利用锆石裂变径迹研究漠河盆地隆升过程
The application of zircon fission track to the study of the uplifting process in the Mohe Basin
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摘要: 通过对漠河盆地内32件样品的锆石裂变径迹进行详细分析,锆石单颗粒径迹年龄最大值为143.9±18.7Ma,最小年龄为58±12.1Ma,峰值年龄为92~98Ma和132~138Ma。结合盆地断裂展布及大地构造背景,认为漠河盆地在95Ma和135Ma发生了2次强隆升过程。结合盆地断裂系统、构造特征及区域地质背景,认为自晚侏罗世以来盆地形成受到蒙古-鄂霍次克海碰撞关闭和古太平洋板块俯冲碰撞双重作用的影响,盆地中晚侏罗世(135Ma左右)处于南北向挤压背景,形成东西向展布的前陆盆地;白垩纪中期,盆地处于伸展构造背景,属东北(同)大陆裂谷系的一部分。白垩纪中晚期(95Ma左右),漠河盆地由拉张环境再一次变为挤压环境,盆地形成了又一次的强隆升过程。Abstract: By analyzing 32 zircon fission track samples from Mohe Basin, the authors have found that the maximum fission track age is 143.9±18.7Ma, the minimum age is 58±12.1Ma, and the peak ages are 92~98Ma and 132~138Ma. The authors hold the opinion that Mohe Basin experienced two strong uplift processes at 95Ma and 135Ma, based on considering the basin fault system and geotectonic background. The authors hold that Mohe Basin was in a SN-trending compression environment from the Late Jurassic (135Ma), and was in an extensional environment during Middle Cretaceous. Then the basin was in a SN-trending compression environment once again in the Late Cretaceous, leading to another strong uplift.