Editorial. Advances in the Quaternary of the de la Plata River Basin, South America - Editorial

IRIONDO, MARTIN; KRÖHLING, DANIELA

QUATERNARY INTERNATIONAL

Pergamon Press.

Lugar: Oxford; Año: 2004 vol. 114 p. 1 - 2

1040-6182

The great De la Plata River basin (3,100,000 km2) is formed by the Parana and Uruguay basins. It is largely a Quaternary system, because it was shaped by orogenic and epirogenic movements that occurred in Pliocene times. The broad pattern of the basin is formed by the mobile Andean belt in the west, Mesozoic-Paleozoic rocks in the north and east, and Quaternary sedimentsin the central and southern lowlands. The climate of the region is dominated by the general circulation of the atmosphere. The ITCZ reaches the north of the basin in December and January; the southern Westerlies indirectly influence the climate in winter via anticyclonic circulation. Polar waves rarely occur and snowfall is unknown in most of the basin. The basin links tropical regions with subtropical/temperate plains characterized by loess-paleosols sequences, a geographic pattern which permits long time-series correlation.The influence of the De la Plata basin in the South Atlantic during the Quaternary has been important. If one considers the present sediment discharge of 250 million metric tons per year as representative, and a hypothetical accumulation area of 1,000,000km2 of platform and oceanic bottom, a mean thickness of more than 400 m of sediment was accumulated in two millionyears. Even considering the secular compaction, the dimensions are impressive. The amount of dissolved salts contributed to the ocean is on the same order ofmagnitude.