摘要
在深地震测深（DSS）资料约束下，使用做过地形校正的重力资料对太行山山前地区的深部构造进行研究。在4条测线上通过分层剥离的方法分别得到沉积层和莫霍面的空间图像以及深部密度界面的形态分布特征。研究结果表明，在太行山山前断裂带两侧地壳结构明显不同，西面高原地区沉积层较薄，平均在4km以下；东侧华北平原地区多数在5km以上，且起伏剧烈，对应于华北平原地区一系列次级的凹陷与隆起构造。莫霍面和康氏面在两侧均相对平缓，康氏面从东部的大约18km增加到西北部山区的28km左右；莫霍面深度从东南侧平原地区的大约34km左右向西北侧埋深陡然增加到42—43km。太行山断裂带表现为太行山重力梯级带，并在太行山山前地壳内各界面均发生错断，莫霍面和康氏面错断距离达4—5km，这还证明太行山山前断裂带的确是深大断裂。
Using the Bouguer gravity anomaly data with topographic correction, the investigation of deep structure in the piedmont fault zone of Taihang Mountain area is done. Based on the Geosoft software processing platform, we use the GM-SYS gravity inversion module for gravity inversion with the constraint of Deep Seismic Sounding （DSS ） profile results which completed in the last two decades. From the four lines of gravity measurement in Taihang Mountain region, the crustal densit） structure in the piedmont fault zone is gotten and the three-dimensional gravity profiles are drawn by interpolation method. The gravity inversion shows that the Conrad and Moho discontinuities increase northwestward gradually from 18 km and 34 km in the eastern coast plain to 28 km and 43 km in the northwest Taihang Mountain, respectively. Both discontinuities deepens abruptly when crossing NNE-trending Taihang zone, indicating that the piedmont thrust fault of Taihang Mountain could extend deep cutting through the Moho. The sediment thickness is generally less than 3 km in mountainous region, but is much thicker （3 - 10 km） over North China rift basins with variations on a series of second - order NNE depression and upheaval structures. The results are basically concordance with the previous studies in this area.
出处
《西北地震学报》
CSCD
北大核心
2008年第4期305-309,共5页
Northwestern Seismological Journal
基金
湖北省教育厅科学技术研究项目(G20081206)
国家自然科学基金项目(40774074)
关键词
太行山
重力梯级带
莫霍面
布格重力异常
地震
Taihang Mountains
Gravity gradient zone
Moho discontinuity
Bouguer gravityAnomalies
Earthquake
