Abstract Quaternary sea level and climate changes can promote spatio-temporal shifts in the morphology of coastal eolian depositional systems. A shift of depositional features such as from sandsheets to dunefields occurs as response to a disequilibrium condition in the system promoted by changes in accumulation space and sediment supply balance. On the other hand, the eolian system migration, with maintenance of morphological patterns, points to an equilibrium conservation under minor variations in the external controlling factors of the system. The Santa Catarina coast in southern Brazil hosts widespread active and stabilized eolian depositional systems with varied morphology. In this study, geomorphologic and stratigraphic changes of eolian deposits of the southern coast of Santa Catarina were constrained by optically stimulated luminescence (OSL) dating. This allowed to assess how coastal eolian systems responded to late Quaternary climate and sea level changes. Eolian sandsheets initiated around 22 ka ago, during the Last Glacial Maximum (LGM), and persisted during most of the deglacial period under conditions characterized by sea level lowstand, wider exposition of shelf sediments, more continental and drier climate and scarcer vegetation cover in the study setting. The shift from eolian sandsheets to dunefields occurred approximately at 6 ka ago and marks the establishment of coastal conditions in the study setting. The development of dunefields since the middle Holocene would result from eolian system disequilibrium in response to a condition characterized by sea level highstand, wetter climate and denser vegetation cover. The maintenance of a dunefield morphology since 6 ka ago, despite its onshore migration, indicates a new equilibrium between accumulation space and sediment supply. Sandsheets evolved to dunefields around 6 ka ago when the coastline stabilized and the accumulation space was limited by onshore vegetation growth, favoring eolian sediment aggradation. The precipitation ridge in the inner margin of the dunefield has been successively stabilized, abandoned and repositioned seaward, accompanying the coastal progradation since 4 ka ago. The decreasing migration rate of dunefields since 4 ka ago is attributed to rainfall reduction, which deplete fluvial sediment supply to coastal systems and, therefore, slow down the coastal progradation rate.

中文翻译：

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冰消期气候和相对海平面变化迫使巴西南部海岸从风成沙地转变为沙丘

摘要 第四纪海平面和气候变化可以促进沿海风积沉积系统形态的时空变化。沉积特征的转变，例如从沙地到沙丘，是对系统中由堆积空间和沉积物供应平衡的变化所促进的不平衡条件的响应。另一方面，风成系统迁移，随着形态模式的维持，在系统外部控制因素的微小变化下指向平衡守恒。巴西南部的圣卡塔琳娜海岸拥有广泛的活跃和稳定的风成沉积系统，具有不同的形态。在这项研究中，圣卡塔琳娜州南部海岸风成沉积物的地貌和地层变化受到光激发光 (OSL) 测年的限制。这允许评估沿海风成系统如何响应晚第四纪气候和海平面变化。风成砂层始于大约 22 ka 前的末次盛冰期 (LGM)，并在以海平面低位、陆架沉积物暴露范围更广、大陆性和干燥气候更多、植被覆盖稀少为特征的条件下持续存在学习环境。从风成沙床到沙丘的转变大约发生在 6 ka 前，标志着研究环境中沿海条件的建立。中全新世以来沙丘的发展是由于风积系统不平衡，以应对以海平面高位、气候湿润和植被更密集为特征的条件。尽管有陆上迁移，但自 6 ka 以来沙丘地貌的维持表明堆积空间和沉积物供应之间出现了新的平衡。大约 6 ka 前，当海岸线趋于稳定，堆积空间受到陆上植被生长的限制，有利于风积沉积物聚集时，沙床演变为沙丘。4 ka以来，随着海岸进积，沙丘内缘降水脊先后稳定、废弃和重新定位向海。4 ka 以来沙丘迁移率下降的原因是降雨减少，