This paper presents an analysis of the transport conditions of a storm deposit (i.e. tempestite) produced by a non-local cyclone. Observations and analysis of ‘sand to boulder’ transport and washover deposition in March 2018 at Gaulding Cay Quarry, Eleuthera, The Bahamas, confirm that swell waves can cause coastal change and affect the depositional record >1000 km from the storm centre. Drone video, news reporting, deposit stratigraphy, grain-size measurements and wave data were all used to define three phases of washover fan construction: an aggradational phase associated with base-level rise as the quarry filled with water; a progradational phase associated with quasi-constant base-level; and fan incision tied to base level fall as discharge through an outlet channel exceeded input discharge by overtopping waves. Washover fan location was controlled by antecedent topography and represented only a fraction of the swell-impacted coastline. Sand and boulders were transported simultaneously, forming a complex poorly sorted deposit. Drone video, bedrock erosion and sediment-transport estimates all indicated that overwash exceeded sediment availability. As a result, the measured washover fan was estimated to be an order of magnitude smaller than its potential volume if conditions had been transport-limited. This study highlights the importance of pre-event topography and independent measures of event duration on accurately reconstructing storm properties from the sedimentary record, as well as the challenges in reconstructing storm location, and therefore storm intensity and frequency, from sedimentary deposits alone.

中文翻译：

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非局地风暴造成的现代沿海风暴沉积：巴哈马伊柳塞拉的沙子和巨石膨胀产生的运输

本文分析了非局地气旋产生的风暴沉积物（即风暴岩）的运输条件。2018 年 3 月在巴哈马伊柳塞拉 Gaulding Cay 采石场对“沙子到巨石”运输和冲刷沉积的观察和分析证实，涌浪会导致海岸变化并影响距风暴中心 1000 公里以上的沉积记录。无人机视频、新闻报道、沉积地层学、粒度测量和波浪数据都被用来定义冲洗风机建设的三个阶段：随着采石场充满水，与基础水平上升相关的累积阶段；与准恒定基础水平相关的推进阶段；当通过出口通道的排放量超过输入排放量时，与底面相连的扇形切口下降。冲刷扇位置受先前地形控制，仅代表受膨胀影响的海岸线的一小部分。沙子和巨石同时运输，形成了一个复杂的分类不良的沉积物。无人机视频、基岩侵蚀和沉积物运输估计都表明，过度冲洗超过了沉积物的可用性。因此，如果条件受到运输限制，则测得的冲洗风扇估计比其潜在体积小一个数量级。本研究强调了事件前地形和事件持续时间的独立测量对于从沉积记录准确重建风暴特性的重要性，以及仅从沉积沉积物重建风暴位置以及风暴强度和频率的挑战。