苏北平原在发育过程中,遗留着一系列南北向分布的古砂堤(古称“砂冈”)。成为现今研究本区历史海岸线变迁的重要地貌标志。对于砂堤形成的年代,国内有关学者已有过不同程度的研究。陈吉余教授对于苏北砂堤的形成,归结为全新世海侵达最大高度后,在波浪作用下,泥沙横向运动堆积成的岸外砂堤; During the development of the Northern Jiangsu Plain, a series of ancient sand dikes (ancient name “Sandang”) distributed in north-south direction left behind. It becomes an important landform sign to study the vicissitudes of historical coastline in this area. For the formation of sand embankment, domestic scholars have had different degrees of research. Professor Chen Jiyu for the formation of sand banks in northern Jiangsu, boils down to the Holocene sea reaches the maximum height, under the action of waves, the sediment horizontal movement of the accumulation of the outer sand bank;