华南东部陆缘新生代隆升历史及其动力学机制  

Cenozoic uplift history and its dynamic mechanism along the eastern continental margin of South China

作　　者：王新毓 索艳慧[1,2] 李三忠 曹现志[1,2] 李玺瑶 周洁[1,2] 王鹏程 金宠 WANG XinYu;SUO YanHui;LI SanZhong;CAO XianZhi;LI XiYao;ZHOU Jie;WANG PengCheng;JIN Chong(MOE Key Lab of Submarine Geosciences and Prospecting Technique,College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266237,China;Zhejiang Institute of Geology and Mineral Resource,Hangzhou 310012,China)

机构地区：[1]海底科学与探测技术教育部重点实验室,中国海洋大学海洋地球科学学院,青岛266100 [2]青岛海洋科学与技术国家实验室海洋地质功能实验室,青岛266237 [3]浙江地质矿产研究所,杭州310012

出　　处：《岩石学报》2020年第6期1803-1820,共18页Acta Petrologica Sinica

基　　金：国家重点研发计划(2017YFC0601401);国家自然科学基金项目(91958214);山东省泰山学者特聘教授项目、鳌山卓越科学家计划(2015ASTP-0S10)联合资助。

摘　　要：华南陆缘在新生代期间经历了千米量级的上覆盖层剥蚀和山脉隆升;同时,其东侧的东海陆架盆地经历多次构造应力场的反转并发育多期反转构造。东海陆架盆地内的构造反转与华南陆缘隆升的发生时间和触发机制是否一致有待研究。为此,本文对浙江地区的岩石样品进行磷灰石裂变径迹测试和热演化史反演分析其隆升历史,并通过地震剖面分析东海陆架盆地的反转时间及其反转所导致的地层剥蚀量;最后,将二者进行对比分析并研究其动力学机制。结果发现,华南东部陆缘地区至少存在晚始新世(34.5~33.5Ma)、中中新世(16~11.5Ma)、上新世以来(5~0Ma)三期明显的快速隆升事件,三期隆升导致的地层剥蚀量分别为227m、593m和865m;东海陆架盆地经历了古新世末-始新世初(~56Ma)、始新世末-渐新世初(~32Ma)和晚中新世(~10Ma)三期构造反转,三期反转导致的局部地层最大剥蚀量分别可达1200m、1300m和2000m。在时间上,东海陆架盆地的始新世末-渐新世初(~32Ma)和晚中新世(~10Ma)的构造反转分别滞后于浙江的晚始新世(34.5~33.5Ma)和中中新世(16~11.5Ma)的隆升时间,说明这两期挤压-剥蚀事件分别具有自西向东的迁移性,即印度-欧亚板块碰撞的远程效应可能是导致该迁移特征的原因;在强度上,东海陆架盆地的反转剥蚀量大于浙江境内的地层隆升量、挤压强度东强西弱,中新世晚期菲律宾海板块向西俯冲导致冲绳海槽弧后伸展产生向西的挤压力、这种挤压应力向陆内传递且强度变弱可能是导致该特征的原因。The eastern continental margin of South China experienced a denudation and uplift with a thickness up to more than one kilometer during the Cenozoic.Simultaneously,its adjacent East China Sea Shelf Basin(ECSSB)developed several phases of tectonic inversion due to the transition of tectonic stress regime from tension to compression.Whether the uplift in the Southeast China continental margin and the tectonic inversion in the ECSSB are the similar tectonic responses to the same geological events or under a same geodynamic mechanism remains debated.Using apatite fission track data and seismic profiles,this paper modeled the thermal uplift evolutionary history in Zhejiang Province and the inversion phases in the ECSSB.The results show that at least three rapid uplift events occurred in Zhejiang Province at the Late Eocene(34.5~33.5Ma),the Middle Miocene(16~11.5Ma)and the Pliocene(5~0Ma),respectively,which caused sedimentary erosions with thicknesses up to 227m,593m and 865m,respectively.Meanwhile,the adjacent ECSSB developed three phases of tectonic inversions at the Latest Paleocene-the Earliest Eocene(~56Ma),the Latest Eocene-the Earliest Oligocene(~32Ma),and the Late Miocene(~10Ma),respectively,which caused maximum thicknesses of local erosions up to 1200m,1300m and 2000m,respectively.Temporally,both the Latest Eocene-the Earliest Oligocene(~32Ma)and the Late Miocene(~10Ma)inversions in the ECSSB are later than the 34.5~33.5Ma and 16~11.5Ma uplifts in Zhejiang Province,indicating that the compression-erosion event has an eastward migration probably due to the far-field effects of the Indian-Eurasian collision.Spatially,the amount of sedimentary denudation of the ECSSB is greater than that of Zhejiang Province,which may be caused by the westward decreasing compression generated by the back-arc extension of the Okinawa Trough that was induced by the Late Miocene westward subduction of the Philippine Sea Plate.

关 键 词：华南东部陆缘 东海陆架盆地 新生代 磷灰石裂变径迹 反转构造 

分 类 号：P542[天文地球—构造地质学]