摘要
本文通过全区航磁数字处理结果,结合重力和人工地震测深资料,初步认为广西地壳具有四个分层-沉积岩层、变质岩层(浅磁源层)、花岗岩质层、玄武岩质层(深磁源层)。将磁场、地壳分层与历史地震资料对比,笔者总结了震源分布的若干规律:广西地震震源分布于浅磁源层内,震源分布有从桂东南向桂西北加深的趋势,与浅磁源层有类似的深度变化规律。在平面上震中集中分布于区域磁力高与磁力低的交接地带,或隆起区与拗陷区的交接地带。北西向断裂组是广西境内主要控震断裂组。笔者认为,重磁信息可为区域稳定性评价和地震预测提供依据,研究地震与磁场的关系有助于地震烈度小区划。
Based on airborne geomagnetic survey, gravitational and artificial earthquake, four subdivided layers have been recognized in Guangxi, i.e. the sedimentary rock layer, the metamorphic rock layer ( shallow geomagnetic focus layer) , the granitic layer and the basaltic layer (deep geomagnetic focus layer). Compared geomagnetic field and crustal layers with the historial earthquake, the distributional regularities of the earthquake focus have been summarized. These regularities are as follows.
The earthquake focus distributed in shallow geomagnetic focus and deepened gradationally from southeastern Guangxi to northwestern Guangxi, so do the shallow geomagnetic focus. The epicenter was mainly occurred on bordered region between high geomagnetic and low geomagnetic fields, or upwarping and downwarping regions. The major fault group controlled earthquakd was northwestern direction: In term of gravitational geomagnetic field, we may discuss the regional stabilization and earthquake prediction, and also distinguish earthquake intensity with relationship between earthquake and geomagnetic field.
