Deposits of flows transitional between turbidity current and debris flow
Deposits of flows transitional between turbidity current and debris flow
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DOI：
10.1130/g30059a.1
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发表时间：
2009-11
期刊：
影响因子：
5.8
通讯作者：
E. Sumner;P. Talling;L. Amy
中科院分区：
文献类型：
--
作者：
E. Sumner;P. Talling;L. Amy
人们对海底沉积物重力流与其沉积物特征之间的关系知之甚少。环形水槽实验用于研究沉积动力学和逐渐减弱的沉积物沉积流。具有固定砂含量（10 vol%）和可变泥含量（0-17 vol%）的快速减速流（>3 m/s）仅产生四种沉积类型。如果沉积开始时流动是湍流，或者泥浆流体没有足够的强度来悬浮沙子，那么就会形成带有泥盖的干净沙子，类似于浊流沉积物（浊积岩）。如果泥含量低（300秒），干净的沙子可能含有结构。带有泥盖的未级配泥砂，类似于泥石流沉积物（碎石），如果在沙子沉积之前水流变成层流，就会形成。干净的沙子上覆盖着未级配的泥砂和由过渡流或泥浆悬浮液中沙子的后期沉降形成的泥盖。这些沉积物类似于神秘的海底流沉积物，称为链接的碎屑-浊积岩。这些实验为根据海底沉积物流动的沉积特征推断流动类型。
The relationship between submarine sediment gravity flows and the character of their deposits is poorly understood. Annular flume experiments were used to investigate the depositional dynamics and deposits of waning sediment-laden flows. Decelerating fast (>3 m/s) flows with fixed sand content (10 vol%) and variable mud content (0–17 vol%) resulted in only four deposit types. Clean sand with a mud cap that resembled a turbidity current deposit (turbidite) formed if the flow was turbulent when deposition began, or if the muddy fluid had insufficient strength to suspend the sand. The clean sand could contain structures if mud content was low ( 300 s. Ungraded muddy sand with a mud cap that resembled a debris-flow deposit (debrite) formed if the flow became laminar before sand could deposit. Clean sand overlain by ungraded muddy sand and a mud cap formed either from a transitional flow or by late-stage settling of sand from a muddy suspension. These deposits resemble enigmatic submarine flow deposits called linked debrite-turbidites. The experiments provide a basis for inferring flow type from deposit character for submarine sediment-laden flows.