大青山晚白垩世以来的隆升历史  

Uplift History of the Daqing Mountain since the Late Cretaceous

作　　者：吴中海[1] 吴珍汉[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081

出　　处：《地球学报》2003年第3期205-210,共6页Acta Geoscientica Sinica

基　　金：国土资源基础研究项目"首都圈新生代构造 地貌演化及环境灾害效应"(编号 :992 0 2 6);国家攀登项目 (编号 :95 - 专-0 5;95 - 预 -40 )资助。

摘　　要：根据以裂变径迹年龄为主的热年代学方法和大青山地形剖面和盆地沉积资料分析 ,认为大青山地区晚侏罗世发生大型板内挤压变形之后在晚白垩世进入伸展构造控制的构造活动阶段。在伸展背景下 ,大青山主要经历了晚白垩世整体隆升 剥蚀和始新世以来的造山带伸展裂解引发的差异升降 剥蚀过程。造成大青山约 6km的剥蚀量。在大青山伸展、塌陷、裂解过程中由于山 盆间的阶段性差异升降运动形成了大青山中的四期夷平面和其下的山前侵蚀台地以及邻区盆地沉积体系中的相对应的多期沉积间断。最终形成大青山地区现今盆 山构造 地貌格局。控制山脉隆升的大青山山前正断层始新世以来的平均活动速率为 0 .2～ 0 .3mm/a。Thermochronological dating (K-Ar and fission track) shows that the Daqing Mountain underwent three stages of rapid uplift since late Jurassic. The first stage occurred at approximately 138 Ma and was in accordance with the time of Daqing Mountain thrusting. The second occurred at approximately 100～90 Ma and caused the denudation of approximately 3 km thickness of the mountain. The third occurred at 50 Ma and also denuded approximately 3 km thickness of the mountain, consistent with the rifting of Hetao basin. The topographic and stratigraphic analysis of the Daqing Mountain and Hetao graben show that the Daqing Mountain has four planation surfaces consistent with the depositional intervals in Hetao graben. This indicates that they were formed respectively in late Cretaceous-Paleocene, Eocene, Oligocene and Miocene. The mean active rate of normal faults along the southern margin of the Daqing Mountain is 0.2～0.3 mm/a.

关 键 词：大青山 晚白垩世 伸展构造控制 始新世 造山带 盆-山构造 裂变径迹 夷平面 

分 类 号：P542.1[天文地球—构造地质学] P534.53[天文地球—地质学]