东昆仑隆升作用的裂变径迹研究

Apatite Fission Track Evidence on the Uplifting of Eastern Kunlun Mountains

对东昆仑山东段都兰 布青山近南北向剖面采集样品进行了磷灰石裂变径迹分析。所获得的 41件磷灰石裂变径迹年龄变化介于 2 5～ 1 3 0Ma之间 ,均低于其岩石形成年龄。昆北区和昆中区有着类似的演化趋势 ,即裂变径迹年龄随高程的增加而缓慢减小 ,平均隆升速率仅为 2 2 2m/Ma。与之不同 ,昆南区裂变径迹年龄与高程呈正比 ,变化率为 1 1m/Ma。昆南断裂带两侧地区截然相反的演化关系表明 ,昆南断裂带在进入陆内演化后所起的作用比昆中断裂带更为重要。

A series of samples were collected from about south-north section through Buqingshan and Dulan, eastern Kunlun mountains, China. The 41 apatite fission track ages(FTA) of these samples lie between 25.2 and 130.4 Ma, all of the apatite fission track ages are significantly younger than the host rocks. There are similar evolution trends for Middle-Kunlun zone and North-Kunlun zone, i.e. the FTA becomes less with slow increase of elevations and their uplifting rates are about 2.22 m/Ma. Differently, the FTA in South-Kunlun zone positively correlates to elevation, decreasing 11 m/Ma. It may be shown that South-Kunlun fault play a different and/or more important role on incontinent evolution than Middle-Kunlun fault.