Horn Island, one of the two most stable barriers along the Mississippi-Alabama chain (Cat, East and West Ship, Horn, West Petit Bois, Petit Bois, and Dauphin), provides critical habitat, helps regulate estuarine conditions in the Mississippi Sound, and reduces wave energy and storm surge before they reach the mainland shore. However, important details of the formation and evolution of the island in response to sea-level rise, storms, and antecedent geology remain unclear. This study integrates 2200 km of high-resolution geophysical data, 35 sediment cores, and 18 radiocarbon ages to better understand the geologic history of the island. Incised valleys of the Biloxi and Pascagoula Rivers underlie Horn Island and played a profound role in the evolution of the system. Within the incised valleys, sandy paleochannel deposits represent potential sediment sources during island development. Scour associated with wave and tidal ravinement processes liberated sand from the paleochannels and along with numerous other sizable sand sources on the shelf contributed to the formation and continued maintenance of Horn Island. Based on radiocarbon ages, transgressive ephemeral islands/shoals with no preserved shoreface existed at least 8000 cal yr BP and were frequently overwashed when sea-level rise rates were ~ 4–5 mm/yr. Approximately 5000 cal yr BP, coinciding with a deceleration in sea-level rise to about 1.4 mm/yr and attendant increased sand supply, radiocarbon ages associated with Horn Island's barrier complex and lower shoreface indicate a period of island stabilization. Seismic and sediment core data show a long history of westward lateral migration by longshore currents through tidal ravinement and inlet fill. Subsurface sand packages associated with tidal inlet fill and paleochannels are available for ravinement and may be important sand sources for Horn Island to maintain subaerial exposure with the expected accelerated future sea-level rise.

霍恩岛（Horn Island）是密西西比-阿拉巴马州链上两个最稳定的屏障之一（猫，东西船，霍恩，西珀蒂博伊斯，珀蒂博伊斯和多芬），提供了重要的栖息地，有助于调节密西西比湾的河口条件，并减少波浪能和风暴潮到达大陆海岸之前的时间。然而，关于海平面上升，风暴和前期地质的岛屿形成和演变的重要细节仍不清楚。这项研究整合了2200 km的高分辨率地球物理数据，35个沉积物岩心和18个放射性碳年龄，以更好地了解该岛的地质历史。比洛克西河和帕斯卡古拉河切开的山谷位于霍恩岛下方，并在该系统的演变中发挥了重要作用。在切开的山谷中，沙质古河道沉积物代表了岛屿发展过程中的潜在沉积物来源。与浪潮和潮汐作用相联系的冲刷作用使沙粒从古河道中释放出来，并与架子上许多其他相当大的沙源一起促进了霍恩岛的形成和持续维护。根据放射性碳的年龄，没有保存海岸面的海侵短暂岛/浅滩存在至少8000 cal yr BP，当海平面上升速率约为4-5 mm / yr时经常被过度冲洗。大约5,000 cal yr BP，与海平面上升到每年约1.4 mm / yr的减速以及随之而来的沙子供应增加，与Horn Island的屏障复合体和较低的海岸面相关的放射性碳年龄表明了一个岛稳定时期。地震和沉积物核心数据显示了由潮汐流和进水口引起的沿岸流向西向横向迁移的悠久历史。与潮汐入口填充物和古河道相关的地下沙层可用于耕作，并且可能是Horn Island保持海底暴露的重要沙源，并有望加速未来海平面上升。