【摘要】 利用元素地球化学特征和地震几何构型特征,对塔里木盆地寒武-奥陶纪时期海平面升降变化规律进行了研究,建立了寒武-奥陶纪相对海平面变化曲线。研究发现,塔里木盆地寒武奥陶纪可划分出3个一级旋回,8个二级旋回,17个三级旋回和多期高频震荡旋回。其中,寒武纪经历了3期二级旋回,早中奥陶世经历了2期旋回。相对于寒武纪,早奥陶世海平面升幅较大。晚奥陶世经历了3期二级旋回:第一期处于海平面低位期,幅度较小;后二期快速上升,直达最高水位状态。海平面相对升降变化控制着盆地的沉积充填和层序的形成演化,其旋回性与盆地沉积作用的旋回性相一致,并可通过沉积相的演变表现出来。更多还原

【Abstract】 The eustatic sea-level change rule has been studied by using element geochemistry feature and seismic geometric configuration feature in the Cambrian-Ordovician in Tarim Basin,and the comparative sea-level change curve has been obtained,which can be divided into three first-grade cycles,eight second-grade cycles,seventeen third-grade cycles and more high frequency concussion cycles in the Cambrian-Ordovician in Tarim Basin.There occurred the second-grade eustatic sea-level change cycle three times during Cambrian and two times during the early Ordovician,and the extent of the sea-level rise in the early Ordovician is higher than that in Cambrian.In the middle-late Ordovician there occurred the second-grade eustatic sea-level change cycle three times,and the first time occurred at low system tract of sea level with small rise extent of the sea-level,but the sea-level rapidly reached the highest water level state in the later two times.The eustatic sea-level change controls on the basin sediment infilling and sequence formation evolution.The cyclicity of the sea-level changes are corresponded with the cyclicity of the basin sedimentation,and are represented by the sedimentary facies evolutions.更多还原