| 琼东北晚新生代断裂活动及其对东寨港沉降的控制作用 |
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| 关键词:Hainan Island Leiqiong depression neotectonic movement active fault Puqian–Qinglan fault |
| 基金项目:中国地质调查局地质调查项目“泛珠三角地区活动构造与区域地壳稳定性调查”(编号: DD20160269) |
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| Late Cenozoic Fault Activity in Northeastern Hainan Island and Its Controlling Effect on Tectonic Subsidence in Dongzhai Port |
| The Qiongzhou great earthquake of magnitude 7.5 in 1605 caused extensive land subsidence into the sea. Previous studies have paid much attention to the land subsidence lagoon plain and Jinshan eroded platform, which are controlled by the regional NW-trending faults. The se-dimentation thickness map based on data of 86 drill holes at different stages since the Neogene was compiled, which shows that the sedimentation center is transferred from the west bank to the east bank and the average deposition rates also have significant change. The average deposition rates of the Mesozoic–Pliocene, Early Pleistocene, Late Pleistocene and Holocene were 12 mm/ka, 10 mm/ka, 67 mm/ka and 1 922 mm/ka respectively, which suggests that the deposition rate was slow before the Middle Pleistocene, began to increase suddenly in the Late Pleistocene, and probably reached the maximum since the Holocene. Some conclusions have been reached: (1) The Dongzhai port graben was mainly controlled by NW-trending Quaternary normal Puqian–Qinglan fault that also controlled the development of Dongzhai port graben, its subsidence into the sea and its continuous sink. (2) The subsidence of Dongzhai port depression has been accelerated since the Late Pleistocene. (3) Jinshan eroded platform has been long in a stable or slightly uplift state, and is likely to belong to the tectonic block outsidethe Lei–Qiong Depression. The problem whether the Leiqiong depression includes Jinshan eroded platform deserves further study.mechanism, but there is still a lack of in-depth study of the fault activities as well as the process and the mechanism of tectonic subsidence since the Late Cenozoic. Based on field investigation, drill hole data and EH4 inversion analysis, the authors divided the Dongzhai port area into three tectonic geomorphologic units, namely, Yanfeng volcanic platform, Dongzhai |
| DING Ying-ying,ZHAO Xi-tao,HU Dao-gong,ZHANG Xu-jiao,WANG Chao-qun,HU Zheng-wang,XIA Meng-meng,WU Huan-huan,YOU Bao-jie,CHANG Peng-yuan.2018.Late Cenozoic Fault Activity in Northeastern Hainan Island and Its Controlling Effect on Tectonic Subsidence in Dongzhai Port[J].Acta Geoscientica Sinica,39(2):155-166. |
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