西秦岭文县沟岭子沉积改造型锰矿矿床地质特征及成因研究

Geological Characteristics and Genesis of Goulingzi Sedimentation-Reworked Manganese Deposit in Wenxian County,Western Qinling Mountains

研究区位于摩天岭古陆北缘裂谷盆地,关家沟背斜东南翼,特殊的地质构造环境,形成了龙门山-大巴山(台缘坳陷)Fe-Cu-Pb-Zn-Mn-V-P-S-重晶石-铝土矿成矿带。矿床主要富集于关家沟古陆两侧的滨海台地稳定的碳酸盐建造中,岩石地球化学分析表明,矿床形成环境为古陆缘浅海陆棚和滨海台地区。通过地质特征综合分析,认为沟岭子沉积改造型锰矿经历了震旦纪原始沉积期—印支变质改造期—喜山次生改造期3个时期,在关家沟古陆与摩天岭古陆间受隔阻的近滨海台地环境中形成。

This area is located in the rift basin of the northern margin of Motianling paleocontinent acrossing the southeast wing of the Guanjiagou anticline.The special geological tectonic environment formed the Fe-Cu-Pb-Zn-Mn-V-P-S-barite-bauxite metallogenic belt of the Longmenshan-Dabashan(Taiyuan depression).The deposit is mainly concentrated in the stable carbonate formation of the coastal platform on both sides of the guanjiagou ancient land.Our petrogeochemistry analysis shows that the deposit is formed in the shallow sea shelf and coastal platform area of the paleocontinental margin.In the comprehensive analysis of geological characteristics,it is considered that Goulingzi sedimentary remoulded manganese ore were formed in the near coastal platform environment between guanjiagou ancient land and Motianling ancient land,experiencing three periods of sinian primary sedimentary period-Indosinian metamorphic remoulded period-Himalayan secondary remoulded period.