中、新生代阿尔金走滑断裂系构造运动的沉积学揭示  

Sedimentology Revealment to Meso-Cenzoic Tectonic Movement Process of Altun Strike-slip Fault

作　　者：刘兴旺[1] 郑建京[1] 杨鑫[1,2] 孙国强[1] 苏龙[1] 王亚东[1] 

机构地区：[1]中国科学院地质与地球物理研究所油气资源研究重点实验室,甘肃兰州730000 [2]中国科学院研究生院,北京100049

出　　处：《天然气地球科学》2012年第1期119-128,共10页Natural Gas Geoscience

基　　金：石油化工联合基金项目(编号:40739902)资助

摘　　要：将阿尔金走滑大断裂及与其相邻发育的几条展布方向一致、运动方式接近的断裂带统称为阿尔金走滑断裂系。通过对各断裂带组成、延伸规模、活动时期和活动方式,阿尔金走滑断裂系中、新生代沉积层系的岩相古地理,盆地上部沉积层系地震数据解释和柴西坳陷古近系沉积岩裂变径迹等方面的研究,结合遥感地质学等手段,探讨阿尔金走滑断裂系中、新生代构造运动学过程。研究认为,印支期阿尔金走滑断裂系总体构造格局处于相对隆起状态,区域上基本未接受三叠纪沉积,表现为剥蚀阶段。受燕山运动影响,在区域微弱拉张作用下,阿尔金走滑断裂系在侏罗纪相对整体沉降并开始接受侏罗纪沉积,形成大阿尔金湖。至燕山运动中晚期,受新特提斯构造域关闭的影响,形成区域范围的构造抬升,大阿尔金湖消亡。燕山运动末期发育区域范围的左旋走滑运动,阿尔金走滑大断裂带形成。喜马拉雅运动开始后,塔东南坳陷和柴达木盆地整体进入相对拗陷期,古近纪地层厚度展布特征揭示出,沉积区的古地理特征表现为阿尔金断隆开始抬升,阿尔金走滑大断裂带构造运动强度逐渐加强,尤其在古近纪晚期以来这一特征十分明显。受此构造事件影响,新生代民丰坳陷主要受阿尔金走滑大断裂和北民丰凸起的控制形成挤压挠曲型走滑拉分盆地,若羌坳陷主要受控于车尔臣河断裂、且末—若羌断裂和阿尔金北缘断裂形成雁列型拉分盆地。In this paper, we consider the Altun strikeslip fault zone and its surrounding fault zones with uniformed spread direction and similar motion mode to be the Altun strikeslip fault system. Based on composition of these fault zones, extension scale, active period, activity behavior as well as lithofacies paleogeography of the MesoCenzoic sedimentary strata in the area of the Altun strikeslip fault system, seismic data interpretation of the upper sedimentary strata of the basin, and the fissiontrack dating of the Paleogene System sedimentary rock in the Chaixi depression and remote sensing geology, we discuss the tectonic movements process of The Altun strikeslip fault. The results suggest that the general tectonic movement pattern of the Altun strikeslip fault system is in the uplift condition under the IndoChina movement action, and there is lack of the Jurassic deposition as denudation phase. With influence of Yanshain movement and week extension tectonics,the Altun strikeslip fault systems accepted the Jurassic deposition in the relative whole settlement,and the big Altun Lake was formed. At the middle and late Yanshan Period, the close of new Tethyan tectonic domain made the regional tectonic uplift,resulting in the big Altun lake disappeared. During the end of the Yanshan Period,the leftlateral strike slip motion was developed within a regional range,and the Altun strikeslip fault was formed. After the Himalayan period, the southeast depression and the Qaidam basin came into the relative depression stage. The Paleocene thick sediments reveal that the Altun fault uplift began to raise,and the tectonic process of the Altun strikeslip fault intensified gradually,especially at the later of the Paleogene. With influence of this tectonic event, the Cenozoic Minfeng depression as a strikeslip pullapart basin was formed by compressive deformation between the Altun strikeslip fault and the north Minfeng salient,and the Ruoqiang depression as a pullapart basin was formed by compressive action among the Cheerchenhe River

关 键 词：走滑断裂系 新生代构造 阿尔金 沉积学 构造运动 断裂带构造 岩相古地理 地震数据解释 

分 类 号：TE122[石油与天然气工程—油气勘探]