【摘要】 前陆盆地由于其独特的构造和沉积背景形成不同的层序地层格架样式.以准噶尔盆地车排子地区为例,详细分析了造山带前缘隆起斜坡带层序样式.在准西车排子地区中新生界主要目的层段(下白垩统吐谷鲁群、古近系安集海河组、新近系沙湾组和塔西河组)充填沉积中识别出5条主要等时界面,据界面的性质和级别划分出一级层序2个,二级层序组3个,三级层序4个.受前陆盆地造山带前缘隆起斜坡带独特的沉积背景及多幕逆冲构造活动作用过程的控制,准西车排子地区中新界各三级层序具有二元沉积结构特征,仅发育低位和湖扩体系域.逆冲挤压期发育低位粗碎屑沉积,应力松弛期发育湖扩细碎屑沉积.低位下切谷、大型扇三角洲和湖扩滩坝砂是准西车排子地区的有利储集砂体及勘探目标.更多还原

【Abstract】 Special sequence stratigraphic framework formed in the foreland basin due to its unique tectonic and sedimentary background.In this paper,the sequence patterns in orogenic front uplift belt are discussed taking an example of the Chepaizi area,western Junggar basin.Five key chronohorizons are identified in Mesozoic-Cenozoic sedimentary intervals(Tugulu Group of Lower Crataceous,Anjihaihe Group of Paleogene,Shawan Group and Taxihe Group of Neogene)in the study area.According to the features and orders of the sequence boundaries,two first-order sequences,three second-order sequences and four third-order sequences are divided.Controlled by the special orogenic front uplift slope depositional setting in foreland basin and multiple episodic thrusting processes,the Mesozoic-Cenozoic sequences show two contrasting segments of sequence architecture with only lowstand system tract and transgressive system tract in the Chepaizi area.Coarser grain deposits developed in lowstand system tract during thrusting period,and finer grain deposits developed in transgressive system tract during tectonic relaxing period.The lowstand incised valleys,large scale fan deltas and transgressive beach sandbars are the mainly favorable reservoir rocks and exploration targets.更多还原