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

Chilas、Jijal 和 Kohistan 增生岛弧地体基底超镁铁质-镁铁质堆积杂岩的岩石学和成矿潜力

• 批准号: 8817353
• 负责人: Donald Levandowski
• 金额: $ 12.24万
• 依托单位: Purdue Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-02-15 至 1991-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8817353&HistoricalAwards=false
• 关键词: Petrology; Mineralization; Potential; Chilas; Jijal

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.

科希斯坦的异国情调的N。巴基斯坦被并入亚洲 中白垩世，平面上呈“侧倾”出露 一个基本上完整的垂直剖面穿过地壳， 洋内岛弧复合体的上地幔。 下方 火山岩和钙碱性岩基序列是一个巨大的低 地壳镁铁质-超镁铁质-层状堆晶杂岩， 记录了分化过程，通过这些过程，“初级” 来自地幔的玄武岩熔体在下地壳演化， 产生高铝玄武岩和玄武安山岩， 控制着喷发序列 深成层状堆积 提供了重要的岩石成因证据， 钙碱性岩浆系列，这与推断的证据完全不同 来自于对熔岩斑晶组合的研究。 累积 是世界上最大的层状镁铁质岩群之一 超镁铁质岩，可能是矿物的主要储藏库 财富 通过综合实地研究和全岩， 矿物地球化学研究在一系列横贯 累积系列，这项合作研究涉及地球科学家 来自阿扎德查谟和克什米尔大学和普渡大学， 有望澄清重要的岩石成因问题， 对堆积层序地层段进行筛选， 有希望作为铂、镍、铜、铬和 钒矿床，采用创新的成矿成岩 概念和岩石地球化学勘探技术。