陕西勉县后沟-大坪山矿区磷、锰分层成矿地质地球化学特征
Geological and Geochemical Characteristics of P and Mn Layering Mineralization of Hougou-Dapingshan Area in Mianxian, Shaanxi Province
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摘要: 后沟-大坪山矿区位于南秦岭磷、锰成矿带的中东段,近年来在下寒武统塔南坡组中发现了3条含磷、锰矿化带,并圈定出多个锰矿体和磷矿体.磷、锰矿体具有多层性,常表现为磷、锰的分层成矿,多呈上锰下磷的空间分布特征.通过分析Ⅱ矿化带内地表和深部样品的常量元素、微量元素和稀土元素的地球化学特征,发现磷、锰矿其物质来源具有一定的相似性,但是磷、锰矿石沉积的氧化-还原条件、沉积区域以及沉积水体条件都存在差别,这可能是引起磷、锰分离单独成矿的主要原因.Abstract: Hougou-Dapingshan area,where three manganese(Mn)-phosphor(P) metallogenic belts were discovered recently in Lower Cambrain Tananpo Formation,located in the middle-eastern segment of the South Qinling Mn-P Metallogenic Zone.There were four Mn orebodies and one P orebody in the Ⅱ metallogenic belts.It is often that Mn-P orebodies were separated with a texture of upper Mn seam and lower P seam.The geochemical characteristics of the surface and deep rocks samples of major trace elements from the Ⅱ metallogenic belts were analyzed.The results show that the material source of Mn-Porebodies is similar,but both sediment ary environment including the sediment ary redox conditions,sediment ary area and water body condition is different.These are possible major reasons for Pand Mn separate layering mineralization.