摘要
新疆东准噶尔卡拉麦里地区是一个重要的锡成矿带,分布有多种类型的花岗岩。贝勒库都克岩体位于卡拉麦里锡成矿带中部,由含锡正长花岗岩和黑云母二长花岗岩组成。本文对贝勒库都克岩体岩相学和含锡黑云母正长花岗岩的锆石LA-ICPMSU-Pb定年研究,结果表明所有锆石颗粒浅黄色-无色透明,呈正方双锥状、钮柱状及半截锥状自形晶体,且发育规则的韵律环带,具有较高的Th/U比值(范围在0.32～0.47),属于典型岩浆成因锆石。获得贝勒库都克岩体侵位结晶年龄为283±2Ma(n=8,MSWD=0.14),时代属于早二叠世,这与东准噶尔后碰撞深成岩浆活动的范围(330～265Ma)相吻合。为建立准噶尔地区构造格架和恢复岩浆演化事件提供了最有力的证据,同时具有一定的找矿意义。
Several types of granites are distributed in the Kalamaili area of East Junggar,Xinjiang,which constitutes an important tin metallogenic zone.The Belekuduke granitiod is situated in the centre of the tin metallogenic zone,which consists of biotite syenite granites and biotite monzogranites.On the basis of the preliminary petrological study,the ore-hosting biotite syenite granite of the Belekuduke intrusion is dated by the zircon LA-ICPMS U-Pb method.The zircon grains are of typical magmatic origin,characterized by light yellow-colorless transparent,a square bipyramid,button cylindrical and half cone-shaped crystals,and regular metric zone.The zircon LA-ICPMS U-Pb dating with 283±2Ma （n=8,MSWD=0.14,Th/U ratios of 0.32～0.47） represents the emplacement age of the ore-hosting biotite syenite granite,the time belongs to the Early Permian,which coincides with the period of 330～265Ma,an indicative of the hypogene magma moving of post-collision in East Junggar.The LA-ICPMS U-Pb zircon age from the ore-hosting biotite syenite granite takes an evidence for rebuilding tectonic framework and recovering magma evolution,and has the implication for finding tin deposits in the Kalamaili area of East Junggar,Xinjiang.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2010年第1期133-138,共6页
Geotectonica et Metallogenia
基金
国家自然科学基金项目(40534020)
区域地质矿产调查项目(QD200508)
