地质与勘探2011，Vol.47Issue(2)：294-303,10.
昆阳磷矿沉积环境与矿床地球化学
Sedimentary Environment and Geochemistry of the Kunyang Phosphorite Deposit in Eastern Yunnan Province
摘要
Abstract
The Kunyang phosphorite deposit in eastern Yunnan Province is a large-scale one characterized by marine sediments, tectonically located at the southwestern margin of the ancient Yangtze block The Lower Cambrian Qiongzhusi Group (ε13q) outcropping widely in the ore district constitutes the roof rocks, which are also phosphor-bearing sedimentary formation. The Zhongyicun group (ε12z) containing phosphoric sedimentary formation and Xiaowaitoushan Group ( ε11x) are the bottom of P-bearing sedimentary formation. The Dengying Group (Zbdn) of Sinian System constitutes the Cambrian sedimentary basement, within which erosion planes are present. This indicates that the phosphoric rock formed at the early transgression cyclic deposition during the global warming period. Phosphorite sedimentary rock is characterized by well-developed lentieular tidal bedding, and ripple mark and desiccation crack are very common. Ore minerals occur as spherical oolite texture, showing the feature of colloform deposition. Ore minerals are predominantly comprised of amorphous collophanite. Ore composition and lithochemieal analysis show that the ore consists mainly of fluor-apatite and earbonatic minerals such as high-Mg dolomite and silicatic detrial minerals. P-bearing rock series is characterized by high content of rare earth elements and uranium, distinct negative Ce anomalies in REE distribution diagram of phosphorite ores, and positive relation between REE enrichment and Fe203 , strongly suggesting an environment of shallow oxidation deposition. All these features indicate that P-bearing sedimentary formation formed mainly in a littoral area containing supratidal, intertidal and subtidal shallow zones. Therefore, the deposit formed mainly in a sedimentary environment of either stable platform margin or a shallow continental shelf关键词
昆阳磷矿/沉积环境/矿床地球化学Key words
Kunyang phesphorite deposit/ sedimentary environment/ deposit geochemistry分类
天文与地球科学引用本文复制引用
杨帆,肖荣阁,夏学惠..昆阳磷矿沉积环境与矿床地球化学[J].地质与勘探,2011,47(2):294-303,10.基金项目
中化地质矿山局资助项目(编号:2009-地-13),名称:中国磷矿床研究. （编号:2009-地-13）
