【摘要】 新疆尉犁县且干布拉克超基性杂岩体位于塔里木北缘隆起带库鲁克塔格前寒武纪地块中西段,兴地塔格断裂带附近。该蛭石矿床是继南非Palabora、美国Libby和俄罗斯Kovdorsk蛭石矿之后的第4个超大型蛭石矿床。根据野外地质观察和室内薄片鉴定结果,结合该区已有的岩石地球化学和矿床学资料,并通过与国外同类型矿床进行详细对比,从含矿杂岩体的岩石组合、矿体发育特征和矿物共生组合等不同层面探讨了该杂岩体的演化过程和矿床成因,并建立了相关成岩成矿模型。结果表明,且干布拉克杂岩体是裂谷背景下,富集岩石圈地幔低程度部分熔融岩浆经岩浆分异和不混熔作用并以橄榄岩-黑云母透辉岩-碳酸岩等岩相依次侵入的产物,蛭石矿床中的金云母是岩浆晚期高温富碱质热液交代超基性岩的产物,云母类矿物在剥蚀到近地表后,在大气降水作用下发生表生风化最终形成蛭石矿床。矿床的形成过程复杂,经历了从地幔交代、超大陆裂解、岩浆分异、热液蚀变到表生风化作用等五大地质过程。这一模式的建立将为进一步寻找和深入研究该类矿床提供理论依据和实践指导。更多还原

【Abstract】 The Qieganbulak vermiculite ore deposit lies in Yuli Country of Xinjiang.The ore-bearing pluton is an alkaline ultramafic-carbonitite complex located along the Xindi fault in western Quruqtagh block,a Precambrian uplift unit of North Tarim craton.The deposit is the fourth superlarge vermiculite deposit discovered in the world after Palabora of South Africa,Libby of the USA and Kovdorsk of Russia.Based on field geological survey,thin section identification and previous petrological,geochemical and ore mineral data,the authors compared the Qieganbulak deposit with other three superlarge vermiculite ore deposits in the word and discussed the genesis and ore-forming evolution in the aspects of petrographic association,ore body characteristics and mineral paragenesis,and established the formation mechanism model for its petrogenesis and metallogeny.Five major geological processes,i.e.,mantle metamorphism,supercontinental breakup,mantle-derived magma differentiation,hydrothermal alteration and supergene weathering,have been proposed for the formation of the Qieganbulak superlarge vermiculite ore deposit.更多还原