四川省什邡式磷矿地质特征及其成矿模式

Geological characteristics and metallogenic mode of Shifang-type phosphate mine in Sichuan province

四川省什邡式磷矿是四川省重要的中高品位磷矿资源,产于上泥盆统沙窝子组含磷段底部。层位稳定,呈层状-似层状产出,磷块岩常与硫磷铝锶矿或含磷粘土岩渐变过渡。厚度受底板古岩溶侵蚀面起伏控制,变化较大。矿床分布方向与区域构造线方向一致。通过研究区成矿地质背景、代表性矿床、各个矿床地质特征分析,探讨什邡式磷矿区域成矿模式,什邡式磷矿成矿过程经历了早期成矿阶段、大陆成矿作用和海进沉积再造成矿三个阶段,具有多期成矿、叠加成矿特征。

Shifang phosphate mine is an important medium and high-grade phosphate mine resource in Sichuan Province,which exists at the bottom of the Upper Devonian Shawozi Formation with the stable layers and layer-like occurrence,phosphorite often transition gradually to svanbergite or phosphate-bearing clay rock.The thickness is controlled by the underlying plate ancient karst erosion surface fluctuation,and it changes greatly.The deposit distribution direction is consistent with the regional structural line direction.Through the analysis of geological background,typical deposit and each deposit in the study area,the metallogenic model of Shifang phosphate mine were discussed.Shifang phosphate metallogenic process experiences three stages of Early mineralization stage,continental mineralization and re-sedimentation stage in marine transgression,.and is of characteristics of multiple stage and superposition mineralization.