Stratigraphy of the fluvial deposits of the Salado river basin, Buenos Aires Province: Lithology, chronology and paleoclimate

E. FUCKS; M.F. PISANO; R.A. HUARTE; C.V. DI LELLO; F. MARI; J.E.CARBONARI

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 60 p. 129 - 139

0895-9811

The regional landscape of the Salado depression is related to weathering, eolian and fluvial processesgenerated under different climatic conditions. Although during most of the Holocene the climatic conditionswere warm and humid, previously, a vast plain dominated by deflation processes and enhancedby weathering processes was developed in an arid environment. Fluvial deposits produced afterwardsare continuous and lithologically homogeneous, which allows differentiation and characterization of theentire stratigraphic sequence. The stratigraphic units of this area, closely related to the paleoclimaticconditions, are recognized and characterized. Three lithostratigraphic units of fluvial origin (Members)and two paleosols have been differentiated. The first ones were grouped in the Lujan Formation. Some ofthe units are related to other ones previously recognized in this area (La Chumbiada Member and LaPelada Geosol), but others have no similarity or relationship with previously known units (Gorch andPuente Las Gaviotas Members, and Frigorífico Belgrano Geosol). Radiocarbon ages suggest that the fluvialsequences were deposited after the glacial maximum, corresponding to MIS 1, except for the basal levelsof the lower member which is late Late Pleistocene. Although the general paleoclimatic conditions wererelated to warm and humid climate, events related to water deficits were also recognized, which could berelated to the Younger Dryas, the middle Holocene and the late Holocene.