南天山中、新生代造山作用与萨瓦甫齐铀矿床叠加富集效应  

Meso-Cenozoic Orogeny in South Tianshan and the Resultant Superimposed Enrichment Effect on the Sawafuqi Uranium Deposit

作　　者：刘章月[1] 秦明宽[1] 刘红旭[1] 蔡根庆[1] 何中波[1] 郭强[1] 许强 宋继叶[1] 

机构地区：[1]核工业北京地质研究院,北京100029

出　　处：《地质学报》2016年第12期3310-3323,共14页Acta Geologica Sinica

基　　金：国家重点基础研究发展计划"973"项目(2015CB453004);基础地质调查项目(231221000000151201);国防预研项目(3210402)联合资助成果

摘　　要：天山造山带中、新生代陆内造山过程对天山山间盆地和两侧盆地内的砂岩型铀矿有明显的控制作用。本文系统采集萨瓦甫齐铀矿床矿石样品,通过薄片镜下观察、α径迹放射性照相、电子探针和扫描电镜等多种技术手段,识别出萨瓦甫齐铀矿床三种矿化类型:含铀碎屑原生沉积型铀矿化、层间氧化带型铀矿化和由低温热液脉型铀矿化。三种铀矿化具有明显的先后形成顺序,原生沉积型铀矿化形成了矿区早期铀预富集,层间氧化带铀矿化构成了本区主要铀矿体,而晚期低温热液脉型铀矿化则是对前期铀矿体的叠加富集。结合南天山中、新生代造山作用指出,三叠纪隆升作用形成了萨瓦甫齐铀矿床原生沉积型铀矿化;始新世-渐新世相对稳定的构造环境形成了层间氧化带型铀矿化;中新世开始,伴随天山强烈褶皱造山,来自深部的造山热液改造了前期铀矿体,形成了低温热液脉型铀矿化叠加富集。Meso Cenozoic intracontinental orogenic process in the Tianshan orogenic belt has a significant controlling effect on the sandstone type uranium deposits in the intramontane and bilateral basin. This study carried out the systematic analysis of the samples from Sawafuqi uranium deposit using thin section observation, α track radioactive graph technique, electron probe and scanning electron microscope. The results show that the Sawafuqi uranium deposit occur as tabular, lamellar, quasi lamellar, lens like ore bodies, with high ore grade in the South Tianshan orogenic belt, which is different from typical interlayer oxidation zone sandstone type uranium deposit. The three mineralization types have been identified in the deposit： preliminary sedimentary mineralization, interlayer oxidation zone type uranium mineralization, and epithermal vein type uranium mineralization. Three uranium mineralization presents obvious formation sequence, with the preliminary sedimentary uranium mineralization forming early uranium enrichment, interlayer oxidation zone uranium mineralization forming the main orebodies, followed by late superimposed enrichment by the late stage epithermal uranium mineralization. Combined with previous study of the Meso Cenozoic orogeny in South Tianshan, it can be concluded that preliminary sedimentary type uranium mineralization of the Sawafuqi uranium deposit was caused by Triassic Tianshan uplifting; interlayer oxidation zone type uranium mineralization occurred in a relatively stable tectonic setting in the Eocence Oligocene period; and since the Miocene, orogenic hydrothermal solution derived from strong folding and orogeny of South Tianshan reformed the former uranium ore bodies, thus resulting in the superimposed enrichment of epithermal vein type uranium mineralization.

关 键 词：南天山 陆内造山 造山热液 叠加富集 萨瓦甫齐铀矿床 

分 类 号：P619.14[天文地球—矿床学]