层间氧化带边界类型划分与铀成矿潜力评价  

THE DIVISION OF INTERL FORMATION OXIDIZED ZONE MARGINS AND APPRAISE OF THE URANIUM MINEROGENIC CAPACITY

作　　者：权志高 

机构地区：[1]核工业研究所,陕西咸阳712000

出　　处：《地质找矿论丛》2003年第4期225-228,共4页Contributions to Geology and Mineral Resources Research

基　　金：中国地质调查局国土资源大调查项目(200010100001)资助。

摘　　要：　层间氧化带型铀矿床只与特定背景条件下形成的部分层间氧化带有关,铀元素沉淀富集于层间氧化带前锋线及其附近;在该区域地球化学性质完全不同的氧化与还原介质相互作用;对于铀成矿作用来说,氧化作用的效果是十分重要的,可以通过采集目的层相同岩性在正常氧化带和正常原生带的样品,分析其铀含量比值,间接反映氧化作用使铀从围岩中带出的能力;铀是否成矿主要取决于层间氧化带前锋线还原障的还原能力,参照岩石原生地球化学类型划分原则,岩石还原能力可划分为强还原能力(C有机质>0.3%)、中等还原能力(C有机质0.05%～0.3%)、弱还原能力(C有机质<0.05%)3个等级;以反映岩石还原能力的有机质含量为横座标,以0.05%和0.3%分别作为划分弱中、中强还原能力的分界线:以反映氧化作用效果的U氧化/U还原为纵座标,以0.5和1分别作为氧化作用效果好与较好、较好与差的分界点:划分层间氧化带边界类型为9类:根据不同层间氧化带前锋线边界类型的成矿潜力差异,可作为对目标区进行层间氧化带型铀成矿潜力评价的依据。Interfomational oxidized zone type U-deposits are limited to the interformational oxidized zones formed in particular condition. U-element is enriched at the front of the oxidized zone or in its surroundings where the oxidized and reduced media react with each other. Oxidation is the key to U-ore formation. Analysis of samples from the normal oxidized zone and the primary sedimentary zone show indirect U-moblizafion from the wallrock and the ore formation mainly depends upon reduction capacity of the geochemical barrier. According to principle of the primary geochemical classification the rocks reduction capacity is divided into strong (organic carbon >0.3%), medium (organic carbon 0.05%~0.3%) and weak (organic carbon <0.05%). Oxidation degree is divided by values of 0.5 and 1 at the U-oxidation/reduction longtidinal coordination into effective oxidation and less effective oxidation. Based on the data the interformational oxidized zones are subdivided into 9 types. ore formation difference at the front is the basis to appraise the ore formation potential of the U-deposit.

关 键 词：层间氧化带 边界类型 成矿潜力 评价依据 铀矿床 

分 类 号：P619.14[天文地球—矿床学]