CAJ | 학술논문

中天山地块发育有大量的暗色岩墙，主要走向为北北西。对中天山暗色岩墙进行LA-ICP-MS锆石U-Pb测年，获得的年龄为304.8±1.5Ma，表明其形成于晚石炭世。这些暗色岩墙具有较高的SiO2，较低的Mg、Cr、Ni含量。它们富集大离子亲石元素（Rb、Ba、Th），亏损高场强元素（Nb、Ta、Ti），显示俯冲相关特征。上述特征暗示，中天山暗色岩墙可能是由俯冲板片流体交代的地幔楔部分熔融形成的。这一发现表明，准噶尔洋的闭合应该发生在晚石炭世之后。
중천산지괴발육유대량적암색암장，주요주향위북북서。대중천산암색암장진행LA-ICP-MS고석U-Pb측년，획득적년령위304.8±1.5Ma，표명기형성우만석탄세。저사암색암장구유교고적SiO2，교저적Mg、Cr、Ni함량。타문부집대리자친석원소（Rb、Ba、Th），우손고장강원소（Nb、Ta、Ti），현시부충상관특정。상술특정암시，중천산암색암장가능시유부충판편류체교대적지만설부분용융형성적。저일발현표명，준갈이양적폐합응해발생재만석탄세지후。
The NNW-trending dark dykes widely occur in Central Tianshan Mountains. The LA-ICP-MS zircon U-Pb dating of dark dyke yielded a weighted mean 206Pb/238U age of 304.8 ± 1.5Ma, suggesting that they were generated in Late Carboniferous. The dark dykes are characterized by low Mg, Cr and Ni values. These samples are enriched in LILEs (e.g., Rb ,Ba,Th) and depleted in HFSEs (e.g., Nb, Ta, Ti). The dark dykes were likely generated by interaction of mantle wedge with fluids derived from dehydration of the subducting slab. The closure of the Junggar Ocean probably terminated after Late Carboniferous.