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Late Quaternary paleosols, stratigraphy and landscape evolution in the Northern Pampa, Argentina

2006; Cambridge University Press; Volume: 66; Issue: 1 Linguagem: Inglês

10.1016/j.yqres.2006.01.001

1096-0287

Rob A. Kemp, Marcelo Zárate, Phillip Toms, Matthew King, Jorge A. Sanabria, Graciella Arguello,

Pleistocene-Era Hominins and Archaeology

Abstract The field properties, micromorphology, grain-size, geochemistry, and optically stimulated luminescence (OSL) ages of two late Quaternary sections have been used to reconstruct the sequence of pedosedimentary processes and to provide insights into landscape evolution in part of the Northern Pampa of Argentina. Paleosols developed in paludal sediments adjacent to the Paraná river at Baradero and in loess at Lozada can both be correlated and linked to other sites, thus enabling for the first time the tentative recognition and tracing of a diachronous soil stratigraphic unit that probably spans the equivalent of at least part of marine oxygen isotope stage (OIS) 5. The paleosol at Lozada was truncated and buried beneath fluvial sediments during the time span of OIS 4 and 3. Eolian gradually replaced paludal inputs at Baradero over this period, and there were also two clearly defined breaks in sedimentation and development of paleosols. The period corresponding to OIS 2 was marked by significant loess accumulation at both sites with accretion continuing into the mid-Holocene only at Lozada. The more developed nature of the surface soil at Baradero probably reflects a combination of a moister climate and a longer soil-forming interval.