东准噶尔地区与韧-脆性剪切带有关的金(铜)成矿——构造变形转换与成矿时限及地球动力学背景

Au(Cu) mineralization associated with ductile-brittle shear zone in east Junggar area: conversion of structural deformation,metallogenic time and geodynamics background

东准噶尔地区位于哈萨克斯坦—准噶尔板块与西伯利亚板块缝合带南侧,是新疆北部主要的金多金属成矿带。与韧-脆性剪切带有关的金矿床是该地区最重要的金矿床类型,研究表明,韧-脆性剪切变形构造也是部分铜成矿作用的主要控矿因素。成矿同位素年代学和地球动力学研究表明,东准噶尔地区与韧-脆性剪切带有关的金(铜)成矿作用集中于晚石炭世—早二叠世(260～305 Ma),其次为中三叠世(230 Ma±),相应的构造背景是华力西晚期陆内后碰撞伸展构造环境及印支早期板内稳定体制下的造山带抬升伴随的逆冲剪切构造活化热事件。

East Junggear area locates in southern suture zone of Kazakhstan-Junggear plate and Siberia plate,which is the main Au-polymetallic metallogenic belt in northern Xinjiang.Gold deposit associated with ductile-brittle shear zone is the most important deposit type in the area.The study showed that ductile-brittle shear deformation structure was also the main ore-controlling factor in some copper mineralization.Studies on metallogenic isotopic geochronology and geodynamics revealed that Au（Cu） mineralization associated with ductile-brittle shear zone in the area appeared in late Carboniferous-early Permian（260-305 Ma）,secondly appeared in middle Triassic（230 Ma±）.The corresponding structural backgrounds were inner continental post collision-extension structure environment of late Variscan and thermal events of thrusting-shearing tectonic activation under stable inner plates system in early Indo-Chinese epoch,which were aroused by orogenic belts uplifting.