西昆仑甜水海地块大红柳滩铁矿床成因浅析及找矿意义

位于西昆仑甜水海地块东段的大红柳滩赤铁矿是近几年发现的大型铁矿床,产于震旦纪甜水海岩群滨浅海相浅变质碎屑岩-碳酸盐岩中,赋矿岩性主要为含铁白云质大理岩、白云母石英片岩和硬绿泥石白云母石英片岩。通过矿体形态特征、矿物组合和矿石结构构造分析,认为该时期存在缺氧富铁洋盆或者深水盆地,矿床的形成经历了铁质沉积和变质改造两个阶段,属于新元古代沉积变质成因条带状硅铁建造矿床(BIF),找矿潜力巨大。该矿床是继塔什库尔干县一带发现了多个与火山岩建造密切相关的大型规模Algoma型BIF之后的重大找矿突破,也是西昆仑地区首次发现该类型矿床。深入开展该矿床的地质特征及勘探工作,能够指导西昆仑铁矿的下一步找矿方向,推进新疆地区条带状含铁建造(BIF)研究和西昆仑构造格局演化的认识。

Genesis of the Dahongliutan Iron Deposit in the Tianshuihai Terrane,West Kunlun and its Prospecting Significance

The newly discovered large Dahongliutan hematite-rich iron deposit is located in the eastern part of the Tianshuihai terrane, West Kunlun. This deposit is mainly hosted in a suite of Sinian greenschist facies-metamorphosed shallow marine siliciclastic-carbonate rocks of the Tianshuihai Group. Ore bodies are mainly interlayered with ferroan dolomitic marble, chloritoid muscovite-quartz schist and muscovite-quartz schist. The morphology of ore bodies, texture and structure of the ores and mineral assemblage show that the formation of iron ore underwent sedimentary diagenesis, metamorphism and late stage alteration. The deposit is of BIF-related sedimentary metamorphic type iron deposit related to anoxic and ferruginous basins. The iron deposit shows excellent exploration potential and is a new type of deposit in the West Kunlun orogenic belt, and indeed some large-scale Algoma-type BIFs associated with volcanic rock assemblage were discovered in the Paleoproterozoic Bulunkuole Group, Taxkorgan County. Deep research on the geological characters of the ore deposit will surely contribute to the iron deposit exploration in the Western Kunlun Range and advance our understanding on BIFs in Xinjiang and tectonic evolution of the West Kunlun orogenic belt.