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闽西南地区早三叠世溪口组 (T1x)是一套复杂的深水沉积 ,包括浊积岩、砂质等深积岩及外来的孤立滑塌岩块 .深水浊积岩可分为 5种相和 7种亚相 ,分别属于上扇、中扇和下扇环境的 5种相组合 ;砂质等深积岩是改造浊积岩而形成的 ,多以孤立的薄层发育于浊积岩中 ,内部发育典型的牵引流沉积构造 ,但垂向上不构成任何固定的层序如Bouma序列 ,其古水流方向与浊流流向垂直 ;在局部地区 ,于该组中下部发育的一些大的鲕粒灰岩块体 ,是从浅水边缘滑动至深水盆地的 .上述 3类沉积物的时空分布表明 ,早三叠世早期研究区存在完整的由浅海到半深海 -深海的被动陆缘 ,当时的陆坡倾向南东 ,这一时期为海平面上升期 ,海平面的上升及孤立滑塌岩块的发育可能暗示这一时期海域的逐渐收缩和消亡 .
The Early Triassic Xikou Formation (T1x) in southwestern Fujian is a complex set of deepwater sediments, including turbidite, sandy and other isolated slump rock blocks. There are five types of deep-water turbidite: Facies and seven kinds of subfacies belong to five kinds of combination of upper fan, middle fan and lower fan environment, respectively. Sedimentary facies are formed by alteration of turbidite, and mostly isolated turbidite In the interior, the typical traction flow sedimentary structure is developed internally, but does not form any fixed sequence such as the Bouma sequence in the vertical direction. The paleocurrent direction is perpendicular to the turbidity flow direction. In some areas, some large oolites developed in the middle and lower part of the group The granulite blocks slide from the shallow water margin to the deepwater basin.The temporal and spatial distribution of the above three types of sediments shows that there is a complete passive continental margin from shallow sea to semi-deep sea and deep sea in the early Triassic study area, The slope tends to the south east during this period, which is the sea level rising period. The rise of sea level and the development of isolated slump rock mass may suggest the gradual contraction and demise of sea area during this period.