张朝举 苏威 郭江波 余敏华

摘要：本文通过对瓮福磷矿穿岩洞矿段磷矿层的矿物成分、化学成分、结构构造、岩相古地理与磷成矿作用关系的综合研究，认为生物化学成磷作用和机械簸选富集作用是研究区主要磷成矿作用，并经历了初次富集、改造富集及次生富集三个阶段，建立了瓮福磷矿穿岩洞矿段磷成矿模式。认为容磷海水在上翻洋流的驱动下，由东向西漫上整个碳酸盐台地，经过藻类生物的浓缩，吸取，转移聚沉积海底，达到磷质初次富集。其后，早浅水以波浪作用为主簸选下，导致了磷质颗粒化及物理机械富集，最后在有利的沉积场所浅滩，形成了工业磷块岩矿床。

关键词：地质特征；磷成矿作用；成矿模式；穿岩洞磷矿床

Abstract：Based on comprehensive research of mineral component， chemical component， texture and structure， the relationship between lithofacies paleography and phosphoric mineralization of phosphatic bed of Chuanyandong phosphorus deposit， this paper considers that phosphoric mineralization of study region is mainly consistuted by biochemical phosphorus mineralisation and Mechanical winnowing enrichment， and experienced three steps of Primary enrichment， transformation enrichment， secondary enrichment.And the metallogenic model has been established for phosphate deposits of this area.This study suggests that phosphoric mineralization is formed by the paleographic spaciel shallow environment of continental margin bay.Rich phosphorus seawater group which moved from deep sea into limited space sedimentary basin and could not easily spread， experienced evaporation， concentration for long time and phosphoric supersaturation， formed selfgenerating phosphate rock highly enriched in phosphorous by the participation of large primitive algae liking phosphorous and suitable chemical conditions.

Key words：Geological characteristic；phosphoric mineralization；Metallogenic model；Chuanyandong phosphorus deposit

穿巖洞矿段是瓮安福泉地区典型磷矿床之一，开展该矿床的地质研究工作，对指导该区磷矿找矿工作具有重要的指示意义。该矿床成磷作用主要发生于早震旦世陡山沱期。由于 Rodinia 大陆的裂解作用的进行，自晚元古代早震旦世开始，形成大洋中脊伴随火山喷发作用，深部物质的带出，气候转暖，形成富氧条件，海洋循环活动频繁，为该区域陡山沱期成磷作用提供了环境条件和物质条件，形成由磷质岩、含磷硅质岩、含磷白云岩、磷质岩、铁磷岩组成的台棚相（亚相为磷质台棚浅滩相）建造。

本文通过对瓮安福泉地区典型磷矿床瓮福磷矿穿岩洞矿段的地质特征、岩相古地理进行综合研究，讨论该区磷成矿作用，并建立磷矿成矿模式，为该区磷矿找矿勘查提供可能的思路。……