Genesis and distribution of the Late Pleistocene and Holocene loess of Argentina: a regional approximation

An overview of the current state of knowledge of the loess of Argentina is presented. The spatial distribution of the loess (typical or reworked) is described and, in particular, reference is made to the relationship between landforms and superficial materials in the sub-tropical loess region. The description of extrinsic and intrinsic characteristics demonstrates the influences of regional factors in loess distribution and the existence of a SW-NE loess transport path throughout Argentine territory. The available dating confirms the age of the superficial loess as Pleistocene and Holocene. It is pointed out that the temporal interval of deposition of the Late Pleistocene loess coincides with the highest dust concentrations as shown in the ice core records at both poles. The prominent influence of volcanic materials. affecting not only the mineral composition of the loess but also the genesis and evolution of the loess-palaeosol sequences, is emphasised. Finally, the importance of the palaeosols as indicators of palaeoenvironmental conditions is clearly demonstrated by the descriptions of outcrops in the pre-Andean valleys of north-western Argentina. (C) 2001 Elsevier Science Ltd and INQUA. All rights reserved.