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采用地质、地震资料,对准噶尔盆地陆西地区上石炭统进行了层序划分与对比,并对上石炭统上层序火山岩岩性、岩相进行了分析。研究认为,陆西地区上石炭统可分为上、下2个层序,上层序的顶、底界均为区域性不整合面,在地震剖面上具有上超/削蚀的反射终端类型。上层序的岩石类型主要有玄武岩、安山岩、沉凝灰岩、凝灰岩、火山角砾岩、英安岩等。火山岩岩相有火山通道相、爆发相、溢流相和火山沉积相。火山通道相主要根据地震剖面上的锥状体来识别;爆发相岩性主要为火山角砾岩与凝灰岩,电性特征为高电阻率、高速度,伽玛值变化大,但以低伽玛为主,具有变振幅、断续或杂乱反射特征;溢流相岩性主要为玄武岩、安山岩、英安岩等,电性特征为高电阻率、高速度,伽玛值变化大,具有中—强振幅、较连续反射特征;火山沉积相主要由正常火山碎屑岩、正常沉积岩、火山碎屑沉积岩等组成,电性特征表现为高伽玛、低电阻率、低速度,具有强振幅、高连续反射特征。爆发相主要分布于达巴松凸起—夏盐凸起西部和东部;火山沉积相主要分布于夏盐凸起中部、玛湖凹陷南部;其他地区则为溢流相分布区。
Based on the geological and seismic data, the sequence stratigraphic division and contrast of the Upper Carboniferous in Luxi area, Junggar Basin, are carried out. The lithology and lithofacies of the Upper Carboniferous volcanic rocks are also analyzed. The study shows that the Upper Carboniferous in Luxi area can be divided into upper and lower two sequences. The top and bottom boundaries of the upper sequence are all regional unconformities, and there are reflection terminal types of up-over / erosion in the seismic profile. The upper sequence of rock types are basalt, andesite, tuff, tuff, volcanic breccia, dacite and so on. Volcanic rock facies are volcanic channel facies, eruption phase, overflow phase and volcanic sedimentary facies. The volcanic channel facies are mainly identified by the cones on the seismic section. The lithofacies in the eruption phase are mainly volcanic breccias and tuffs. The electrical characteristics are high resistivity, high velocity and large variation of gamma values. However, Mainly characterized by variable amplitude, discontinuity or random reflection. The lithology of overflow phase is mainly basalt, andesite and dacite. The electrical characteristics are high resistivity, high velocity, great variation of gamma value, Strong amplitude and continuous reflection features. The volcanic sedimentary facies are mainly composed of normal pyroclastic rocks, normal sedimentary rocks and pyroclastic sedimentary rocks. The electrical characteristics are high gamma, low resistivity, low velocity, strong amplitude and high Continuous reflection features. The eruptions are mainly distributed in the west and east of the Tabashen uplift - Xiayan salient. The volcanic sedimentary facies are mainly distributed in the middle of the Xiayan salient and in the southern Mahu depression. The other areas are the distribution of overflow phase.