The red beds of the Qigu Formation in the Yongjin area,situated on the southern margin of the Junggar Ba-sin,display significant oil and gas potential.Investigating the genesis of the red beds within this specific region holds practical,theoretical,and economic significance as it addresses an existing research gap concerning the continental red beds of the Qigu Formation.This paper presents a comprehensive analysis of the red beds in the Yongjin area,focusing on their genesis and geological significance.The study integrates data from previous research on continental red beds and combines various analytical techniques,including whole rock testing,scanning electron microscopy(SEM)observa-tions,and core examinations of the Qigu Formation's mudstone.The results demonstrate that the mudstones in the Yongjin area primarily comprise quartz,albitite,and muscovite,and there is no sidermangite.Notably,both red and green mudstone samples contain potassium feldspar,while hematite is exclusively found in the red samples.The clay mineral assemblage in the mudstone is characterized by high illite content,a significant presence of mixed-layer illite/smectite,limited chlorite and montmorillonite,and a lack of kaolinite.It is believed that the red beds in the lower part of Qigu Formation in Yongjin area is the result of exposed oxidation,while the red beds in the top part is the result of resu-perposed diving oxidation on the basis of the local red beds.The main chromic mineral is hematite.The occurrence of nu-merous red beds within the Qigu Formation in the Yongjin area and the middle part of the north margin of the Tianshan Mountains is likely influenced by global climate cycles and tectonic interactions.
关键词
永进地区/齐古组/红层成因/准噶尔盆地南缘
Key words
Yongjin area/Qigu Formation/Genesis of Red Beds/South margin of Junggar Basin
维普
万方数据