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现代海底普遍发育由内波、内潮汐引起的深水牵引流 ,内波、内潮汐不仅可形成各种厘米级的深水牵引流沉积构造 ,还可建造千米级的大型沉积物波。这种大型沉积物波既可沿斜坡向下迁移 ,也可沿斜坡向上迁移。在古代地层记录中已发现各种厘米级的内波、内潮汐沉积单元 ,但尚未发现内波成因的大型沉积物波。塔中地区中上奥陶统碎屑岩段内发育内波及内潮汐形成的各种牵引流沉积构造单元。通过详细的岩心观察 ,识别出 4种内波、内潮汐沉积微相类型及 5种基本垂向沉积层序。此外 ,通过地震剖面分析 ,在研究区中上奥陶统陆坡相中识别出顺坡向上迁移的大型沉积物波 ,该沉积物波的特征与现代海底发育的沉积物波的特征类似 ,运用内波理论可对其成因进行合理的解释。
The modern seafloor generally develops the deep-water traction flow caused by internal waves and internal tides. The internal waves and internal tides can not only form various centimeter-level deep-water traction flow sedimentary structures, but also construct large sediment waves of the order of kilometers. This large sediment wave can migrate either down the slope or up the slope. A variety of centimeter-level internal waves and tidal sedimentary units have been found in ancient stratigraphic records but large sediment waves of internal-wave origin have not yet been found. Various tidal flow sedimentary structural units formed by internal waves and internal tides are developed in middle-upper Ordovician clastic rocks in Tazhong area. Through detailed core observation, four types of internal waves, the types of internal tide sedimentary microfacies and five basic vertical sedimentary sequences were identified. In addition, through the seismic profile analysis, large-scale sedimentary waves migrating up the slope are identified in the Upper Ordovician slope facies in the study area. The characteristics of this sedimentary wave are similar to those of the sediment waves in modern submarine development. The theory of waves can reasonably explain its causes.