准噶尔盆地西北缘吐孜阿克内沟八道湾组露头沉积特征及模式

以准噶尔盆地西北缘吐孜阿克内沟八道湾组野外露头追踪实测资料为基础,利用露头直观性识别厘定了中下侏罗统吐孜阿克内沟八道湾组层序地层界面.通过对岩性特征、沉积构造等相标志分析,对准噶尔盆地西北缘吐孜阿克内沟八道湾组沉积相特征进行解剖,识别出研究区共发育9种岩相和5种典型砾石质辫状河岩相序列组合,并判断出古气候经历了干旱向温带潮湿气候的转变.在此基础上,依据典型岩相标志分析,在吐孜阿克内沟八道湾组沉积中划分出辫状河道和河漫滩两种沉积相,进一步识别出河床滞留、心滩、泛滥平原、河漫沼泽和河漫湖泊等沉积微相,最终建立吐孜阿克内沟八道湾组的沉积序列,探讨了基准面不断上升的砾石质辫状河沉积体系模式.该研究成果可为准噶尔盆地勘探目标的优选提供地质依据,也可为该区油气勘探开发提供一定的指导.

Sedimentary Characteristics and Model of Outcrop the Badaowan Formation in Azitukeneigou , Northwestern Margin of the Junggar Basin

Through the field outcrop tracking data in the lower Junassic Badaowan in Azitukeneigou, northwest Junggar basin, the sequence stratigraphic boundary in the lower Junassic Badaowan in Azitukeneigou, northwest Junggar basin was determined by using outcrop intuitive identification. Combind with the analysis of lithologic characteristics, sedimentary structure and other facies markers, the sedimentary facies characteristics of in the lower Junassic Badaowan in Azitukeneigou, northwest Junggar basin, were dissected, eight types of lithofacies and five typical gravel braided river lithofacies sequenceassociations were identified in the study area, and judge the paleoclimate experienced drought transition to a temperate humid climate. On this basis, through the analysis of typical lithofacies markers , two types of sedimentary facies, braided channels and floodplains, were divided into the sediments of the Badaowan Formation Azitukeneigou, and further identified the sedimentary microfacies such as channel detention,flood plain, flood swamp and lake. Finally established the sedimentary sequence of the Badaowan Formation in Azitukeneigou and the model of gravel braided river depositional system with rising base level was discussed .The research results can provide a geological basis for the optimization of exploration targets in the Junggar Basin, and can also provide some guidance for oil and gas exploration and development in this area.