柴窝铺盆地及其北缘地区中新生代沉积岩源区构造背景和物源属性研究

沉积岩中的碎屑组分及主量元素、微量元素和稀土元素可以反映物源信息,广泛应用于沉积源区的确定、构造背景的分析。通过对柴窝铺盆地及北缘地区侏罗纪至古近纪沉积地层的碎屑岩岩石学和地球化学分析,揭示了盆地沉积岩的原岩来自上地壳,岩性以长英质岩石为主,并混合进了部分安山质及基性岩石。源区构造背景为活动大陆边缘,因其原岩是在大陆岛弧环境下形成的,所以部分构造背景显示为大陆岛弧。本次研究不仅可以为柴窝铺盆地及北天山的构造演化过程及其机制提供有力证据,并且对柴窝铺油气勘探具有一定指导意义。

A study of tectonic setting and provenance of Mesozoic and Cenozoic sedimentary rocks in Chaiwopu Basin and its northern margin

Such factors as detrital composition, major elements, trace elements and rare earth elements of sedimentary rocks can reflect the information of provenance, and are hence widely used to determine sedimentary provenance type and tectonic setting. An analysis of detrital petrology and geochemistry shows that the provenance of the basin around west Bogda came from the upper earth crust, and felsic rocks were predominant, with the mixture of a small portion of andsitic and basic rocks. The tectonic setting of this area should be active continental margin; nevertheless, as the original rock was formed in a continental island arc environment, a part of the tectonic background displays the continental arc environment. This research provides evidence for studying the structural evolution of the Chaiwopu Basin and North Tianshan Mountains, and is also of great significance for the exploration of oil and gas resources in Chaiwopu Basin and Junggar Basin.