冲积扇发育过程中砾石颗粒对砂坝和沟流的控制作用——基于冲积扇水槽模拟实验

发布时间：2018-05-30 10:34

  本文选题：砾石颗粒 + 冲积扇模拟实验　； 参考：《断块油气田》2017年03期

【摘要】：通过观察和记录冲积扇自旋回沉积模拟实验,研究在冲积扇的发育过程中,砾石颗粒对冲积扇在沉积过程中的控制机理。研究表明:在同一期洪水期的中期—后期,在冲积扇扇根片流带中,沟流发育的优势方向与砾石颗粒初期分布有着重要关系,同时砾石颗粒的分布还控制着沟流改道;在冲积扇的扇中发育过程中,由于砾石颗粒是在牵引流的搬运作用下运动,因此对沟道的控制作用便更多体现在对沟道形态的改造与砂坝的形成上。通过对比冲积扇剖面中出现的多期辫流水道叠置、砂坝和沟道的分布状态,就能够验证实验过程中冲积扇表面发生的现象。在实验过程中,冲积扇形成的规模是与碎屑流的动力、携带沉积物和沉积时间呈正比关系。在碎屑流的动力与携带的沉积物相对没有变化的稳定期内,扇根的砂坝与沟流、扇中的沟道都与砾石颗粒的作用密切相关。
[Abstract]:By observing and recording the simulation experiment of alluvial fan spin-cycle deposition, the control mechanism of gravel particles on alluvial fan during the development of alluvial fan was studied. The results show that the dominant direction of trench flow development is closely related to the initial distribution of gravel particles, and the distribution of gravel particles also controls the diversion of channel flow in the middle to late flood period of the same period. During the development of alluvial fan, the gravel particles move under the action of traction flow, so the control of channel is more reflected in the transformation of channel shape and the formation of sand dam. By comparing the distribution of multi-stage braided channel, sand dam and channel in the alluvial fan profile, the phenomenon on the surface of the alluvial fan can be verified. In the experimental process, the scale of alluvial fan formation is proportional to the power of the clastic flow, and the sediment carrying is proportional to the deposition time. During the stable period in which the dynamics of the clastic flow and the sediment carried by it are relatively unchanged, the sand dam at the fan root, the channel in the fan and the channel in the fan are all closely related to the action of the gravel particles.
【作者单位】： 长江大学地球科学学院;中国石油大学地球科学学院油气资源与探测国家重点实验室;
【基金】：国家自然科学基金项目“同生逆断层对冲积扇沉积构型的控制作用机理——冲积扇沉积过程分析与沉积过程研究”(41372116)
【分类号】：P512.2
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本文编号：1954983