Petrology and Mineralization Potential of the Chilas, Jijal,and Related Segements of the Basal Ultramafic-Mafic CumulateComplex, Kohistan Accreted Island Arc Terrane

巴基斯坦北部的Kohistan奇异地体在白垩纪中期被增生到亚洲，并“边缘上升”，在平面上显示出一个基本完整的垂直剖面，穿过海洋内岛弧复合体的地壳和上地幔。在火山和钙碱性岩基层序下面是一个巨大的下地壳基性-超基性-层状堆积复合体，它提供了一个分化过程的记录，通过这个过程，“初级”玄武岩从地幔中融化，在下地壳中进化，产生了主导喷发序列的高铝玄武岩和玄武岩安山岩。深成岩层状堆积为钙碱性岩浆系列的岩石成因提供了重要的证据，这与从熔岩斑晶组合研究中推断出的证据截然不同。这一堆积杂岩是世界上最大的层状基性-超基性岩石之一，可能是矿产财富的主要宝库。通过综合野外研究和全岩和矿物地球化学研究，在一系列穿越堆积系列的穿越中，来自阿扎德查谟和克什米尔大学和普渡大学的地球科学家参与了这项合作研究，预计将澄清重要的岩石学问题，并筛选最有希望成为铂、镍、铜、铬和钒矿床的地层间隔的累积序列。采用创新的成矿概念和岩石地球化学勘探技术。

The Kohistan exotic terrane of N. Pakistan was accreted to Asia in the Mid-Cretaceous and turned "edge-up" to expose in plan view an essentially complete vertical section through the crust and upper mantle of an intra-oceanic island arc complex. Beneath the volcanic and calc-alkaline batholith sequence is an immense lower crustal mafic-ultramafic-layered cumulate complex that provides a record of the differentiation processes by which "primary" basaltics melts from the mantle evolved in the lower crust to yield the high-alumina basalts and basaltic andesites that dominate the eruptive sequence. The plutonic layered cumulates provide important evidence regarding the petrogenesis of the calc-alkaline magma series that is quite unlike evidence deduced from the study of phenocryst assemblages in lavas. The cumulate complex is one of the world's largest exposures of layered mafic- ultramafic rocks and is potentially a major storehouse of mineral wealth. By means of integrated field studies and whole-rock and mineral geochemical studies in a series of traverses across the cumulate series, this cooperative study involving geoscientists from Azad Jammu and Kashmir University and Purdue University is expected to clarify important petrogenetic questions and to screen the cumulate sequence for stratigraphic intervals most promising as hosts to platinum, nickel, copper, chromium, and vanadium ore deposits, employing innovative ore-petrogenetic concepts and lithogeochemical exploration techniques.