Late Pleistocene-Holocene dust record in the Pampa plain

Abstract

Aeolian sediments are a primary component of the Pampa plain substratum. Its extension (i.e., from ~ 23° S to 38° S) and thickness (i.e., ~ 50 m at some places), reflects the implications of the role of wind processes on the Pampa region. The Pampean loess is the thickest and most extensive surficial aeolian deposit in the Southern Hemisphere and constitutes the parent material of the arable lands in the region. During the last decades, the scientific interest of these deposits has increased, recognising their paleoenvironmental importance since they preserve terrestrial loess-paleosols sequences. These records of paleo-dust, represent one of the few Quaternary sediments that provide a direct record of past atmospheric circulation, allowing paleoclimatic reconstructions. In this chapter, we discuss the importance of the dust cycle in the Pampa region, different methods to determine the origin of dust together with paleoclimatic inferences for the Late Pleistocene-Early Holocene. The latter were deduced from high-resolution studies developed at three loess sections at the Northern Pampa plain. The possibility of correlating indicators obtained in aeolian loess deposits with lacustrine ones makes these paleoclimatic records a powerful tool for characterising the past climate in southern South America.