柴达木盆地西部北区新近纪沉积体系演化及其控制因素

Analysis on sedimentary systems evolution and their control factors on Neogene,northwest Qaidam Basin

柴达木盆地西部北区新近纪发育阿尔金斜坡西段物源和阿尔金斜坡东段物源,其中,西段物源包括干柴沟水系、咸水泉水系、红沟子水系和月牙山水系,主要发育陡坡型扇三角洲—浊积扇—湖泊沉积体系;东段物源包括红三旱一号水系和牛鼻子梁水系,主要发育缓坡型扇三角洲—滨浅湖滩坝沉积体系;湖盆内部主要发育内源碳酸盐岩—膏岩沉积体系。研究认为,阿尔金断裂及其派生的各次级断裂活动的阶段性、多期性与复杂性控制了位于湖盆边缘的各类沉积体系的发育与演化;而内源碳酸盐岩—膏岩沉积体系的发育与演化则受控于湖盆内部发育的多个水下低凸起和多个沉积中心并存的古地理背景。

There are west sedimentary source and east sedimentary source developed in the altun slope in Neogene in northwest Qaidam Basin,the west sedimentary source includes Ganchaigou water system,Xianshuiquan water system,Honggouzi water system and Yueyashan water system which mainly develop fan delta and turbidite fan and lake depositional system that are mainly steep slope type.The east sedimentary source includes Hongsanhanyihao water system and Niubiziliang water system which mainly develop the fan delta and bar and lake depositional system that are gentle slope type.There are carbonate and gypsum sedimentary systems developing in the basin center.For all kinds of sedimentary systems,which lie in the edge of the basin,its development and e-volution are controlled by the altun rupture and its derived sub-ruptures activities by the study.These ruptures' activities often have many features such as stages,multi-cycles and complexities.But the development and evolution of carbonate and gypsum sedimentary system are controlled by the ancient geography relief which has many low uplifts and multiple sedimentary centers in the basin.