【摘要】 对冈底斯岩带中部,谢通门唐河电站花岗闪长岩中锆石进行SHRIMP U-Pb定年,结果为45.1±1.7Ma(始新世),岩体的形成时代相当于印度和欧亚两个大陆碰撞的峰期时间,说明谢通门花岗闪长岩为同碰撞花岗岩。更多还原

【Abstract】 The Xietongmen pluton is located between Xietongmen County and Rikaze City, which belongs to middle part of the Gangdise belt in southern Tibet. The pluton invades in the Carboniferous and Cretaceous in the north; and is covered by the Quaternary sandstones in the south. The pluton is composed mostly of granodiorites and porphyritic biotite granites. Chemically,the granodiorite is peraluminous series.SHRIMP zircon U-Pb dating technique is applied to the granodiorites of the Xietongmen pluton. The result shows that the formation time of the Xietongmen pluton is 45.1±1.7Ma. Most geologists think the Indian-Asian collision began 50Ma ago, so the Xietongmen pluton is syn-collision granodiorite. This result provides a significant evidence for accurately ascertaining the time of the Indian-Asian continental collision.更多还原