Southern Santa Catarina coast hosts widespread Quaternary eolian deposits with varied morphology, both active and inactive. Changes in morphological patterns of eolian depositional systems are controlled by sediment supply and accumulation space, which in turn are sensitive to climate, relative sea level (RSL), coastline behavior and coastal physiography. In the coastal sector between Campo Bom and Araranguá, eolian sandsheets, inactive and active dunefields occur side by side. These eolian sandsheets were formed at least since the Last Glacial Maximum (LGM ~22 ka), under low RSL, with a wide exposition of inner shelf sandy sediments to deflation and local eolian re-deposition as sandsheet deposits, in a continental (drier) setting due to its distancing from the coastline (around 160 km at that time). Sandsheet formation was terminated around 5 ka ago, with the beginning of a wetter period in the study area due to SAMS intensification and high and stable RSL, with a stable coastline and enhanced effects of rainfall changes in eolian sediment supply. The termination of eolian sandsheets coincides with development of a new eolian morphology, successive dunefields with precipitation ridges and barchanoid chains, from 6 ka up to 2 ka. The successive younger precipitation ridges towards the current coastline were modulate by coastal progradation over the last 4 ka. Changes in rainfall during 7-4 ka ago increased the fluvial discharge and the supply of terrigenous sediments to the coast under a RSL highstand condition, favoring higher rates of coastline regression and decreasing the eolian system sand supply, creating a pattern of successive abandonment of precipitation ridges. This pattern is an adjustment of the eolian system position as an equilibrium response to coastline regression under a constant rate of RSL fall. The maintenance of dunefields in the last 6 ka, as we have an inactive dunefield formed between 6-2 ka and an active dunefield, shows that coastline regression promoted the seaward migration of the eolian systems, but was not enough to shift the eolian depositional style again.
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