Aeolian Origin of the Pampean Lakes of Central Argentina, Southern South America: A Quaternary Wind Legacy to a Wet-Dry Changing Landscape
摘要
The aeolian origin of the depressions that host the shallow lakes of the Pampa plain is reviewed based on previous investigations and new analysis of the relationship between patterns of shallow lakes/wetlands and types of aeolian landforms. Own previously published and unpublished field observations and geological studies were combined with new investigations using satellite images, DEM-based topographic configurations, and morphometric analysis. The dominant Late Pleistocene aeolian morphogenesis in the whole Pampa plain, combined with pervasive aeolian activity during the Holocene in Western and Central Southern Pampa plain, strongly controls the presence of numerous shallow lakes that expand during periods of hydrological excess. Remote sensing analysis reveals that the distribution, abundance, shape, and size of Pampean lakes and wetlands follow a general pattern that is strongly related to the type of the aeolian landforms of the Pampa plain. Past and present wind processes have been a key factor for the formation of lake basins by means of deflation (pans), migration of diverse types of parabolic and blowout dunes, and damming of the fluvial networks. The Pampa plain's Quaternary aeolian landscape, which experienced alternating wet and dry modes with varying timeframes and spatial cover, leaves a record that should be taken into account while analysing the varied environmental/paleoenvironmental and ecological features of the lake systems.