神农架地区阳日断裂深部地质结构研究——基于广域电磁法探测  

Study on Deep Geological Structure of Yangri Fault in Shennongjia Area:Based on Wide Field Electromagnetic Method Prospecting

作　　者：赵康 田碧 崔培龙 康昱 蒋臣 税顺建 姚郁松 靳锁锁 舒中华 Zhao Kang;Tian Bi;Cui Peilong;Kang Yu;Jiang Chen;Shui Shunjian;Yao Yusong;Jin Suosuo;Shu Zhonghua(Eighth Geological Brigade of Hubei Geological Bureau,Xiangyang,Hubei 441002)

机构地区：[1]湖北省地质局第八地质大队,湖北襄阳441002

出　　处：《资源环境与工程》2023年第6期641-647,共7页Resources Environment & Engineering

基　　金：湖北省地质局地质矿产项目“湖北省房县—南漳县地区页岩气调查评价”(KCDZ2023-34);湖北省地质局科技项目“襄枣凹陷中—新生代沉积构造演化及其多种能源矿产赋存效应”(KS2023-32)。

摘　　要：阳日断裂为南大巴山前陆褶冲带与上扬子地台褶皱区的分界线,其深部地质结构特征还不明朗。以阳日断裂穿过的阳日地区为研究区,布设了1条NNE向广域电磁法剖面,获得了该区地表至-3000 m标高范围的二维电性结构模型。结果表明,阳日断裂表现为中高阻背景下明显的北倾中低阻异常带,倾角为45°~73°;其南侧主要出露震旦系—志留系地层,由浅至深总体表现为中低阻—高阻—中低阻异常分带,推测分别为志留系碎屑岩、震旦系—奥陶系碳酸盐岩、深部褶皱构造的反映;北侧主要表现为高阻异常带,推测主要由神农架群石槽河组白云岩引起。阳日断裂南侧的龙马溪组地层表现为倾向N、倾角约25°的中低阻异常带,沿倾向延伸长度达3 km。研究成果可加深对阳日断裂发育特征的认识,并为阳日断裂下盘龙马溪组页岩气勘查工作提供依据。Yangri fault is the boundary between the South Dabashan fold-fault belt and the Yangtze fold belt,and its deep geological structure characteristics are not clear.Taking the Yangri area where Yangri fault passes through as the research area,one NNE-trending wide field electromagnetic profile was laid out,and a two-dimensional electrical structural model was obtained from the surface to the elevation range of-3000 m in the area.The results show that Yangri fault is characterized by an obvious north-trending middle-low resistance anomaly zone under the background of middle-high resistance,with an inclination angle of 45°to 73°.The Sinian-Silurian strata are mainly exposed on the southern of Yangri fault.From shallow to deep,the overall performance is medium-low resistance to high resistance and to medium-low resistance,which is speculated to be the reflection of Silurian clastic rocks,Sinian-Ordovician carbonate rocks and deep fold structure.The north side is mainly characterized by high resistance anomaly zone,which is speculated to be mainly caused by dolomite of Shicaohe Formation of Shennongjia Group.The Longmaxi Formation on the south side of Yangri fault shows a medium-low resistance anomaly zone with N-trending and a dip angle of about 25°,and the extension length is 3 km.The research results can deepen the understanding of the development characteristics of Yangri fault and provide a basis for the exploration of Longmaxi shale gas.

关 键 词：阳日断裂 深部地质结构 广域电磁法 龙马溪组 

分 类 号：P542.3[天文地球—构造地质学] P631.325[天文地球—地质学]