论文部分内容阅读
塔里木盆地西南缘K2-E海相含碳酸盐岩地层中可识别出七种类型的高频旋回层序,主要有潮下缓坡型、台地型、台地边缘型碳酸盐旋回层序及以碎屑岩为主的潮间-潮上型旋回层序。平面上,不同类型高频旋回层序成为特定古地理背景下台地碳酸盐沉积体系、滨岸沉积体系和冲积沉积体系沉积层序的代表。纵向上,各类高频旋回层序的有序叠加,其类型的变化反映了沉积环境、沉积相的演变过程。研究结果表明,研究区各类高频旋回层序下部单元至上部单元微相的转变是受高频率海平面变化的影响,低频率海平面升降控制了高频旋回层序的叠加形式,造成沉积环境由下至上滨岸→碳酸盐台地→滨岸→河流的变化。正是由于不同周期海平面变化旋回的叠加形成了塔里木盆地西南缘K2-E的复合海平面变化旋回层序。
There are seven types of high-frequency cyclic sequences identified in the K2-E marine carbonate-bearing strata in the southwestern margin of the Tarim Basin. They are mainly the subtidal gentle-slope, platform-type and platform margin carbonate cycles and Clastic-mainly tidal-tidal cycle sequence. In the plane, different types of high-frequency cycles are representative of sedimentary sequences of platform carbonate sedimentation system and alluvial sedimentary system in a specific paleogeographic setting. Longitudinally, various types of high-frequency cycles sequence superimposed, the type of change reflects the depositional environment, the evolution of sedimentary facies. The results show that the transformation from the lower unit to the upper unit of various high-frequency cycles in the study area is affected by the high frequency sea level changes. The low frequency sea level rise and fall control the superimposition of high frequency cycle sequences, resulting in deposition Environment from the bottom to the coast → carbonate platform → coast → river changes. It is because of the superposition of sea-level cycles in different periods that formed the complex sea level-changing gyration sequence of K2-E in the southwestern margin of the Tarim Basin.