塔里木盆地上泥盆统-三叠系层序地层及控制因素分析

ANALYSIS ON THE UPPER DEVONIAN-TRIASSIC SEQUENCE STRATIGRAPHY IN THE TARIM BASIN AND ITS CONTROLLING FACTORS

塔里木盆地泥盆统－ 三叠系层 序地层可划分为 ２ 个巨层序、５ 个超层序、１２ 个层序。晚泥盆 世－ 三叠纪区域大地构造演化经历了“古 新疆板块”的局部裂解与 再拼贴的过程 ，塔里木盆地 则经历了晚泥 盆世－ 早二叠 世弧后裂谷和 晚二叠世－ 三叠 纪前陆盆地两个阶 段。巨层序Ⅰ为弧后裂谷演化阶段 的产物，其中超层序Ⅰ Ａ 代表克拉 通内坳陷盆地的沉积，超 层序Ⅰ Ｂ 代表弧后 克拉通内裂谷盆地 充填沉积。巨层序Ⅱ为前陆盆地演 化阶段的沉积，其中超层序Ⅱ Ａ 代表周缘前陆 盆地的充填沉 积，超层序Ⅱ Ｂ 和 超层序Ⅱ Ｃ 是内陆 坳陷盆地的沉积。研究表明，构造 作用在大部分Ⅲ级层序形成中起着 决定性作用，只是在构造相对稳定的 晚泥盆世－ 石炭纪的被动 大陆边缘和克拉通盆地演化时期， 全球海平面的升降变化才对其层序 的形成起了较大的作用。

The Devonian-Triassic stratigraphic sequences in the Tarim Basin can be divided into two megasequences, five supersequences and twelve sequences. The Late Devonian-Triassic regional geotectonic evolution underwent the local splitting and rematching of 'the paleo Xinjiang plate', and the Tarim Basin involved the Late Devonian-Early Permian back arc rift and the Late Permian-Triassic foreland basin two stages. The megasequence Ⅰ is the product of the back arc rift evolutionary stage, in which the supersequence Ⅰ A represents the deposit of downwarped basins in the craton and the supersequence Ⅰ B represents the basin filling deposit of rift in the bacd arc craton. The megasequence Ⅱ is the deposit of the foreland basin evolutionary stage, in which the supersequence Ⅱ A represents the filled deposit of peripheral foreland basins and the supersequence Ⅱ B adn Ⅱ C are the deposit of inland downwarped basins. Research reveals that tectonic process played a decisive role in the formation of most Ⅲ order sequences. Only in the evolutionary period of the Late Devonian-Carboniferous passive continental marginal and craton basins, during which tectonics are relatively stable, did the global eustacy act a greater part in the formation of the sequences.