地球学报Issue(3)：329-337,9.DOI:10.3975/cagsb.2014.03.08
鄂尔多斯盆地东胜砂岩型铀矿床成矿水化学过程探讨
The Water-rock Interaction Process of the Dongsheng Sandstone-type Uranium Deposit, Ordos Basin
摘要
Abstract
In order to investigate the relationship of the hydrochemical process to the uranium metallogenic mechanism of the Dongsheng uranium deposit in Ordos basin, the authors conducted contrastive mineralogical and REE geochemical analysis of non-mineralized samples in the oxidation zone and mineralized samples in the redox transitional zone by means of general slice, electron microprobe, clay mineral X-diffraction, SEM and chemical testing. Mineralogical studies show that argillic alteration and sericitization of plagioclase can be observed in all samples, and coffinite is the main uranium mineral and is always adsorbed by fragments or carbon dust. Another interesting phenomenon is that the mineralized samples in the redox transitional zone contain more carbon dust and carbonate than those in the oxidation zone. Geochemical studies indicate that non-mineralized samples in the oxidation zone and low mineralization samples in the redox transitional zone show flat REE patterns in PAAS-normalized rare earth element plots. However, samples with high uranium content in the redox transitional zone show two different REE patterns: samples with carbon dust show a MREE enrichment pattern and those with carbonate show a HREE enrichment pattern. Mineralogical and geochemical differences of samples from different zones indicate that aqueous chemical reaction is the main uranium mineralization rather than carbon absorption. In the aqueous chemical process, CO32-which prefers combining UO22+and HRE3+is the main inorganic complex anion in the mineralized hydrothermal water, and argillic alteration and sericitization of plagioclase with Ca2+and SiO44-play an important role in the metallogenic process.关键词
鄂尔多斯盆地/砂岩型铀矿/水化学过程/铀成因机理Key words
Ordos Basin/sandstone-type uranium deposit/hydrochemical process/uranium mineralization分类
天文与地球科学引用本文复制引用
吴兆剑,易超,韩效忠,祁才吉,惠小朝..鄂尔多斯盆地东胜砂岩型铀矿床成矿水化学过程探讨[J].地球学报,2014,(3):329-337,9.基金项目
本文由国家高技术研究发展计划(863计划)项目(编号:2012AA061801)资助。 （863计划）
