【摘要】 对阿尔金断裂两侧塔里木和柴达木盆地晚中生代以来沉积特征以及柴达木盆地反“S”型构造演化的研究表明 ,始新世中期以前塔里木盆地和柴达木盆地是一个连通的盆地 ,阿尔金走滑断裂对柴达木盆地内地表新时代的沉积和反“S”型构造形成的控制起始于始新世中期。在阿尔金断裂中段采集的受到走滑变形作用改造的侏罗纪地层和糜棱岩化加里东期花岗岩的样品 ,测出了激光微区4 0 Ar/ 3 9Ar等时线年龄为 89～ 92Ma。这说明阿尔金断裂在晚白垩世开始发生韧性走滑运动 ,而且走滑作用起始于地下深部 ,并伴有低级变质作用。地表的走滑响应明显地滞后于深部的起始走滑 ,说明走滑作用是从深部向地表扩展的。更多还原

【Abstract】 Studies of sedimentation since Late Mesozoic in Qaidam and Tarim basins suggest that Qaidam and Tarim basins must have bveen originally combined into one basin before Middle Eocene. Researches on the structural evolution of the reverse "S" structure belts in Qaidam basin show that the strike-slip movement of Altyn fault began at Middle Eocene, controlling the surface sedimentation and the formation of reverse “S” structure belts in Qaidam basin. The samples of deformed Jurassic rocks and Caledonian mylonitized granite from the middle part of Altyn fault give an 89～92 Ma isochron age group of 40Ar/ 39Ar laser microprobe. These ages suggest that the strike-slip movement started at depth, and gradually extended to the surface. The response of the strike-slip movement at the surface is clearly later than the initiation of this movement at depth.更多还原