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通常认为牵引毡或碎屑流内部颗粒相互碰撞产生的分散应力是形成浊积岩中反递变层的原因。假定剪切牵引毡成层且内部粒径向上增大,则此牵引毡沉积后就可产生反递变层。基于粗粒碎屑的搬运速度小于细粒碎屑的搬运速度这一事实,提出了反递变层的另一种形成模式。浊流中沉积物粒径的充分均匀混合将经历纵向的粒度分异作用,使得粗粒碎屑搬运滞后。如给定位置处的沉积作用发生于最粗碎屑到达该位置之前,最终沉积产物的下部将呈反递变。相似的作用过程也可在火山灰流沉积中形成反递变层。浊流头部速度通常只有体部(头部稍后位置)速度的0.83倍,所以能跟上浊流前部的最粗碎屑的搬运速度 V_(sed)约等于0.83 U_(body)。如果存在更大粒径的碎屑,它们将滞后于头部,从而产生反递变。如果最粗碎屑跟得上浊流头部(或更快)或直到最粗碎屑到达该位置后才发生沉积作用,此模式将不适用。假使最大流速线下存在一对数速度剖面,就可以计算出特定粒径悬浮颗粒的搬运速度,其可表示为流速的分子形式。这样就可由反递变层底部最粗颗粒的沉降速度推导出流动强度(剪切速度)的上限:u_*≤4w_(init)。当反递变浊积岩的沉积作用在浊流头部刚通过就立刻发生时,u_*≈4w_(init)。
It is generally believed that the dispersion stress created by the collision of particles inside the traction felt or debris flow with each other is responsible for the formation of the degenerative layer in the turbidite. Given that the strands of traction felt are stratified and the internal particle size increases upwardly, a degenerative layer can be created upon deposition of the traction felt. Based on the fact that the handling speed of coarse-grained debris is less than that of fine-grained debris, another mode of formation of the anti-retrogradation layer is proposed. The uniform and uniform mixing of the sediment particle size in the turbidity stream will undergo vertical grain size fractionation, which will result in lagged handling of coarse-grained debris. If the deposition at a given location occurs before the most coarse debris reaches that location, the lower portion of the final deposition product will retrograde. Similar processes can also create retrograded layers in volcanic ash deposits. The turbidity head velocity is usually only 0.83 times the velocity of the body (head later) so the trailing speed V sed of the weakest debris that can follow the turbidity front equals approximately 0.83 U body. If larger size crumbs are present, they will lag behind the head, creating anti-reversion. This mode will not apply if the most coarse debris follows the turbidity head (or faster) or does not sediment until the most coarse debris reaches this location. If there is a logarithmic velocity profile under the maximum flow line, the transport speed of a particular particle size suspended particle can be calculated, which can be expressed as the molecular form of the flow rate. Thus, the upper limit of the flow strength (shear rate) can be derived from the settling velocity of the coarsest particles at the bottom of the deformable layer: u_ * ≤4w_ (init). U_ * ≈4w_ (init) when the detritus turbidite deposition occurs immediately after the turbidity head has just passed.