塔里木盆地考库亚泥盆系沉积相

The Devonian Sedimentary Facies of Kokuya, Tarim Basin

考库亚泥盆系剖面位于塔里木盆地西南缘,出露中泥盆统阿尔塔西群上部和上泥盆统全部,总厚797.8m。该地泥盆系自下而上可划分为浪控陆棚相、前三角洲亚相、浪控三角洲前缘亚相、海岸过渡带亚相和扇三角洲陆上平原亚相5个主要相段,显示出清楚的向上变粗层序。文中论述了一个由浪控陆棚到扇三角洲水上平原的完整的推进层序,分析了不同沉积环境的沉积物粒度特征及地球化学特征,并对古地理格局进行了讨论。

The Devonian section of kokuya is situated in the southwestern margin of Tarim Basin. The upper part of outcropped Middle Devonian Altaxi group, together with the whole Upper Devonian, has a total thickness of 797.8m. The Devonian section of Kokuya can be divided into five principal facies zones, wave-controlled continental shelf facies, prodelta subfacies, wave- controlled delta front subfacies, shoreline transitional zone subfacies and fan-delta onshore plain subfacies, showing a distinct coarsening-upward sequence. A complete progradational sequence developing from the wave-controlled continental shelf to the fan- delta onshore plain is described, and the grain-size distribution and the geochemical characteristics of the sediment in different depositional environments are analyzed. Also, a discussion of the palaeogeographical pattern is presented.