西北地质2024，Vol.57Issue(2)：1-13,13.DOI:10.12401/j.nwg.2023032
扬子北缘新元古代基性岩体铂族元素特征及找矿意义
Characteristics of Platinum Group Element in Neoproterozoic Mafic Intrusions in the Northern Margin of the Yangtze and Exploration Implications
摘要
Abstract
Multiple layered mafic intrusions occur along the northern margin of the Yangtze Block,SW China.The Neoproterozoic Bijigou and Wangjiangshan mafic intrusions are two of the best exposed intrusions in the region.The Bijigou and Wangjiangshan mafic intrusions are thought to be generated by 10%to 20%of partial melting of a depleted mantle source.Uniformly high Cu/Pd(3.52×104～3.97×105 for the Bijigou samples and 1.78×104～1.61×106 for the Wangjiangshan samples)indicate that the parental magma of these intrusions experi-enced prior sulfide segregation before their intrusions into the shallow crust.Positive correlation between IPGE with whole-rock Ni,and negative correlation between Cu/Ir and Ni/Pd illustrate that the distribution of PGE is mainly controlled by the accumulation of olivine under an S-unsaturated condition.In comparison no linearly correlation between PGE and whole-rock Ni,V and TiO2,and positive correlation between Cu/Ir and Ni/Pd il-lustrate that the PGE in the Wangjiangshan intrusion is controlled by the second-stage sulfide saturation.The general lack of parallel alignment of tabular minerals in the Bijigou and Wangjiangshan intrusions,combined the PGE depletions in the Wangjiangshan second segregated sulfides,indicates that these intrusions probably intrud-ed and cooled under a single episode of magma replenishment,rather than a dynamic magma conduit system.Therefore the shallow part may not have the conditions to host large deposits and future prospecting work should focus on the deeper part.关键词
新元古代/基性岩体/铂族元素/硫化物熔离/扬子板块Key words
Neoproterozoic/mafic intrusion/PGE/sulfide segregation/Yangtze block分类
天文与地球科学引用本文复制引用
李章志贤,郑绍鑫,张晓琪..扬子北缘新元古代基性岩体铂族元素特征及找矿意义[J].西北地质,2024,57(2):1-13,13.基金项目
国家自然科学基金项目"中国西部典型岩浆铂族元素和钴金属超常富集成矿动力学"(91962212),"扬子北缘新元古代早期低氧同位素锆石成因:幔源岩石多元同位素示踪"(42173005),陕西省教育厅项目"北秦岭松树沟铬铁矿矿床成矿机制研究"(15JK1760),西北大学地质学系国家基础科学人才培养基金"矿物成分对幔源岩浆氧化还原状态的制约"(XDCX2020-15)联合资助. （91962212）
