黔中陡山沱期磷块岩成矿机制

本文运用多学科的理论和方法,研究了黔中陡山沱期磷块岩的岩石学、矿物学特征、富磷环境、成磷机制等。提出了磷块岩的“结构-成分-成因”综合分类方案,阐述了磷酸盐矿物中CO_2的存在形式和演变趋势;指出了浅水台地边缘高能带是磷酸盐富集的有利场所;论证了海底大山供磷、生物沉磷和多因素富磷的成矿过程;最后探讨了区域地质演化对磷块岩成矿的控制。

SEDIMENTARY GEOLOGY AND PHOSPHORUS-FORMING MECHANISM OF PHOSPHORITE IN DOUSHANTUO STAGE IN CENTRAL GUIZHOU

The central Guizhou Doushantuo phosphorite has been systematically studied with respect to its lithology,mineralogy, environment and mechanism of phosphate enrichment. A new principle of classification, namelythe "texture-composition-genesis"combined classification has been proposed. The role of CO_2, its occurencesand evolution trend in phosphate minerals have been investigated in detail. The author concludes that theshallow water platform margin zone is the most favourable place for phosphate enrichment. The ore-form-ing process consists of at least three steps: (1) sea floor volcanism providing with phosphorus source, (2)organism helping its accumulation, (3) a series of other factors favouring phosphorus enrichment. Re-gional geological controlon the phosphorite formation is also discussed.