遥感在宁夏贺兰山东北段1∶50000区域地质调查中的应用研究

摘要

以 SPOT5及 ETM+影像为基础数据，采用3D GIS遥感技术，通过对研究区岩性地层、线性构造、环形构造等地质体的遥感影像特征系统总结，结合野外调查，建立岩性地层及构造解译标志，对宁夏贺兰山东北段1∶50000区域地质调查工作区进行遥感地质解译。解译结果表明：研究区西部多被贺兰山岩群和古元古代花岗岩覆盖，中部及东南部大部分为第四系和新近系地层；东部石峡谷、黑龙贵及老石旦镇地区，主要出露地层有奥陶系及寒武系；研究区构造发育，主要分布在西部贺兰山基岩区，共解译出线性构造113条，以 NEE向和近 SN向线性构造最为发育，线性构造相互切割，形成“块状”特征；环形构造33个，在区域上总体呈 SN向条带状分布；褶皱4处，均为紧密型褶皱组合；不整合界线1条；总体呈“西部构造发育，局部呈块状，东西差异明显”的特点。实践表明，在1∶50000区域地质调查中应用遥感和 GIS相结合的方法，对提高区域地层构造认识以及遥感解译精度有较大帮助，能有效提高填图质量和工作效率，在区域地质调查工作中有良好的应用价值。%This paper summarized the characteristics of the remote sensing images of geological bodies like li-thological strata,linear structure and circular structure by applying 3D GIS remote sensing technique and u-sing SPOT5 and LANDSAT ETM+ images as basic data.Combined with results of field survey,and based on establishment of interpretation marks for lithological strata and structure,the paper conducted remote sensing geological interpretation in the 1∶50,000 scale regional geological survey area in the northeast sec-tion of Helan Mountain of Ningxia.The results of interpretation indicated that:the west part of the study area was covered by Helanshan rock groups and Paleoproterozoic granite,and most of the middle section and southeast section was strata of Quaternary and Neogene System;outcropped strata in Shixiagu,Heilonggui and Laoshidanzhen area in the east was in Ordovician and Cambrian System;structures were developed in in the study area and were mainly distributed in Helanshan Bedrock Area in the west,and a total of 113 linear structures were interpreted,among which NEE-trending and nearly SN-trending linear structures were the most well-developed ones,and intersected linear structures were characterized by “massive form”;a total of 33 circular structures were distributed along SN direction in the form of belt in this area;all of 4 folds in this area were close-type fold groups;there was only 1 unconformity boundary in this area;the whole area could be described as “well-developed western part,massive form in parts and obvious difference between east and west”.Practice indicated that application of both remote sensing and GIS was of great practical value in re-gional geological survey and it greatly helped our understanding of regional strata and structures and im-proved interpretation accuracy of remote sensing as well as quality and efficiency of geological mapping.