辽吉古裂谷三维地质结构重磁电综合解释  

GME Integrated Interpretation of 3D geological structure of Liao-Ji ancient rift based on geophysical data

作　　者：刘文玉[1] 李桐林[1] 薛林福[2] 柴社立[2] 胡英才[1] 范翠松[3] 李建平[4] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]吉林大学地球科学学院,长春130026 [3]中国地质调查局天津地调中心,天津300170 [4]山东科技大学地质科学与工程学院,青岛266590

出　　处：《地球物理学进展》2015年第2期516-523,共8页Progress in Geophysics

基　　金：中国地质调查局三维地质填图与深部地质调查试点项目"本溪-临江地区深部地质调查"(1212011220247);吉黑东部综合找矿方法研究(201301-060-004)联合资助

摘　　要：辽吉古裂谷的三维地质结构对于认识研究区的成矿规律,寻找隐伏矿体具有重要意义..本文首先分析了研究区内采集标本的密度、磁化率和电阻率三种物性资料,然后对4条非震地球物理剖面的数据进行了处理与反演,结合地质资料,对各剖面进行了综合地质地球物理解释,获得了如下结论：1）各主干断裂表现为明显的电性梯度带,切割深度为5~7 km;2）不同时代地层和岩体具有不同的地球物理特征,例如太古代变质岩系地球物理特征表现为＂三高＂.即密度大、磁性高、电阻率高,而古元古代辽吉花岗岩地球物理特征表现为密度较大、略带磁性、电阻率值较高的特点：3）古元古界在有些地方埋藏较深。如在草河口镇附近厚度大于10 km,其它地区厚度较小,且多被中新生代岩体侵位而残存于地表;4）侵入岩体与围岩地层的关系比较复杂,有些岩体存在继承性。有些岩体与地层相互叠置;5）辽吉古裂谷中央凹陷区以辽吉花岗岩为结晶基底.太古代结晶基底在该区域因后期改造而缺失.Three-dimensional geological structure Liao-ji Paleorift understanding of metallogenic regularity of the study area, looking for hidden ore body is important, This paper analyzes the density of the study area to collect specimens, magnetic susceptibility and resistivity of three physical property data, then the data four now shock geophysical profiles were processed with the inversion, combined with geological data, for each cross-section were integrated geological geophysical interpretation, obtained the following conclusions： 1 ） the performance of each of the main fault apparent electrical gradient zone, cutting depth of 5- 7 km~ 2） and rock formations of different ages have different geophysical characteristics, such as geophysical Archean metamorphic rocks characterized by the ＂three high＂, ie density, magnetic high, high resistivity, and Paleoproterozoic granites geophysical characteristics Liaoji showed denser, slightly magnetic, resistivity values representing characteristics of high ; 3 ） Paleoproterozoic buried deep in some places, such as the thickness of the grass near the mouth of the town more than 10 km, the smaller the thickness of other areas, and more are in the Cenozoic emplacement while remaining on the surface ; 4 ） intrusive rocks and rock formations of the relationship is more complex, the existence of some rock succession, with some rock formations overlap each other ; 5 ） Liaoji ancient rift zone in central depression Liaoji granite crystalline basement Arehean crystalline basement transformation in the region due to the late and missing.

关 键 词：综合解释 地球物理 三维地质结构 辽吉古裂谷 

分 类 号：P312[天文地球—固体地球物理学] P318[天文地球—地球物理学]