江西省乐安县相山矿田荷上铀矿床蚀变特征及其意义

荷上铀矿床赋存于花岗斑岩体的内外接触带,围岩为火山熔岩及陆相碎屑沉积岩、基底变质岩。矿体受裂隙密集带控制,空间上与花岗斑岩密切相关。详细研究了荷上铀矿床的围岩蚀变特征,并将该矿的蚀变和成矿过程划分为三个阶段,即铀-赤铁矿成矿阶段,铀-萤石化-绿泥石-水云母化阶段和铀-碳酸盐成矿阶段,其中第二阶段为主要成矿阶段。提出岩石的褪色蚀变(以浅色矿物蚀变为主,另见绿泥石化、黄铁矿化等)对成矿有间接指示意义,而长石变红、石英变黑、粉末状紫色萤石化、磷灰石化等蚀变则对铀成矿有直接指示意义。在分析荷上铀矿床蚀变特征的基础上,提出该区下一步工作建议。

Uranium Mineralization Alteration in Heshang,Xiangshan Ore-field,Lean Jiangxi Province

The uranium deposit of Heshang occurred in the internal and external contact zone.The ore-bearing rock is volcanic lava,terrestrial clastic sedimentary rocks and metamorphic basement.The ore-body is controlled by fissure zone and related with granite-porphyry in spatial.In this study,the characteristic of wall-rock alteration is introduced.In addition,the process of alteration and mineralization are divided into three stages,i.e.mineralization of uranium-hematite,uranium-fluorite-chlorite-hydromicatization,and uranium-carbonate.And the main mineralization is uranium-fluorite-chlorite-hydromicatization.The fading alteration(mainly in light-color mineral together with chloritization and pyrite) is proposed in this study,which has indirect indication for mineralization.The red feldspar,black quartz,purple fluorite-based powder is direct indicator of uranium mineralization.The further work plan is proposed based on uranium deposit alteration of Heshang.