Environmental magnetism of a paleosoil in the Lujan Formation (Luján, Buenos Aires Province), comparison with other areas in the province and palaeoclimatic considerations

En:

Rev. Asoc. Geol. Argent. 2002;57(4):451-462

Fecha:

2002

Formato:

application/pdf

Tipo de documento:

info:eu-repo/semantics/article
info:ar-repo/semantics/artículo
info:eu-repo/semantics/publishedVersion

Descriptores:

Environmental magnetism -  Paleoclimates -  Quaternary -  Rock magnetism -  geomagnetism -  paleoclimate -  paleomagnetism -  paleosol -  Quaternary

Descripción:

An environmental magnetic study of mainly fluvial "postpampean sediments" assigned to the Lujan Formation (Luján, Buenos Aires Province, Argentina) was carried out. The results obtained suggest a depletion of detrital ferromagnetic minerals during the pedogenetic processes. A characteristic magnetic signal can be distinguished in Holocene paleosols and soils of both eolian and fluvial "post-Pampean sediments" (Fm. Luján and Fm. La Postrera . This signal is analogous to that determined in loessic Pampean sediments assigned to the Buenos Aires Formation. It is inferred that the depletion of detrital ferromagnetic minerals is a general process in the Chacopampean area. This process may be associated with the genesis of a superparamagnetic fraction (SP), which could indicate dry periods during the climatic event. The depletion could also be associated with the genesis of a high coercitivy fraction, analogous with those determined in paleosols in the Pampean loess.
Fil:Orgeira, M.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Walther, A.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Tófalo, R.O. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Vásquez, C.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Identificador(es):

http://hdl.handle.net/20.500.12110/paper_00044822_v57_n4_p451_Orgeira

Derechos:

info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/2.5/ar