郯庐断裂带中南段应力场及变形特征
Characteristics of Regional Stress Field and Latest Crustal Deformation in Middle-southern Segment of Tan-Lu Fault Zone

收集郯庐断裂带中南段及附近区域2009年以来的小震初动资料，利用格点尝试法求得51个台站的综合机制解和167次小震的震源机制解，采用Michael的应力张量求解方法获得区域应力场分布；同时利用震源机制三角形分类方法，对51个台站综合机制解的变形形式进行分类，探讨其空间分段特征。结果表明：研究区域的主压应力方向以NEE和近EW向为主，沿郯庐断裂带中南段由北往南，主压应力方向由NEE向逐渐偏转为近EW向；郯庐断裂带中南段变形特征存在局部差异，山东段以走滑型机制为主，兼有部分正断层震源机制；江苏段及安徽北段，郯庐断裂带带内及其东侧集中表现为逆冲断层类型，西侧则以走滑型为主；安徽段南端，郯庐断裂带东西两侧，震源机制分别以走滑型和正断型机制为主。
In this study, we collected the P-wave first motion data of small earthquakes that have occurred in the middle-southern segment of the Tan-Lu fault zone since 2009. We used the grid point test method to obtain the integrated mechanism solutions of small earthquakes recorded by 51 stations and the focal mechanical solutions of 167 moderate and small earthquakes. The results show that the direction of the principal compressive stress is close to NEE and nearly EW in the study area and that there are local differences in the crustal deformation in the middle-southern segment of the Tan-Lu fault zone. The segmental characteristics of the regional deformation, as reflected by composite mechanism solutions for different station types, have a close correlation with the tectonic background and stress field in the study area..