洞庭湖盆地中强震不对称分布与地球动力学机制

doi:10.12196/j.issn.1000-3274.2022.04.007

摘要/Abstract

摘要： 洞庭湖盆地为扬子块体内部地震活动最活跃的区域, 湖南省有历史记载以来最大地震1631年常德6¾级地震震中位于盆地的西缘, 中强震也多分布于该区域, 然而现今沉积中心盆地东部却无中强震记录。前人对盆地及发震构造研究均认为该区强震受盆地凹陷正断裂控制, 且主要由拉张应力所致, 但这一认识很难解释中强震不对称分布现象。基于近期开展的地质调查和第四纪沉积研究的最新成果, 并结合低温热年代学、地球物理探测及应力场研究的最新认识, 以及盆地及周边地貌研究, 综合分析得出盆地中强地震分布不对称性原因: 新生代以来, 由于太平洋板块的后撤, 盆地区域深部地幔隆升及热作用衰减, 盆地拉张作用也相应减弱, 而新近纪以来盆地西侧受青藏高原向东运动的影响, 四川盆地沉积盖层向东持续推挤, 扬子地台西部结晶基底之上的沉积盖层受挤压作用影响, 盆地西缘明显抬升, 沉积中心向东迁移, 挤压作用也可能是该区域地震发生的主要动力来源。

关键词: 洞庭湖盆地, 构造地貌, 1631年常德6¾级地震, 凹陷盆地, 青藏高原

Abstract: Dongting Basin is the most active seismic area in Hunan Province, China. According to historical records, the Changde M6¾ earthquake occurred in 1631 was the largest earthquake in the province, and most of the moderate and strong earthquakes were distributed in the western margin of the basin. However, there are no strong earthquake records in the present sedimentary center. Previous studies on the basin tectonic and seismogenic believe that the strong earthquakes in this area are controlled by the normal faults of the basin depression, but it is difficult to explain the asymmetry of strong earthquake distribution. Based on the latest results of geological survey and Quaternary sedimentary research, combined with the consensus of tectonic geomorphology, low-temperature thermochronology, geophysical exploration and stress field, the causes of asymmetric distribution of moderate strong earthquakes in the basin is analyzed. In addition to deep mantle uplift and basin extension and depression, the main reason is the eastward movement of Qinghai-Tibet Plateau and Sichuan Basin under the eastward pushing for gravitational potentional energy, the sedimentary cap rocks in the southwestern margin of the basin are obviously compressed and uplifted, which is also the main dynamic source of earthquake occurrence in this region.

Key words: Dongting Basin, Tectonic landform, the 1631 Changde M6¾ earthquake, Depression basin, Qinghai-Tibet Plateau

中图分类号:

P546

赵峥, 杨攀新, 熊仁伟, 胡朝忠. 洞庭湖盆地中强震不对称分布与地球动力学机制[J]. 地震, 2022, 42(4): 89-99.

ZHAO Zheng, YANG Pan-xin, XIONG Ren-wei, HU Chao-zhong. Asymmetric Distribution of Moderate-Strong Earthquakes and Geodynamic Mechanism in Dongting Basin[J]. EARTHQUAKE, 2022, 42(4): 89-99.

