准噶尔盆地北缘山前带沉积物源及相模式研究——以哈拉阿拉特山前缘春晖探区为例

Sedimentary Provenance and Facies Model of Piedmont Belt in the Northern Margin of Junggar Basin:A Case from the Chunhui exploration area of Hala'alt front edge

准噶尔盆地北缘山前带是我国目前油气勘探的一个重点领域。为了深入探讨山前带沉积研究中存在的疑问,以准北缘哈拉阿拉特山山前春晖探区为对象,综合利用岩芯、钻测井资料及大量沉积学实验手段,对其侏罗系八道湾组沉积特征及物源方向进行研究,证实了该区粗碎屑沉积物主要来自北西方向的哈山山区,属于典型的近源沉积。通过构造、沉积演化史分析与现代沉积考察相结合的方法,总结出了山前带近源砾石高磨圆度的两类成因,分别对应于砾石形成期的滨海环境以及再搬运沉积期的湿地扇环境,最终建立了春晖探区八道湾组湿润型冲积扇沉积相模式。

At present,piedmont belt in the northern margin of Junggar Basin is one of the key zone in oil-gas exploration fields. For the purpose of explaining the question in the piedmont belt sedimentary research,with the Chunhui exploration area of Hala'alt front edge in the northern margin of Junggar Basin for target,the sedimentary characteristics and provenance of Jurassic Badaowan Formation was studied comprehensively using methods of core,drilling and logging data,and a large number of sedimentologic experiment. The results have confirmed that the coarse clastic sediments belong to the typical proximal deposit,which are mainly from northwest Hala'alt mountains. By analyzing tectonic and depositional histories,combining with recent sediment investigation,two origins of high-psephicity nearsource gravel from piedmont zone were concluded,which formed in the littoral environment stage and humid fan environment of retransported stage,respectively. In the end,the humid fan facies model of Jurassic Badaowan Formation in Chunhui exploration area was established.