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借助阴极发光显微照相(CL)及激光剥蚀电感耦合等离子质谱技术(LA-ICPMS),观察和分析了东天山咸水泉片麻状花岗岩锆石晶体的内部结构及稀土元素和U,Th含量.该岩体中的锆石由具有振荡环带及强烈阴极发光的部分和无振荡环带及阴极发光(表现为暗黑色)的部分组成.具有振荡环带及强烈阴极发光的部分多为锆石核部,而无振荡环带及阴极发光(表现为暗黑色)的部分多为锆石边部.热液锆石富集稀土元素,其球粒陨石稀土配分曲线位于岩浆锆石之上,热液锆石LREE球粒陨石标准化值较岩浆锆石高2—3个数量级,其标准化曲线仅表现为轻微倾斜,并具较小的Ce正异常(Ce/Ce*为1.5-2.4,岩浆锆石Ce/Ce*为2.0-20.7)及适度Eu负异常(Eu/Eu*为0.28-0.32,岩浆锆石Eu/Eu*为0.29-0.41).热液锆石Th,U含量和Th/U值均比岩浆锆石高出数倍.研究认为,片麻状花岗岩是由经过韧性剪切和糜棱岩化的泥盆纪花岗闪长岩在二叠纪受到深源流体—熔体强烈改造的产物.核部锆石为继承下来的原岩锆石,而增生的热液锆石边则形成于深源流体—熔体将原岩改造成片麻状花岗岩的过程中.
The internal structure, contents of rare earth elements and U, Th in the zircon crystals of the Xianshuiquan gneissic granite in the East Tianshan Mountains were observed and analyzed by using cathodoluminescence micrograph (CL) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). The zircon in this rock mass consists of a part with oscillatory ring and intense cathodoluminescence and a part with no oscillatory ring and cathodoluminescence (appearing as dark black) .The part with oscillatory ring and strong cathodoluminescence is mostly zircon While the non-oscillatory zone and cathodoluminescence (dark-colored) are mostly marginal zircons.The hydrothermal zircon enriches the REE, and the chondrite melatonite distribution curve is located on the magmatic zircon, The normalized value of liquid LREE chondrites is 2-3 orders of magnitude higher than that of magmatic zircons, and the normalized curve shows only a slight tilt with a small positive Ce anomaly (Ce / Ce * of 1.5-2.4, magmatic zircon Ce / Ce * is 2.0-20.7) and moderate Eu negative anomalies (Eu / Eu * is 0.28-0.32, magmatic zircon Eu / Eu * is 0.29-0.41) .Thermal zircon Th, U content and Th / U value Are several times higher than the magmatic zircon.Studies believe that the gneissic granite is ductile shearing and mylonitization of the Devonian granite flash Feldspar is strongly altered by deep-source fluid-melt in the Permian. The zircon from the core is a succession of protoliths, whereas the accretionary hydrothermal zircon is formed in the deep-source fluid-melt Rock into the gneissic granite process.