砂岩型铀矿综合探测技术和实践—以二连盆地BYH铀矿为例

Comprehensive exploration techniques and Practices for Sandstone type uranium deposit:a case study of BYH uranium deposit in Erlian Basin

【研究目的】砂岩型铀矿作为全球最重要的铀矿类型和我国最主要的经济可采类型。多种探测技术方法的综合运用是查明盆内砂岩型铀储层结构、构造、含铀砂体空间分布以及预测铀矿体延伸展布的有效手段。二连盆地砂岩型铀矿总体具有埋藏浅,古河谷近源成矿,带状集中分布特征,因地制宜建立该类型盆地的砂岩型铀矿综合探测技术方法对找矿勘查具有重要借鉴意义。【研究方法】以二连盆地川井坳陷BYH铀矿为研究对象,对重力、航磁、电法、地震、钻井、氡气和伽马总量等多种信息进行提取和地质解释,建立综合探测技术方法组合。【研究结果】提出了“重磁寻隆凹、电井震找断砂、氡伽圈异常”分层次综合探测组合模式;以航磁、重力信息来探寻隐伏、半隐伏岩体和基底的隆凹展布形态,确定区域成矿有利构造;然后利用高密度电阻或音频大地电磁开展铀储层高阻中的相对低阻异常特征分析,结合二维地震剖面精细刻画铀储层结构和断裂构造特征,分析含矿砂体空间展布;利用氡气和伽马总量或能谱测量圈定异常晕,分析其与深部铀矿体的空间位置关系,判断铀矿体的延伸展布。【结论】建立二连盆地砂岩型铀矿综合探测技术组合,结合成矿地质条件,能够指导区域砂岩型铀矿找矿勘查和部署。

This paper is the research of uranium deposits.[Objective]Sandstone-type uranium deposits are the most important type of uranium deposits globally and the most economically recoverable type in China.The comprehensive application of various exploration techniques is an effective means of identifying the structure and composition of sandstone uranium deposits in the basin,the spatial distribution of uranium-bearing sands,and predicting the extension of uranium ore bodies.Sandstone-type uranium deposits in the Erlian Basin are generally characterised by shallow burial,paleovalley type mineralization with near-source and concentrated distribution in zones,and the establishment of comprehensive sandstone-type uranium mine detection technology methods in this type of basin according to local conditions is an important reference for prospecting and exploration.[Methods]Taking the BYH uranium deposit in the Chuanjing depression of the Erlian Basin as the research object,we extracted and geologically interpreted a variety of information such as gravity,aeromagnetism,electrical prospecting,seismicity,drilling,radon gas and gamma measurement,and established a combination of integrated detection technology.[Results]The combined model of"heavy magnetic search for rumbles,electric well seismic search for fractured sands,and radon and gamma circle anomalies"is proposed,aeromagnetic and gravity information will be used to explore the rumble and concave spreading patterns of concealed and semi-concealed rock bodies and basement,and to determine the favourable structures for regional mineralisation;then high-density electric resistance or audio geomagnetic sounding will be used to carry out the analysis of anomalous features of high resistance and low resistance uranium reservoirs.Then,high-density electrical resistance or audio geomagnetic analysis is used to analyse the characteristics of the anomaly,combined with 2D seismic profiles to finely delineate the structure of uranium reservoirs and fracture tectonic features,and to analyse the spatial distribution of orebearing sands;and radon gas and gamma total or spectral measurements are used to define the anomaly halo,analyse its spatial location in relation to the deep uranium ore bodies,and assess the extension of the uranium ore bodies.[Conclusions]Establishment of a comprehensive exploration technology combination for sandstone-type uranium deposits in the Erlian Basin,combined with the geological conditions of mineralization,is capable of guiding the exploration of regional sandstone-type uranium mines.