【摘要】 东天山尾亚钒钛磁铁矿矿床是北疆地区最大的钒钛磁铁矿矿床,其含矿岩系为一套偏碱性的镁铁-超镁铁质杂岩。含矿岩石主要造岩矿物橄榄石、辉石、角闪石、黑云母和斜长石的化学成分与铁质系列的镁铁-超镁铁岩成分相似或相同;辉石、角闪石、黑云母等矿物以富钛为特点,这些矿物中Ti、Fe等在早期形成的岩石（辉橄岩、橄榄辉长岩）中较晚期岩石中有明显富集。含矿辉长岩的锆石LA-ICPMS U-Pb同位素定年结果为236±3Ma,主要成岩时代为中三叠世,代表后碰撞结束阶段的成矿作用。这套含矿镁铁-超镁铁杂岩的Sr-Nd同位素特征以ε_Nd（t）均为正值,(⁸⁷Sr/⁸⁶Sr)_i值较低为特征,与原始地幔相近,但在岩浆上移过程中可能有陆壳物质加入。更多还原

【Abstract】 Weiya V-Ti-magnetite deposit in Eastern Tianshan is the biggest one in North Xinjiang which the host rock belongs to a set of partial to alkalic mafic-ultramafic complex.Composition of main rock-forming minerals such as olivine,pyroxene,amphibole, biotite and plagioclase is in accord with that of ferruginous mafic-ultramafic rocks.Pyroxene,amphibole and biotite distinctly are Ti-rich,and the Ti and Fe contents commonly enrich in early stage rocks（e.g.pyrolite and olivine gabbro）.LA-ICPMS isotopic dating of zircon from gabbro is 236±3Ma which means the diagenetic age of Middle Triassic and represents an end stage of postcollisional mineralization.The Sr-Nd isotope of the host mafic-ultramafic complex is characterized by identically positiveε_Nd（t）value and lower(⁸⁷Sr/⁸⁶Sr)_i value,which suggests that the magma might be derived from mantle but mixing into continental crust material during magma moving up.更多还原