赣东北马荃盆地铀矿成矿机理探讨

Discussion on uranium mineralization mechanism in Maquan basin of northeast Jiangxi province

本文通过对马荃盆地铀矿床地质特征、矿体特征和含矿熔岩地球化学特征分析,认为成矿前富钠的碱性流体在辉绿岩的引领下进入孔隙度较高的角砾粗安岩,发生钠交代作用,并使角砾粗安岩中的铀活化、预富集,提供了部分成矿物质;成矿期富钾的碱性流体由玄武岩引领上升,沿断裂构造进入矿区,在破碎-裂隙带发育钾交代作用,该流体富磷,具还原性,其携带的深部矿质是该区成矿物质的主要来源。深部矿质叠加在成矿前铀预富集部位之上,在有利的空间形成又富又大的工业矿体。因此,马荃盆地铀矿床应属热液型铀矿床,重建了矿床成矿模式。

This article through to Maquan basin uranium deposit geological characteristics,ore body characteristics and the analysis of geochemical characteristics of ore lava,see rich sodium alkaline metallogenic fluid under the lead of diabase into the higher porosity breccia coarse andesite,sodium metasomatism occurs,and makes the breccia activation,preliminary enrichment of uranium in coarse andesite,provided some ore-forming materials;During the metallogenic period,the potassium-rich alkaline fluid rose from basalt and entered the mining area along the fault structure.Potassium metasomatism developed in the fracture--fracture zone.The fluid was phosphorous-rich and reductive,and the deep mineral materials it carried were the main source of metallogenic materials in this area.The deep ore superimposed on the pre-uranium enrichment site and formed rich and large industrial ore bodies in favorable space.Therefore,the uranium deposit in the Maquan basin belongs to hydrothermal uranium deposit,which reconstructs the metallogenic model of the deposit.