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祁连南缘嗷唠山花岗岩锆石的SHRIMP年龄变化于445~496Ma之间,平均为 473 Ma,属早奥陶世。年龄值的统计出现两个峰值,第一个峰值与区内榴辉岩的相同(495 Ma),可能反映花岗岩源岩的部分熔融时代,第二个年龄峰值可能反映了花岗质岩浆的冷凝结晶时代(465 Ma)。该花岗岩的岩石地球化学特征类似于Ⅰ型花岗岩,有关构造环境判别图解得出,该花岗岩类似于岛弧或活动陆缘环境。结合区域地质特征和花岗岩的锆石SHRIMP年龄特征,我们认为,早奥
The SHRIMP ages of the Qiangtang granites in the southern margin of Qilian range from 445 to 496 Ma with an average of 473 Ma, belonging to the Early Ordovician. There are two peaks in the statistics of the age value. The first peak value is the same as that of the eclogite in the area (495 Ma), which may reflect the partial melting time of granite source rocks. The second peak of age may reflect the condensation of granite magma Crystallization Age (465 Ma). The geochemistry of the granite is similar to that of the type I granite, which is derived from the discrimination of the tectonic environment similar to the island arc or the active continental margin. Combined with regional geological features and granite zircon SHRIMP age characteristics, we believe that as early Austrian