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从中生代到新生代,准噶尔盆地腹部地区连续沉积,缺少腹部地区的样品,因此准噶尔地区晚古生代构造演化的研究常集中于盆地周围的褶皱造山带。本文通过对早二叠纪—晚石炭纪钻井岩心样品的地球化学、岩石学特征进行研究。结果表明:1)许多钻井的不同层位中,都发育着表明水上喷发环境的褐色凝灰岩;2)准噶尔盆地腹部早二叠纪—晚石炭纪火山岩主要是碱性玄武岩、安山岩及少量的流纹岩,样品的大部分以高碱为特征,反映了喷发于陆上增厚地壳的构造背景;3)岩心观察、薄片鉴定及主量和微量元素的分析结果表明,晚古生代准噶尔盆地腹部属于大陆构造背景。石炭系火山岩的底部也许存在许多的古老陆块基底。
From the Mesozoic to the Cenozoic, the sediments of the Junggar Basin belonged to a continuous area, lacking the samples from the belly areas. Therefore, the study of the Late Paleozoic tectonic evolution in the Junggar area often concentrated in the fold orogen around the basin. In this paper, the geochemical and petrological characteristics of the samples from the Early Permian-Late Carboniferous drilling core were studied. The results show that: 1) the brown tuffs that indicate the environment of water eruption are developed in many layers of the drilling; 2) the Early Permian-Late Carboniferous volcanic rocks in the abdomen of Junggar Basin are mainly alkaline basalt, andesite and a small amount of rift Most of the rocks and samples are characterized by high alkali, which reflects the tectonic background of the eruption on the inland thickened crust. 3) Core observation, thin section identification and analysis of major and trace elements show that the Late Paleozoic Junggar Basin belonged to continental tectonic setting . There may be many ancient landmass bottoms at the bottom of Carboniferous volcanic rocks.