Records of Migration and Ebb-Delta Breaching at Historic and Ancient Tidal Inlets along a River-Fed Paraglacial Barrier Island
Records of Migration and Ebb-Delta Breaching at Historic and Ancient Tidal Inlets along a River-Fed Paraglacial Barrier Island
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DOI：
10.2112/si75-46.1
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发表时间：
2016-08
期刊：
影响因子：
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通讯作者：
C. Hein;G. Fitzsimons;D. FitzGerald;A. Fallon
中科院分区：
文献类型：
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作者：
C. Hein;G. Fitzsimons;D. FitzGerald;A. Fallon
[摘要]海因菲茨西蒙斯，G. G.，菲茨杰拉德，D. M.，和法伦，A.R.，2016.沿着河流补给的近冰障壁岛的历史和古代潮汐入口的迁移和退潮三角洲破坏记录。In：Vila-Concejo，A.;布鲁斯，E.;肯尼迪，D.M.，和McCarroll，R.J.（eds.），第14届国际沿海研讨会论文集（澳大利亚悉尼）。沿海研究杂志，特刊，第75号，页。228-232.椰子溪（佛罗里达），ISSN 0749-0208。潮汐汊道将后障环境与沿海海洋联系起来，在沿岸和跨岸沉积物输运中起着主导作用。此外，在波浪主导的环境中，入口充填层序包括高达50%的障壁岩性体。本研究使用历史记录调查百年尺度周期的入口动态和屏障海岸线调整在梅里马克河入口（梅岛，缅因州湾）。地球物理和沉积学数据揭示了这些最近变化的几何和地层特征，并允许与附近3600年历史的入口填充序列中保存的类似记录进行比较。在沿岸搬运、沙嘴延伸和三角洲溃决过程的驱动下，梅里马克河口曾在普拉姆岛2.5 km长的河段上发生过活跃的迁移。19世纪中期的一次三角洲溃决事件导致前入口河道废弃，并在陆上焊接了一个大型沙洲，该沙洲发展到该岛北方1.5 km。在1800年代后期，入口通过突堤稳定下来。前入口通道的探地雷达剖面图和沉积物岩心捕捉到了破裂前变化的细节，包括向南和向陆迁移通道的向海偏转，以响应岸上的沙洲迁移和焊接。入口迁移，酒吧焊接，和退潮三角洲破坏类似的细节观察到的一个古老的入口在中央PI，位于7公里以南的地层记录。古代和历史序列之间的比较提供了线索，以破译复杂的入口动力学保存在地层和沉积记录。
ABSTRACT Hein, C.J.; Fitzsimons, G.G., FitzGerald, D.M., and Fallon, A.R., 2016. Records of Migration and Ebb-Delta Breaching at Historic and Ancient Tidal Inlets along a River-Fed Paraglacial Barrier Island. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 228-232. Coconut Creek (Florida), ISSN 0749-0208. Tidal inlets link backbarrier environments to the coastal ocean and play a dominant role in both longshore and cross-shore sediment transport. Additionally, inlet-fill sequences comprise up to 50% of barrier lithosomes in wave-dominated settings. This study uses historic records to investigate centennial-scale cycles of inlet dynamics and barrier shoreline adjustment at Merrimack River Inlet (Plum Island, Gulf of Maine). Geophysical and sedimentological data reveal geometric and stratigraphic signatures of these recent changes, and allow for comparison to similar records preserved within a nearby 3600-year-old inlet-fill sequence. Driven by processes of longshore transport, spit elongation and ebb-delta breaching, the Merrimack River Inlet once actively migrated across a 2.5-km long section of Plum Island. An ebb-delta breaching event in the mid-1800s caused abandonment of the former inlet channel and the onshore welding of a large sand bar, which developed into the northern 1.5 km of the island. The inlet stabilized by jetties in the late 1800s. Ground-penetrating radar profiles and sediment cores across this former inlet channel capture the details of changes prior to breaching, including the seaward deflection of the otherwise southerly and landward-migrating channel, in response to onshore bar migration and welding. Similar details of inlet migration, bar welding, and ebb-delta breaching are observed stratigraphic records of an ancient inlet in central PI, located 7 km to the south. Comparison between the ancient and historical sequences provides clues to decipher the complex inlet dynamics preserved in the stratigraphic and sedimentologic record.