CAJ | 학술논문

巴仑台闪长岩反映的大洋俯冲信息为对比乌瓦门蛇绿岩与西侧长阿吾子和东侧库米什蛇绿岩的关系，探讨南天山洋的洋-陆演化过程具有重要意义。闪长岩具高碱和高铝特征，（Na2O+K2O）=4.14%~7.05%，Al2O3为14.62%~17.35%，为一套高钾钙碱性系列岩石，(La/Yb)N平均10.46，以富集轻稀土元素和大离子亲石元素（如K、Rb、Ba、Pb等）、亏损Nb、Ta、Ti等高场强元素为特征，形成于岛弧环境。闪长岩LA-ICP-MS锆石U-Pb年龄为（430.1±1.1） Ma，锆石εHf（t）=-12.7~-7.6，二阶段Hf模式年龄TDM2为1895~2219 Ma，指示巴仑台闪长岩为早志留世南天山洋北向俯冲，导致中天山古老结晶基底部分熔融形成。
파륜태섬장암반영적대양부충신식위대비오와문사록암여서측장아오자화동측고미십사록암적관계，탐토남천산양적양-륙연화과정구유중요의의。섬장암구고감화고려특정，（Na2O+K2O）=4.14%~7.05%，Al2O3위14.62%~17.35%，위일투고갑개감성계렬암석，(La/Yb)N평균10.46，이부집경희토원소화대리자친석원소（여K、Rb、Ba、Pb등）、우손Nb、Ta、Ti등고장강원소위특정，형성우도호배경。섬장암LA-ICP-MS고석U-Pb년령위（430.1±1.1） Ma，고석εHf（t）=-12.7~-7.6，이계단Hf모식년령TDM2위1895~2219 Ma，지시파륜태섬장암위조지류세남천산양북향부충，도치중천산고로결정기저부분용융형성。
Studies of petrology and geochemistry indicate that the Baluntai diorite is the high-K calc-alkaline diorite. The rocks, which have the data Na2O+K2O=4.14%-7.05%, Al2O3=14.62%-17.35%, (La/Yb)N with an average of 10.46, are characterized by enrichment of large ion lithophile elements (LILE, such as K, Rb, Ba, and Pb) and light REE but depletion of high field strong elements (HFSE, like Nb, Ta, and Ti),and were probably produced in an island arc settings. LA-ICP-MS zircon U-Pb dating shows that the Baluntai diorite was formed at (430.1 ± 1.1)Ma. In-situ zircon Hf analyses show that zircons from Baluntai diorite have εHf(t) values from -12.7 to –7.6 and tDM2 model ages of 1895 Ma to 2219 Ma. Combined with Hf isotope analytical results and regional geological data, it is held that the Baluntai diorite resulted from partial melting of the Tianshan crystalline basement in response to northward subduction of South Tianshan Ocean during the Early Silurian. The isotopic ages of the Baluntai diorite body represent the upper age limit of theWuwamen ophiolite.