Facebook
Twitter
YouTube
Instagram
    • español
    • English
  • Contacto
  •  
    • español
    • English
  • Mi Cuenta
Acerca deAutoresTítulosTemasColeccionesComunidades☰
JavaScript is disabled for your browser. Some features of this site may not work without it.
Ver ítem 
    xmlui.general.dspace_homeCentros e Institutos de InvestigaciónCIRN. Centro de Investigaciones de Recursos NaturalesInstituto de SuelosArtículos científicosxmlui.ArtifactBrowser.ItemViewer.trail
  • Inicio
  • Centros e Institutos de Investigación
  • CIRN. Centro de Investigaciones de Recursos Naturales
  • Instituto de Suelos
  • Artículos científicos
  • Ver ítem

Late quaternary paleosol records from sutropical (38°S) to tropical (16°S) South America and palaeoclimatic implications

Resumen
Loess and palaeosols in the subtropical lowlands of South America (∼23–38°S) have a large potential to serve as archives of Late Quaternary environmental and climate changes. At present, mean annual precipitation generally decreases from N to S and from E to W, though with a complex seasonal pattern with austral summer rainfall related to the monsoonal circulation and with austral winter rainfall related to the SE-trades. In this paper, we present results [ver mas...]
Loess and palaeosols in the subtropical lowlands of South America (∼23–38°S) have a large potential to serve as archives of Late Quaternary environmental and climate changes. At present, mean annual precipitation generally decreases from N to S and from E to W, though with a complex seasonal pattern with austral summer rainfall related to the monsoonal circulation and with austral winter rainfall related to the SE-trades. In this paper, we present results of multiproxy geochemical analyses from three representative eolian/alluvial soil profiles along a S–N transect aiming at the reconstruction of past climate changes: (i) profile “Chasico” at the southern border of the subtropics (38°S), (ii) “D4” in Misiones at the northern border of the subtropics (27°S), and, for comparison, (iii) “Laguna Sucuara” in the savannas of the Bolivian lowlands (16°S). Our results show that before ∼16 ka BP, conditions were likely very cold and dry. Except for in “D4”, loess or soils are not preserved due to rather scarce vegetation cover and resultant deflation. In “Chasico”, accumulation of sands (directly overlying the Tertiary) starts only during the Late Glacial, indicating increasing temperatures and increased monsoonal precipitation (coinciding with the “Tauca” wet phase on the Altiplano). In “D4”, a palaeosol is preserved below the Late Glacial sediments and the deflation hiatus. This palaeosol is dated to ∼40 ka BP and documents an earlier, but less intensive (southward reaching) phase of monsoonal precipitation (“Inca Huasi” on the Altiplano). Whereas the seasonality during the Late Glacial seems to have been very pronounced, conditions for organic matter production and preservation became much more favourable at “Chasico” and “D4” during the Early Holocene. We suggest that extra-tropical winter precipitation played a more important role than before and than today. Between ∼7.5 and 3 ka BP, the expansion of C4 plants along the S–N transect suggests increasing aridity, probably due to a weakening of the extra-tropical circulation in combination with a relatively weak monsoonal circulation. Only after ∼3 ka BP climate became more humid again due to the re-strengthening of the monsoon. [Cerrar]
Thumbnail
Autor
Zech, Wolfgang;   Zech, MIchael;   Zech, Roland;   Peinneman, Néstor;   Morras, Hector;   Moretti, Lucas Martin;   Ogle, Neil;   Fucks, M.;   Kalim, R.M.;   Schad, P.;   Glaser, B.;  
Fuente
Quaternary International 196 (1–2) : 107-120 (March 2009)
Fecha
2009-03-01
Editorial
Elsevier
ISSN
1040-6182
URI
http://hdl.handle.net/20.500.12123/21038
https://www.sciencedirect.com/science/article/pii/S1040618208000050
DOI
https://doi.org/10.1016/j.quaint.2008.01.005
Formato
pdf
Tipo de documento
artículo
Palabras Claves
América del Sur; South America; Cambio Climático; Climate Change; Cuaternario; Quaternary; Late Quaternary; Cuaternario Tardío;
Derechos de acceso
Restringido
Descargar
Compartir
  • Compartir
    Facebook Email Twitter Mendeley
Excepto donde se diga explicitamente, este item se publica bajo la siguiente descripción: Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Unported (CC BY-NC-SA 2.5)
Metadatos
Mostrar el registro completo del ítem