鄂尔多斯盆地西南部环县地区砂岩型铀矿成矿要素遥感识别  

Remote sensing identification of metallogenic elements of sandstone-type uranium deposit in Huanxian area,southwest Ordos basin

作　　者：杨云汉 叶发旺[1] 木红旭 武鼎[1] 杨国防[1] 李新春[1] 淦清清 YANG Yunhan;YE Fawang;MU Hongxu;WU Ding;YANG Guofang;LI Xinchun;GAN Qingqing(National Key Laboratory of Science and Technology on Remote Sensing Information and Image Analysis Beijing Research Institute of Uranium Geology,Beijing 100029,China)

机构地区：[1]核工业北京地质研究院遥感信息与图像分析技术国家级重点实验室,北京100029

出　　处：《世界核地质科学》2024年第3期573-583,共11页World Nuclear Geoscience

基　　金：核能开发项目(编号:[2021]88)资助。

摘　　要：鄂尔多斯盆地是中国重要的能源、矿产产出盆地,先后在盆地北缘发现多个大型砂岩铀矿床,但是在盆内坳陷的铀矿勘查上仍需突破。渗出理论的提出为盆缘找矿向盆内找矿提供了新的理论依据。研究表明:断层、次生还原矿物、磁异常的变化以及地表铀异常信息是渗出成矿作用在浅表的反映。对上述信息的识别可以为盆内砂岩型铀矿勘查提供数据支撑。以鄂尔多斯盆地西南部环县地区为研究区,利用ETM影像、航磁数据进行构造解译,利用ZY1E高光谱影像识别区内主要出露蚀变矿物,结合航磁、航放数据进行综合分析。结果表明:研究区内断层主要表现为NE、NNE走向,其次为NW和SN向,主要出露蚀变矿物为伊利石、碳酸盐岩,主要分布在沿断层与河流下切作用出露的下白垩统岩层中。航磁异常资料显示研究区出现多处磁异常的过渡区,表现为正的弱异常,可能与深部还原性流体的渗出有关。航放数据表明铀的富集与断层、蚀变矿物的分布在空间上有一定关系。综合高光谱影像、航磁航放资料识别出红杂色沉积建造中铀成矿有利的构造与蚀变矿物,在环县地区指出4处找矿有利区,对坳陷内部找矿具有指导意义。Ordos basin is an important energy and mineral producing basin in China.Several large sandstonetype uranium deposits have been discovered at in the northern margin of the basin,but breakthroughs are still needed in the exploration of uranium deposits in the basin depression.The exudation theory provides a new theoretical basis for the uranium exploration from the basin-edge to intra-basin.Correlational studies indicate that the faults,secondary reduction minerals,magnetic anomaly and the information of uranium anomaly are the reflection of exudative mineralization on the surface.The identification of the above information can provide data support for the exploration of sandstone-type uranium deposits.ETM images and aeromagnetic data,structural interpretation and ZY1E hyperspectral image were used to identify the major exposed altered minerals in the Huanxian area in the southwestern Ordos basin,combined with aeromagnetic and aerial radioactivity data,a comprehensive analysis was carried out.The results show that the main faults in the study area are NE and NE strike,followed by NW and S-N strike.Illite and carbonate minerals are the main exposed alteration minerals,which are mainly distributed in the Lower Cretaceous strata exposed along the fault and river undercuts.The aeromagnetic anomaly data show that there are many transition regions with weak positive anomalies,which are related to the exudation of deep reductive fluids.The airborne data show that the enrichment of uranium is related to the distribution of faults and altered minerals in space.Based on the hyperspectral imaging,aeromagnetic and aerial radioactivity data,the favorable structures and altered minerals for uranium mineralization in the red-variegated sedimentary formation have been identified,and four favorable prospecting areas in Huanxian area have been pointed out,which are of guiding significance for prospecting in the interior of the depression.

关 键 词：遥感技术 鄂尔多斯盆地 砂岩型铀矿 渗出型成矿作用 红杂色沉积建造 

分 类 号：P627[天文地球—地质矿产勘探] P628[天文地球—地质学]