贵州福泉地区晚陡山沱期磷矿成因及古地理控矿意义

福泉磨坊和英坪磷矿是陡山沱期磷矿的典型矿床之一,其中陡山沱期磷矿的上矿层(b矿层)开采条件较好、含磷资源量较大及品位较高的海相含碘磷块岩矿床为典型的特征。主要类型为砂屑磷块岩、含磷质或白云质团块状磷块岩和致密块状磷块岩,矿层下部发育有条带状构造,P2O5品位较高,并矿层下部向上逐渐增高。研究区晚陡山沱期与磷矿有关的沉积环境为聚磷浅滩相,它是经历了一次陆地抬升之后又下降接受沉积发展而来的。在该层底部存在一侵蚀面,它对磷块岩的沉积厚度具有一定的影响。

Genetic facts of the phosphorite ore in late Doushantuo Formation and significance of paleogeographic control to the ore in the area of Fuquan,Guizhou

Fuquanmofang and Yingping phosphate deposits are typical in Doushantuo phosphorite deposits The upper mine (b ore deposit) of phosphorite deposit in Doushantuo age is characterized by better mining condition, iodine-containing marine phosphate rock deposit of larger amount and higher grade. The main types of rocks include psammitic phosphate rock, phosphorus-containing or dolomitic nodular-containing phosphorus rock and compact massive phosphorus rock. There is banded structure developed in the lower strata. P₂O₅ grade is relatively high, and gradually increased from the lower strata to the higher strata. The Late Doushantuo sedimentary environment is polyphosphate shoal, which experiences a decline after the land uplift has evolved, to accept deposits. There is an erosion surface at the bottom of the layer which influences to some extent deposit thickness of the phosphate rock.