Beach-ridge development in Lake Michigan: Shoreline behavior in response to quasi-periodic lake-level events
Beach-ridge development in Lake Michigan: Shoreline behavior in response to quasi-periodic lake-level events
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DOI：
10.1016/0025-3227(95)00110-7
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发表时间：
1995-12
期刊：
影响因子：
2.9
通讯作者：
T. Thompson;S. J. Baedke
中科院分区：
文献类型：
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作者：
T. Thompson;S. J. Baedke
弧形滩脊的平原在五大湖部分地区的沿海海湾中很常见。尽管密歇根湖盆地的许多海湾在大小和形状、可用沉积物类型和供应、沉积前坡度和地形以及水文状况方面存在差异，但它们在海滩脊发育和地貌方面的相似之处是显而易见的。这些相似性主要是30~600年和0.5~3.7m的三个准周期湖水位变化的产物。这三个湖水位变化的相互作用可以用Curray(1964)图(水位变化速率与沉积物供应速率)来表示。图中任何海岸线的位置和海岸线正在经历的行为类型都是这三种变化相互作用的产物。在密歇根湖的两端(托勒斯顿海滩和汤普森海湾)，出现了两个全新世晚期的大型滨海平原。在过去的2600个历年中，这两个地区呈现出相似的海滩山脊发育模式。也就是说，这两个地区大约每30年形成一次海滩脊。由4至6个滩脊组成的群组反映了约150年的较长期湖平面变化。只有在大约600年的最大持续时间变化期间，这两个地区才有所不同。上升到1700卡年的B.P.高位导致密歇根湖北部海滩脊的侵蚀回到2800卡年BP。在密歇根湖南部，在这一湖高水位期间没有发生侵蚀。这两个地区之间海岸线发展的差异与向海岸线提供泥沙的速度有关。作为密歇根湖南半部的沉淀池，南岸平原在晚全新世后期获得了比北岸平原更大的泥沙通量，并产生了连续的滩脊发育记录。
Strandplains of arcuate beach ridges are common in coastal embayments in parts of the Great Lakes. Similarities in beach-ridge development and geomorphology are recognizable in many of the embayments in the Lake Michigan basin despite differences in size and shape, available sediment type and supply, predepositional slope and topography, and hydrographic regime between the embayments. These similarities are primarily a product of three scales of quasiperiodic lake-level variation ranging in time from 30 to 600 years and in water level change from 0.5 to 3.7 m. The interaction of these three lake-level variations can be represented on a Curray (1964) diagram (rate of water level change versus rate of sediment supply). The position of any shoreline on the diagram and the type of behavior the shoreline is experiencing is a product of the interaction of the three variations. Two large Strandplains of late Holocene beach ridges occur at opposite ends of Lake Michigan (Toleston Beach and Thompson embayment). The two areas exhibit similar patterns of beach-ridge development for the past 2600 calendar years. That is, both areas form beach ridges about every 30 years. Groups of 4 to 6 beach ridges reflect a longer-term lake-level variation of about 150 years. Only during the largest variation of about 600 years in duration do the two areas differ. The rise to the 1700 cal yr B.P. high caused the erosion of beach ridges back to 2800 cal yrs B.P. in northern Lake Michigan. In southern Lake Michigan, no erosion occurred during this lake level high. Differences in shoreline development between the two areas are related to the rate of sediment supply to the shorelines. As the sediment sink for the southern half of Lake Michigan, the southern strandplain received a greater sediment flux than the northern strandplain during the latter part of the late Holocene and produced a continuous record of beach-ridge development.