Abstract
Mahu Sag, one of the most oil and gas bearing sags in Junggar basin, is in the northwestern margin of the basin. On gentle slope region of the sag, a serial of large scale coarse fan delta deposits were developed in Triassic Baikouquan Formation. In order to understand the petrology characters of conglomerates in Baikouquan Formation, based on lots of cores, grain size analysis, normal thin sections, casting thin sections, scanning electron photomicrographs, mineral composition identifications, clay mineral and bulk composition identifications of X-ray diffraction, were comparatively studied for Xiazijie and Huangyangquan fan-delta in Mahu Sag. Mineral composition of conglomerates is main tuff, while eurite, dacite, rhyolite, andesite and granite are common. However, more tuff and granite, less eurite and andesite in Xiazijie fan-delta, there is no rhyolite in Huangyangquan fan-delta. Kaolinization and chloritization of conglomerates are ubiquitous in the formation. The content of chlorite and kaolinite is higher in Xiazijie fan-delta, with lower illite-smectite and illite. There is less feldspar of clastic and more calcite of cement in Xiazijie fan-delta.
Highlights
The Mahu Depression is one of the six major hydrocarbon-bearing foreland sags located at the northwestern margin of Junggar Basin, China (Tang et al, 2014)
On the basis of the data of rock particle size analysis, mineral composition identification, X-ray diffraction of clay mineral composition and whole rock analysis, this paper combines the observation of ordinary slice, cast slice and scanning electron microscope observation to carry out relevant summary on the characteristics of various rock mineral contents of the two fan-delta bodies
On the hanging wall of thrust fault, Zaire and Hala’alatmountains’ carboniferous and the firestone in the Permian Jiamuhe Formation were supplied sufficient material sources for Mahu Depression during the Early Triassic (Qu et al, 2015). One part of these coarse sediments accumulated at the margin of depression by the interaction of gravity formed alluvial fans, while others moved further to the center of the basin and enter into the shallow water of Mahu Depression, resulting in a series of proximal fan-delta aprons in the gentle slope zone (Kuang et al, 2014)
Summary
The Mahu Depression is one of the six major hydrocarbon-bearing foreland sags located at the northwestern margin of Junggar Basin, China (Tang et al, 2014). The large coarse-grained proximal fan-delta depositional systems developed in the Triassic Baikouquan Formation under the gentle slope background This paper focuses on a large number of laboratory data of drilling coring and various rock analyses, and takes Xiazijie fan-delta and Huangyangquan fan-delta as examples. On this basis, this paper further makes a comparative analysis and research from macro to micro on the petrological characteristics of glutenite reservoirs of Baikouquan Formation in Mahu Depression. On the basis of the data of rock particle size analysis, mineral composition identification, X-ray diffraction of clay mineral composition and whole rock analysis, this paper combines the observation of ordinary slice, cast slice and scanning electron microscope observation to carry out relevant summary on the characteristics of various rock mineral contents of the two fan-delta bodies
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