参考文献

[1] 董瑞树, 周庆, 陈晓利, 等. 1631年湖南省常德地震的再考证[J]. 地震地质, 2009, 31(1): 162-173.
DONG Rui-shu, ZHOU Qin, CHEN Xiao-li, et al. The re-verification of Changde, Hunan, earthquake in 1631[J]. Seismology and Geology, 2009, 31(1): 162-173 (in Chinese).
[2] 徐杰, 邓起东, 张玉岫, 等. 江汉-洞庭盆地构造特征和地震活动的初步分析[J]. 地震地质, 1991, 13(4): 332-342.
XU Jie, DENG Qi-dong, ZHANG Yu-xiu, et al. Structural features and seismicity in Jianghan-Dongting Lake Basin[J]. Seismology and Geology, 1991, 13(4): 332-342 (in Chinese).
[3] 赵凌强, 詹艳, 周本刚, 等. 1631年常德历史地震区深部结构的大地电磁探测研究[J]. 地震地质, 2018, 40(1): 155-170.
ZHAO Ling-qiang, ZHAN Yan, ZHOU Ben-gang, et al. Deep structure beneath the 1631 Changde, Hunan M6 earthquake area derived from magnetotelluric sounding[J]. Seismology and Geology, 2018, 40(1): 155-170 (in Chinese).
[4] 沈得秀, 周本刚, 杨晓平, 等. 湖南太阳山隆起区断层活动性研究[J]. 中国地震, 2008, 24(1): 38-47.
SHEN De-xiu, ZHOU Ben-gang, YANG Xiao-ping, et al. Activity characteristics of the Taiyangshan uplift area in Hunan, China[J]. Earthquake Research in China, 2008, 24(1): 38-47 (in Chinese).
[5] 柏道远, 李长安, 周柯军, 等. 第四纪洞庭盆地赤山隆起与安乡凹陷升降运动的沉积记录[J]. 沉积学报, 2010, 28(4): 645-658.
BAI Dao-yuan, LI Chang-an, ZHOU Ke-jun, et al. Geological characteristics and tectonic-sedimentary coupling relation of the Chishan uplift and Anxiang sag of quaternary Dongting Basin[J]. Acta Sedimentologica Sinica, 2010, 28(4): 645-658 (in Chinese).
[6] 柏道远, 李长安, 王先辉, 等. 第四纪洞庭盆地构造性质及动力机制探讨[J]. 大地构造与成矿学, 2010, 34(3): 317-330.
BAI Dao-yuan, LI Chang-an, WANG Xian-hui, et al. Quaternary tectonic characteristics and dynamic mechanisms of the Dongting Basin[J]. Geotectonica et Metallogenia, 2010, 34(3): 317-330 (in Chinese).
[7] 柏道远, 李送文, 周柯军, 等. 1∶25万常德市幅构造-沉积地貌类型划分及其对江汉—洞庭盆地第四纪地质与环境研究的启示[J]. 中国地质, 2010, 37(2): 280-297.
BAI Dao-yuan, LI Song-wen, ZHOU Ke-jun, et al. Tectonic-sedimentary landform classification of 1∶250000 Changde Sheet and its implication for researches on Quaternary geology and environment of Jianghan-Dongting Basin[J]. Geology in China, 2010, 37(2): 280-297 (in Chinese).
[8] 柏道远, 刘波, 李长安, 等. 第四纪洞庭盆地临澧凹陷构造-沉积特征与环境演化[J]. 山地学报, 2010, 28(6): 641-652.
BAI Dao-yuan, LIU Bo, LI Chang-an, et al. Quaternary tectonic-sedimentary characteristics and environmental evolution of Linli sag, Dongting Basin[J]. Journal of Mountain Science, 2010, 28(6): 641-652 (in Chinese).
[9] Shen C B, Mei L F, Min K. et al. Multi-chronometric dating of the Huarong granitoids from the middle Yangtze Craton: Implications for the tectonic evolution of eastern China[J]. Journal of Asian Earth Sciences, 2012, 52: 73-87.
[10] 王韶华, 罗开平, 刘光祥. 江汉盆地周缘中、新生代构造隆升裂变径迹记录[J]. 石油与天然气地质, 2009, 30(3): 255-259.
WANG Shao-hua, LUO Kai-ping, LIU Guang-xiang. Fission track records of tectonic uplift during the Cenozoic and Mesozoic in the periphery of the Jianghan Basin[J]. Oil & Gas Geology, 2009, 30(3): 255-259 (in Chinese)
[11] 吴路路. 江汉盆地的开始、演化与夭折: 基底构造与地幔动力的共同制约[D]. 武汉: 中国地质大学, 2019.
WU Lu-lu. The initiation, volution and abandonment of the Jianghan Basin: Combined influence of basement structures and mantle dynamics[D]. Wuhan: China University of Geosciences, 2019 (in Chinese).
