Cenozoic stratigraphy of Taiwan:Window into rifting,stratigraphy and paleoceanography of South China Sea
Cenozoic stratigraphy of Taiwan:Window into rifting,stratigraphy and paleoceanography of South China Sea作者机构:Key Laboratory of Marginal Sea Geology Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China State Key Laboratory of Marine Geology School of Ocean and Earth Sciences Tongji University Shanghai 200092 China
出 版 物:《Chinese Science Bulletin》 (中国科学通报)
年 卷 期:2012年第57卷第24期
页 面:3130-3149页
核心收录:
学科分类:070704[理学-海洋地质] 0709[理学-地质学] 07[理学] 0707[理学-海洋科学]
基 金:supported by the National Natural Science Foundation of China (91128211 and 41176041) the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-EW-101)
主 题:新生代地层 中国南海 台湾海峡 古海洋学 地层学 裂谷 底栖有孔虫 中中新世
摘 要:Shallow marine sequences of the northern South China Sea (SCS) are uplifted and exposed by plate convergence in the Taiwan mountain belt. These deposits provide detailed geological information about the rifting event, stratigraphy, sedimentology, paleoclimate and paleoceanography of the shallow SCS to compare with what are recorded in the ODP 1148 deep-sea core. Seismic surveys and marine micropalentological studies show that Eocene sequences in the offshore Taiwan Strait and onland Taiwan mountain belt are all deposited in rifting basins and are covered unconformably by the Late Oligocene-Neogene post-rifting strata. Between syn-rifting and post-rifting sequences, there is a regional break-up unconformity throughout the island. Early Oligocene and Late Eocene strata are missing along the break-up unconformity equivalent to the T7 unconformity in the Pearl River Mouth Basin off south China. This may suggest that the SCS oceanic crust could have initiated between 33 and 39 Ma. Neither obvious stratigraphic gap nor slumping features are found in the Oligocene-Miocene transition interval of Taiwan. This observation highly contrasts with what has been documented from the ODP 1148 deep-sea core. This suggests that the stratigraphic gap and slumping features could only be recorded in the SCS deep sea region, but not in the shallow shelf near Taiwan. Compared to the Middle Miocene paleoceanographic re-organization events in the SCS deep sea, the geological history of the Taiwan shallow sequence shows changes of in sedimentation and faunal composition. Due to the Antarctic glacial expansion at^14 Ma, Middle to late Miocene strata of the Western Foothills show progressive regression sedimentations associated with a decrease of benthic foraminif-eral abundance and a sharp faunal turnover event. Many Early-Middle Miocene endemic benthic foraminifers were extinct in 14-13 Ma and new benthic foraminifers of the Kuroshio Current fauna appeared from 10.2 Ma, comparable with new oc