三角洲前缘滑塌浊积岩形成过程初探

Preliminary Study on the Formation of Fluxoturbidite in Front of Delta

通过室内水槽实验模拟了三角洲前缘滑塌浊积岩的形成过程,总结出四种滑塌浊积岩类型,即无触发机制的天然重力滑塌、地震诱发作用产生的滑塌、波浪作用产生的滑塌和与底形相关的砂岩透镜体。实验结果表明,外界触发机制是形成三角洲前缘滑塌浊积岩的重要条件,底形的变化结合波浪、地震等外界触发机制的作用更容易在三角洲前缘形成滑塌浊积体。此外,被破坏和改造的三角洲前缘更易找到滑塌浊积体;相反,形态规则、保存完好的三角洲前缘反而不利于滑塌浊积岩的形成。

According to the in door flume experiment simulations, the formation of fluxoturbidite in front of delta is studied. It is summarized that there are four kinds of fluxoturbidite in front of delta. They are the fluxoturbidite with no trigger action and one associated with seismic process, one with wave action and sandstone lens correlative with landform. The experiments suggest that trigger actions are the most important conditions to form fluxoturbidite in front of delta. Together with wave action and seismic process, the change of landform can promote forming fluxoturbidite. Also, the fluxoturbidite can be found easily in front of the delta where the delta front has been destroyed and rebuilt. In contrast, the regular and good reserved delta front is disadvantaged to form fluxoturbidite.