[12] Niu Y L. Generation and evolution of basaltic magmas: Some basic concepts and a new view on the origin of Mesozoic-Cenozoic basaltic volcanism in eastern China[J]. Geological Journal of China Universities, 2005, 11(1): 9-46.
[13] Dong Y P, Zhang G W, Neubauer F, et al. Tectonic evolution of the Qinling orogen, China: Review and synthesis[J]. Journal of Asian Earth Sciences, 2011, 41(3): 213-237.
[14] Shen C B, Donelick R A, O'Sullivan P B, et al. Provenance and hinterland exhumation from LA-ICP-MS zircon U-Pb and fission-track double dating of Cretaceous sediments in the Jianghan Basin, Yangtze block, central China[J]. Sedimentary Geology, 2012, 281: 194-207.
[15] Liu S F, Steel R, Zhang G W. Mesozoic sedimentary basin development and tectonic implication, northern Yangtze Block, eastern China: record of continent-continent collision[J]. Journal of Asian Earth Sciences, 2005, 25(1): 9-27.
[16] 陈渡平, 李长安, 柏道远, 等. 洞庭盆地第四纪地层格架初拟[J]. 地质科技情报, 2014, 33(1): 67-73.
CHEN Du-ping, LI Chang-an, BAI Dao-yuan, et al. Preliminary discussion on the quaternary stratigraphic framework of Dongting Basin[J]. Geological Science and Technology Information, 2014, 33(1): 67-73 (in Chinese).
[17] 李双建, 李建明, 周雁, 等. 四川盆地东南缘中新生代构造隆升的裂变径迹证据[J]. 岩石矿物学杂志, 2011, 30(2): 225-233.
LI Shuang-jian, LI Jian-ming, ZHOU Yan, et al. Fission track evidence for Mesozoic-Cenozoic uplifting in the southeastern margin of Sichuan Basin[J]. Acta Petrologica et Mineralogical, 2011, 30(2): 225-233 (in Chinese).
[18] Shen C B, Mei L F, Xu S H. Fission track dating of Mesozoic sandstones and its tectonic significance in the eastern Sichuan Basin, China[J]. Radiation Measurements, 2009, 44(9): 945-949.
[19] 余武, 沈传波, 杨超群. 秭归盆地中新生代构造-热演化的裂变径迹约束[J]. 地学前缘, 2017, 24(3): 116-126.
YU Wu, SHEN Chuan-bo, YANG Chao-qun. Constraints of fission track dating on the Mesozoic-Cenozoic tectonic-thermal evolution of the Zigui Basin[J]. Earth Science Frontiers, 2017, 24(3): 116-126 (in Chinese).
[20] 平亚敏, 杨桂芳, 张绪教, 等. 张家界砂岩地貌形成时代: 来自阶地与溶洞对比的证据[J]. 地质论评, 2011, 57(1): 118-124.
PIN Ya-min, YANG Gui-fang, ZHANG Xu-jiao, et al. Timing of Zhangjiajie sandstone landforms: Evidence from fluvial terraces and karst caves[J]. Geological Review, 2011, 57(1): 118-124 (in Chinese).
[21] 谢明. 长江三峡地区第四纪以来新构造上升速度和形式[J]. 第四纪研究, 1990, 10(4): 308-315.
XIE Ming. Neotectonic uplift velocity and type along the Changjiang river during quaternary[J]. Quaternary Sciences, 1990, 10(4): 308-315 (in Chinese).
[22] 杨攀新, 高战武, 张俊. 江汉盆地构造模式和演化及其与中强地震关系研究[J]. 地震, 2009, 29(4): 123-130.
YANG Pan-xin, GAO Zhan-wu, ZHANG Jun. Structure model and evolution of the Jianghan basin and relation with moderate to strong earthquakes[J]. Earthquake, 2009, 29(4): 123-130 (in Chinese).
[23] 田优平, 唐红亮, 康承旭, 等.综合震源机制解法反演湖南地区构造应力场的初步结果[J]. 地球物理学报, 2020, 63(11): 4080-4096.
TIAN You-ping, TANG Hong-liang, KANG Cheng-xu, et al. Preliminary results of inversion of tectonic stress field in Hunan region by the composite focal mechanism method[J]. Chinese Journal of Geophysics, 2020, 63(11): 4080-4096 (in Chinese).