摘要
鄂尔多斯盆地北缘是我国重要的砂岩型铀矿床基地,近几年地质勘查发现特拉敖包地区有很大的找矿潜力,定位氧化还原过渡带是圈定有利成矿地区的关键。前人针对砂岩型铀矿开展的磁法研究大多只是直接对矿床的磁异常进行简单分析,很少研究不同环境磁化率差异,也未考虑深部基底磁性的影响。文章统计了研究区不同砂体磁化率参数,计算了理论模型正演响应,并开展磁法测量,获得了磁异常特征并求取剩余磁异常,其结果与氧化还原过渡带位置,以及三价铁与二价铁比值有一定的对应关系。认为研究区氧化还原过渡带上方表现为微弱高异常特征,与传统层间氧化带型磁异常形态有区别,原因是后期油气还原作用使局部铁元素价态发生变化,引起局部磁异常升高。
The northern margin of Ordos Basin is an important base for sandstone-type uranium deposit in China.In recent years,geological exploration has found that the Telaaobao area has great prospecting potential.How to locate the redox transition zone is the key to delineate favorable metallogenic areas.Most of the previous magnetic studies on sandstone-type uranium deposits only directly analyze the magnetic anomalies on the deposits,and rarely study the difference of magnetic susceptibility in different environments,nor concern the influence of deep basement.In this paper,the magnetic susceptibility parameters of different sandstones in the study area are counted,the forward response of the theoretical model was calculated,and the magnetic measurement was carried out to obtain the magnetic anomaly characteristics and the residual magnetic anomaly.The results have found some relationship between the location of the redox transition zone and the ratio of ferric iron to ferrous iron.It was considered that the redox transition zone in the study area was characterized by weak high anomaly,which is different from the traditional interlayer oxidation zone type magnetic anomaly.The reason was believed that the oil and gas reduction in the later period changed the valence state of local iron elements and caused the local magnetic anomaly to rise.
作者
陈聪
程纪星
周俊杰
吴国东
CHEN Cong;CHENG Jixing;ZHOU Junjie;WU Guodong(CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology,Beijing Research Institute of Uranium Geology,Beijing 100029,China)
出处
《铀矿地质》
CAS
CSCD
2024年第2期301-308,共8页
Uranium Geology
基金
国家重点研发项目“煤系战略性金属矿产精细勘查技术与协同勘探模型”(编号:2021YFC2902004)资助。
关键词
磁异常
正演计算
砂岩型铀矿
氧化还原过渡带
特拉敖包矿产地
magnetic anomaly
forward calculation
sandstone-type uranium deposit
the redox transition zone
Telaaobao Occurrence
