Delta bathymetry, seismic data and near-surface sediment sampling on modern deltas with significant wave, tidal or marine current influence betray a double clinoform architecture with a bridging subaqueous platform. Much of the muddy portion of river-sediment discharge that reaches the coastline bypasses the mouth bar/shoreline clinoform and is deposited, eroded, re-suspended and stored in the distant subaqueous portion of deltas. The sediment stored on the prograding slope of the subaqueous delta is predominantly muddy and heterolithic sediment gravity flows, a diagnostic feature of the prograding and rapidly accumulating subaqueous delta. The subaqueous delta sometimes becomes markedly skewed offshore to run parallel to the shoreline, a routing often aided by shelf currents. Early marine researchers tackled the problem of how sediment from the river reaches so far out (commonly 100 km) on the shelf; they showed that negatively and positively buoyant river plumes, and reworked delta front/shoreface sediments are dispersed out onto the subaqueous delta, greatly assisted by the action of waves, tides and especially friction-reducing fluid mud on the seabed of the subaqueous platform. Documentation of the growth of modern subaqueous deltas has contributed to recent progress in understanding mud dispersal on shelves. Equivalent understanding of ancient deltas, however, has lagged behind.

中文翻译：

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地层记录中的水下三角洲：追赶海洋地质学家的脚步


对受波浪、潮汐或海流影响的现代三角洲进行的三角洲测深、地震数据和近地表沉积物采样揭示了具有桥接水下平台的双斜形结构。到达海岸线的河流沉积物排放的大部分泥质部分绕过河口坝/海岸线斜坡，沉积、侵蚀、重新悬浮并储存在三角洲的遥远水下部分。水下三角洲进积斜坡上沉积的沉积物主要是泥质和异石质沉积物重力流，这是水下三角洲进积和快速堆积的诊断特征。水下三角洲有时会在近海处明显倾斜，与海岸线平行，这种路线通常受到陆架流的帮助。早期的海洋研究人员解决了河流沉积物如何到达大陆架上如此远（通常100公里）的问题；他们表明，负浮力和正浮力河流羽流以及改造后的三角洲前缘/岸面沉积物被分散到水下三角洲上，这在很大程度上得益于水下平台海底的波浪、潮汐和特别是减少摩擦的流体泥浆的作用。现代水下三角洲增长的记录有助于最近在了解陆架上的泥浆扩散方面取得进展。然而，对古代三角洲的同等理解却落后了。