贵州织金磷块岩结构及其沉积环境  

Structures and Sedimentary Environment of Phosphorite in Zhijin County, Guizhou Province, China

作　　者：刘洁[1,2] 温汉捷[1] 刘世荣[3] 樊海峰[1] 张羽旭[1] 

机构地区：[1]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳550002 [2]中国科学院大学,北京100049 [3]中国科学院地球化学研究所环境地球化学国家重点实验室,贵州贵阳550002

出　　处：《矿物学报》2016年第2期253-259,共7页Acta Mineralogica Sinica

基　　金：科技部"973"项目(编号:2014CB440904);国家自然科学基金(批准号:40930425;41173026;41273024);中国科学院国家外国专家局创新团队国际合作伙伴计划"陆内成矿作用研究团队"(KZZD-EW-TZ-20);中国科学院矿床地球化学国家重点实验室"十二五"项目群(编号:SKLODG-ZY125-07);中国科学院西部之光重点项目(2014)

摘　　要：贵州织金磷矿为一超大型含稀土磷矿床,产于早寒武世梅树村期底部含磷岩系。本文在分析该磷矿矿石化学组成、矿物组合的基础上,重点针对磷块岩的结构特征进行扫描电子显微镜和电子探针微区分析,发现在纵向上:上段硅质磷块岩结构类型包含泥晶结构、内碎屑结构、无定形结构和少量生物屑结构,其结构成熟度较低,沉积水体较深,属于宁静的半局限海/浅海沉积环境;而下段白云质磷块岩结构类型包含内碎屑、无定形结构和较多生物屑结构,其结构成熟度较高,水动力作用较强,沉积水体较浅,属于动荡的滨海沉积环境。横向上,织金戈仲伍组与滇东渔户村组大海段在地层年代上相互对应,两处的磷块岩系所含的结构类型相似,只是各种结构类型所占比例不同。此外,结合其他沉积环境指标,发现织金磷矿沉积于弱氧化―贫氧的滨海向浅海过渡的环境。The early Cambrian phosphorite deposit in the Gezhongwu Formation, Zhijin County, Guizhou Province, P.R. China is a super large ore deposit combined with phosphorus and REE. Based on the analysis of the chemical and mineral composition of this phosphorus rock series, we focus on the analysis of the phosphorite structures＇ characteristics using scanning electron microscope（SEM） and electron probe microscopic analyzer（EPMA）. Vertically, it shows that the upper section of silicious phosphorite possesses mud-crystalline structure, clastic structure, amorphous structure and bioclastic structure with lower maturity and sea water from a relatively deep level; and that the lower section dolomitic phosphorite bore clastic structure, amorphous structure and bioclastic structure with higher structure maturity, a stronger hydrodynamic effect and sea water from a relatively shallow level. Horizontally, the Gezhongwu Formation corresponds with the Yuhucun Formation in stratigraphic chronology, both of which have the same structural characteristics. In addition, combined with other sedimentary environment redox indexes, it indicates that the phosphorite deposit formed in the suboxic-anoxic waters and evolved in an environment that was from the coast to a shallow sea.

关 键 词：贵州 织金 早寒武世 磷块岩结构 沉积环境 

分 类 号：P612[天文地球—矿床学] P619.2[天文地球—地质学]