articles

Miocene evolution of paleo-water depth and subsidence revealed in Well LF14 from Lufeng Sag, northern South China Sea

Liyuan XUE1(), Xuan DING1(), Renjie PEI2, Xiaoqiao WAN2   

  1. 1. School of Ocean Sciences, China University of Geosciences, Beijing 100083, China
    2. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
  • Received:2017-05-22 Revised:2017-09-06 Online:2018-04-10 Published:2018-04-11
  • Supported by:
    National Natural Science Foundation of China (91328201)

Abstract:

Well LF14, drilled in the Lufeng Sag of the northern South China Sea, discloses marine sediment archives ranging from the mid-to-late period of the early Miocene to the early Pliocene. An abrupt rise in paleo-water depth up to 275 m during the early Miocene is recorded at the lowermost part of the well, followed by several fluctuations thereafter. The early Miocene to early Pliocene deposits are interpreted as formed under middle-to-outer shelf environment, and five complete transgressive-regressive sea-level cycles are identified. The results of backstripping calculations indicate a rapid subsidence in the study area during 17.5-10 Ma. The high sedimentation rate in this period may be caused by rapid tectonic subsidence and high terrigenous input. The subsidence rate was low from 10 to 4.53 Ma, characterized by a low sedimentation rate mainly due to less supply of terrigenous materials and less accommodation space caused by the Dongsha Movement. Finally, several short-lived uplift events were identified in the well based on quantitative reconstruction of paleo-water depth.

Key words: foraminifera, paleo-water depth, tectonic subsidence, Miocene, northern South China Sea