相山矿田荷上铀矿床地质特征及成因探讨

Exploration of Geological Characteristics and Genesis of the Heshang Uranium Deposit in the Xiangshan Ore Field

为了解荷上铀矿床的地质特征及成因,通过野外地质调查、岩矿鉴定、地球化学分析等方法对该矿床进行研究。结果表明,铀矿体主要产于花岗斑岩岩体上方流纹英安岩裂隙带中,矿化蚀变强烈,见紫黑色胶状萤石化、水云母化。单矿体最高品位为0.578%,平均品位为0.239%,铀镭平衡系数平均值小于0.9。矿石类型为铀赤铁矿型和铀萤石型,前者U与Th呈正相关性,后者U与Th、Mo、Ga、Pb呈明显正相关性。矿床成因可能是花岗斑岩侵入活动后期,流体压力增大,促发了斑岩体上方岩石的水力压裂作用,导致岩石中的铀等元素的活化、运移和沉淀富集。本研究成果可为荷上铀矿床深部及周边找矿提供依据。

In order to determine the geological characteristics and genesis of Heshang uranium deposit,the deposit was studied by means of field geological survey,rock and mineral identification,geochemical analysis and other methods.The results show that,uranium ore body is mainly produced in the rhyolitic-dacite fracture zone above the granite porphyry,with strong mineralization alteration,purple-black colloidal fluorization and damouritization.The highest grade of single ore body is 0.578%,the average grade is 0.239%,and the average value of uranium-radium balance coefficient is less than 0.9.The ore types are uranium-hematite and uranium-fluorite.U is positively correlated with Th in uranium-hematite,and U is more obviously positively correlated with Th,Mo,Ga and Pb in uranium-hematite ore.The genesis of the deposit may be due to the late intrusion of granite porphyry,which increased fluid pressure and promoted hydraulic fracturing of the rocks above the porphyry body,leading to activation,transport and precipitation enrichment of uranium and other elements in the rocks.The results of this research can provide foundation for searching the deeper part of the Heshang uranium deposit and the surrounding area.