纳米比亚欢乐谷地区白岗岩型铀矿成矿机理剖析

发布时间：2018-04-04 11:40

本文选题：成矿机理　切入点：成矿模式　出处：《高校地质学报》2017年02期

【摘要】：文章对纳米比亚欢乐谷地区白岗岩型铀矿的铀矿物学、成矿期次、主要控矿因素、成矿物质来源及成矿机理等进行了系统的研究,认为白岗岩型铀矿受到构造、岩性、地层、基性岩脉和后期热液活动等因素的综合控制。矿体主要产于褶皱的拐弯处、穹窿边缘及构造变异(转折、膨大)部位,这些构造为铀矿化提供了充足的赋存空间;同时千岁兰区域性断裂为铀的活化迁移提供了通道;在岩性方面,矿化白岗岩具有专属性,只有D、E型白岗岩成矿,其他类型白岗岩不成矿,而且矿化白岗岩主要侵入于卡里毕比组和卡塞布组;后期流体也对铀成矿具有叠加改造作用,该期铀矿化与侏罗纪基性岩浆的侵入密切相关。另外经研究发现,白岗岩型铀矿主成矿期铀来源于富铀的前达马拉基底,热液叠加改造期的铀可能来自于原生铀矿物本身,据此构建了一个全新的四阶段三期的"四维"成矿模式。
[Abstract]:In this paper, the uranium mineralogy, metallogenic stage, main ore-controlling factors, ore-forming source and metallogenic mechanism of the Baigangyan type uranium deposit in Huanle Valley area, Namibia, are systematically studied. It is considered that the Baigangyan type uranium deposit is subjected to structure, lithology and formation.Comprehensive control of basic vein and hydrothermal activity in late stage.The orebody mainly occurs at the bend of the fold, the margin of the dome and the position of tectonic variation (transition, enlargement), these structures provide ample space for uranium mineralization, and the regional faults of thousand years old provide a channel for the activation and migration of uranium.In the aspect of lithology, the mineralized Baigang rock has a special attribute, only the DGE-type Baigang rock is metallogenic, and the other types of Baigang rock are not metallogenic, and the mineralized Baigang rock mainly intrudes into the Karibibi formation and the Casebuk formation.The late fluid also has superimposed and modified uranium mineralization, which is closely related to the intrusion of Jurassic basic magma.In addition, it has been found that the uranium in the main metallogenic period of the Baigangyan type uranium deposit originated from the pre-Damara basement rich in uranium, and that the uranium during the hydrothermal superposition transformation period may come from the primary uranium ore itself.Based on this, a new four-stage and three-stage "four dimensional" metallogenic model is constructed.
【作者单位】：核工业北京地质研究院;中核铀资源勘查与评价技术重点实验室;
【基金】：非洲中南部古老地块铀矿综合识别评价技术及应用研究项目
【分类号】：P619.14

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