The Crustal Stress Field around the Ordos Block
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摘要: 收集了鄂尔多斯周缘的297个震源机制解数据,应用震源机制解反演应力场的网格搜索法分区反演该地块周缘地区平均应力场。应力场反演结果显示:该地块周缘地区地壳应力场总体表现为NE-SW向的主压应力,NW-SE向的主张应力。北缘的河套活动断陷带处于ENE-WSW向的水平挤压和NNW-SSE向的水平拉张共同作用的应力状态。南缘的渭河断陷带处于近NS向的水平拉张应力状态。东缘的山西断陷盆地带处于NNW-SSE向的水平拉张应力状态。在地块西面,主压应力轴方向由南段的ENE向逐渐向中段逆时针转为近NE向,继而往北转为NNE向。应力场反演结果和鄂尔多斯地块NS两侧呈EW向展布的断陷带表现为左旋剪切拉张带以及EW两侧呈NNE向展布的断陷带则表现为右旋剪切拉张带的性质一致。本研究结果与前人的研究结果一致性较好,说明了结果的可靠性。Abstract: Based on 297 focal mechanism solutions around the Ordos block, the stress field around the Ordos block was inversed. The inversion result indicates that the principal compression stress direction around the Ordos block is NE-SW and the principal tension stress direction is NW-SE. Hetao active fault subsidence zone, on north edge of the block, are under the joint action of the ENE-WSW horizontal compression and the NNW-SSE horizontal tension stress field. Weihe fault subsidence zone is under the tension of the nearly NS horizontal stress field. Shanxi faulted basin zone is under the tension of the NNW-SSE horizontal stress field. In the west of the Ordos block, the strikes of the principal compression stress axes from south to north, and turn gradually from ENE to NNE direction. Both the Weihe faulted basin zone and Hetao faulted basin zone are nearly EW-trending left-lateral shear zones with extension components, while both the Shanxi faulted basin zone and Yinchuan-Jilantai faulted basin zone are NNE-trending right-lateral shear zones with extension components, that accord with our study results. Our inversion results are similar with previous studies, which indicate the reliability of our study result.
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Key words:
- Ordos block /
- stress field /
- focal mechanism solutions
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[1] 陆远忠,李胜乐,邓志辉,等. 基于GIS的地震分析预报系统[M].成都:成都地图出版社,2002:179-186. [2] 邓起东,程绍平,闵伟,等. 鄂尔多斯块体新生代构造活动和动力学的讨论[J].地质力学学报,1999,5(3):13-21. [3] 国家地震局鄂尔多斯周缘活动断裂系课题组.鄂尔多斯周缘活动断裂系[M].北京:地震出版社,1988. [4] 李孟銮,赵知军.宁夏地区的震源机制与应力场[J].西北地震学报,1981,3(4):49-55. [5] 刘巍,赵新平,安卫平,等.山西地区的地壳应力场[J].山西地震,1993,(3):3-11,34. [6] 谢富仁,舒塞兵,窦素芹,等.海原、六盘山断裂带至银川断陷第四纪构造应力场分析[J].地震地质,2000,22(2): 139-146. [7] 孙贵成,郭祥云,马利军. 山西带中北部地区中小地震震源机制解特征[J]. 华北地震科学,2015,33(1):52-56. [8] 刘芳,王晓山,杨雅琼. 内蒙古中西部地区小震震源机制解分析[J]. 大地测量与地球动力学,2010,30(sp1):7-11. [9] 薛宏运,鄢家全.鄂尔多斯地块周围的现代地壳应力场[J].地球物理学报,1984,27(2):144-152. [10] 范俊喜,马瑾,刁桂苓.由小震震源机制解得到的鄂尔多斯周边构造应力场. 地震地质,2003.25(1):88-99. [11] 万永革.根据震源机制求解构造应力场的网格搜索法[J].国际地震动态,2012(6):19. [12] 高名修.华北块断构造区的现代引张应力场[J].地震地质,1979,1(2):1-12. [13] 李钦祖.华北地壳应力场的基本特征[J].地球物理学报,1980,23(4):376-388. [14] 李孟銮.鄂尔多斯块体周围的地震活动与构造[J].西北地震学报,1985(S1):1-9. [15] 李孟銮,赵知军.宁夏地区现代构造应力场及其与地震活动的关系[J].地震研究,1986,9(3):299-314. [16] 赵知军,刘秀景.宁夏及其邻区地震活动带与小区域构造应力场[J].地震地质,1990,12(1):31-46. [17] 姜家兰.陕西及其邻近地区现代构造应力场[J].西北地震学报,1991,13(4):85-88. [18] 刘巍, 赵新平, 安卫平.太原盆地的应力场特征[J].山西地震,1994(1):18-24. [19] 刘巍,孟雁英,王赵丽.大同盆地现今构造活动及地壳应力场特征[J].山西地震,1995(1):7-13. [20] 汪素云,俞言祥.震级转换关系及其对地震活动性参数的影响研究[J].震灾防御技术,2009,4(2):141-149. [21] Gephart J W, Forsyth D W. An improved method for determining the regional stress tensor using earthquake focal mechanism data: Application to the San Fernando earthquake sequence[J].J Geophys Res,1984,89:9305-9320. [22] Michael A J.Stress rotation during the Coalinga aftershock sequence[J].J Geophys Res,1987,92:7963-7979. [23] 盛书中,万永革,徐志国,等.由地震释放的地震矩叠加推导平均应力场[J].地震地质,2013,35(1):92-100. -
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