Rock magnetism in late Cenozoic sediments at San Antonio de Areco, Buenos Aires province

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A geological and geophysical study in fluvial post-pampean sediments cropping out on the right bank of the Rio Areco was carried out. The sequence studied comprises the Guerrero and Río Salado members of the Luján Formation, in which three palaeosols are developed. The geophysical studies suggest an...

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Autores principales: Walther, A.M., Orgeira, M.J., Lippai, H.F.
Formato: JOUR
Materias:
Environmental magnetism
Paleoclimate
Quaternary
Stratigraphy
detrital deposit
magnetite
paleoclimate
paleosol
proxy climate record
titanomagnetite
Argentina
Buenos Aires [Argentina]
South America
Western Hemisphere
World
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00044822_v59_n3_p433_Walther
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_00044822_v59_n3_p433_Walther
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spelling todo:paper_00044822_v59_n3_p433_Walther2023-10-03T13:57:57Z Rock magnetism in late Cenozoic sediments at San Antonio de Areco, Buenos Aires province Walther, A.M. Orgeira, M.J. Lippai, H.F. Environmental magnetism Paleoclimate Quaternary Stratigraphy detrital deposit magnetite paleoclimate paleosol proxy climate record Quaternary titanomagnetite Argentina Buenos Aires [Argentina] South America Western Hemisphere World A geological and geophysical study in fluvial post-pampean sediments cropping out on the right bank of the Rio Areco was carried out. The sequence studied comprises the Guerrero and Río Salado members of the Luján Formation, in which three palaeosols are developed. The geophysical studies suggest an impoverishment of the detrital ferrimagnetic minerals (magnetite and titanomagnetite) in the parent material, due to the action of pedogenic processes, accompanied by the generation of two neominerales, one antiferromagnetic and the other ferrimagnetic. The ferrimagnetic mineral consists of particles of ultrafine magnetite (state of superparamagnetic domain, grain size approaching 0.01 μm) formed during periods of excess water. The antiferromagnetic minerals (hematite and/or goethite) were generated in periods of major water deficiency. The presence of these minerals would be indicating a warm and humid climate with a marked dryperiod. The oldest paleosol was developed on the Guerrero Member which correlates with the Puesto Callejón Viejo palaeosol that has an age between 10,000 and 8,000 years AP, in this profile. The Rio Salado Member and the two paleosols developed on it would have developed during the warm period known as, Megathermal, between 9,000 and 7,000 years BP. © 2004 Asociación Geológica Argentina. Fil:Walther, A.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Orgeira, M.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Lippai, H.F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00044822_v59_n3_p433_Walther
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Environmental magnetism
Paleoclimate
Quaternary
Stratigraphy
detrital deposit
magnetite
paleoclimate
paleosol
proxy climate record
Quaternary
titanomagnetite
Argentina
Buenos Aires [Argentina]
South America
Western Hemisphere
World
spellingShingle Environmental magnetism
Paleoclimate
Quaternary
Stratigraphy
detrital deposit
magnetite
paleoclimate
paleosol
proxy climate record
Quaternary
titanomagnetite
Argentina
Buenos Aires [Argentina]
South America
Western Hemisphere
World
Walther, A.M.
Orgeira, M.J.
Lippai, H.F.
Rock magnetism in late Cenozoic sediments at San Antonio de Areco, Buenos Aires province
topic_facet Environmental magnetism
Paleoclimate
Quaternary
Stratigraphy
detrital deposit
magnetite
paleoclimate
paleosol
proxy climate record
Quaternary
titanomagnetite
Argentina
Buenos Aires [Argentina]
South America
Western Hemisphere
World
description A geological and geophysical study in fluvial post-pampean sediments cropping out on the right bank of the Rio Areco was carried out. The sequence studied comprises the Guerrero and Río Salado members of the Luján Formation, in which three palaeosols are developed. The geophysical studies suggest an impoverishment of the detrital ferrimagnetic minerals (magnetite and titanomagnetite) in the parent material, due to the action of pedogenic processes, accompanied by the generation of two neominerales, one antiferromagnetic and the other ferrimagnetic. The ferrimagnetic mineral consists of particles of ultrafine magnetite (state of superparamagnetic domain, grain size approaching 0.01 μm) formed during periods of excess water. The antiferromagnetic minerals (hematite and/or goethite) were generated in periods of major water deficiency. The presence of these minerals would be indicating a warm and humid climate with a marked dryperiod. The oldest paleosol was developed on the Guerrero Member which correlates with the Puesto Callejón Viejo palaeosol that has an age between 10,000 and 8,000 years AP, in this profile. The Rio Salado Member and the two paleosols developed on it would have developed during the warm period known as, Megathermal, between 9,000 and 7,000 years BP. © 2004 Asociación Geológica Argentina.
format JOUR
author Walther, A.M.
Orgeira, M.J.
Lippai, H.F.
author_facet Walther, A.M.
Orgeira, M.J.
Lippai, H.F.
author_sort Walther, A.M.
title Rock magnetism in late Cenozoic sediments at San Antonio de Areco, Buenos Aires province
title_short Rock magnetism in late Cenozoic sediments at San Antonio de Areco, Buenos Aires province
title_full Rock magnetism in late Cenozoic sediments at San Antonio de Areco, Buenos Aires province
title_fullStr Rock magnetism in late Cenozoic sediments at San Antonio de Areco, Buenos Aires province
title_full_unstemmed Rock magnetism in late Cenozoic sediments at San Antonio de Areco, Buenos Aires province
title_sort rock magnetism in late cenozoic sediments at san antonio de areco, buenos aires province
url http://hdl.handle.net/20.500.12110/paper_00044822_v59_n3_p433_Walther
work_keys_str_mv AT waltheram rockmagnetisminlatecenozoicsedimentsatsanantoniodearecobuenosairesprovince
AT orgeiramj rockmagnetisminlatecenozoicsedimentsatsanantoniodearecobuenosairesprovince
AT lippaihf rockmagnetisminlatecenozoicsedimentsatsanantoniodearecobuenosairesprovince
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