322地区SBZ铀矿床地质特征及成矿条件分析

Geological Characteristics and Mineralization Conditions of the SBZ Uranium Deposit in the 322 Area

SBZ铀矿床位于我国重要铀矿田之一的322地区花岗岩体外接触带。寒武系下统香楠组上段(1x3)富含有机质和黄铁矿的泥质灰岩、含炭硅板岩、结晶灰岩组合层是其主要的赋矿层位,遂川-热水深断裂的次级断裂构造F23号带控制着该矿床铀矿体的定位空间,粉红色碳酸盐化(方解石化)与铀矿化关系极为密切。矿体呈似层状、脉状、透镜状产出,其产状与地层及控矿断裂构造产状基本一致。矿区内放射性物化探异常明显,地表伽马场发育,出露面积0.24km2,具明显的富集中心,轴向明显,并严格受F23号断裂带组控制;放射性水化学异常晕圈规模大、晕级完整、形态规则,其长轴方向与控矿构造一致,并受其控制。SBZ铀矿床成矿年龄为54Ma,成矿温度112℃～250℃,属中低温热液叠加层控改造型。

The SBZ uranium deposit lies in the outside contact zone of Lujing granite.Argillaceous limestone carboncaceous-siliceous slate and crystalline limestone,rich in organic matter and sedimentary pyrite of the upper Xiangnan Group of Cambrian is one of primary hosting rock beds.Many orebodies of the SBZ uranium deposit were controlled by F23,the secondary fault of the major Suichuan-Reshui fault zone.Pink carbonatization is closely related with the uranium mineralization.Uranium orebodies are of layer-like,vein or lenticular,with occurrence almost same as the strata.There exist obvious anomalies of geochemical exploration and the ground gamma-ray field with an exposed area of 0.24km2 and an obvious enrichment center in the SBZ uranium deposit,which has an distinct axis controlled by structure F23.Moreover,radiohydrological anomalies of the SBZ uranium deposit are of great scale,complete,and regular,of which the long axis is consistent with the ore-controlling structure.The uranium ore-forming age of the SBZ uranium deposit is 54Ma,with ore-forming temperature 112℃～250℃,and the genesis belonging to the mesothermal-epithermal hydrothermal superimposed transformation type.