Palaeomagnetic data from Late Glacial glaciolacustrine sediments at Rio Corintos, Chubut, Argentina

The characteristics of the Pleistocene glaciations in Patagonia have been partially solved. On the basis of the moraine extent and the varve-counting method, and by analogy with the Weichselian Glaciation in Scandinavia, Caldenius (1932) established a pattern of Patagonian glaciations which has rema...

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Detalles Bibliográficos
Autores principales: Beraza, Luis A., Vilas, Juan Francisco A.
Publicado: 1990
Materias:
glaciolacustrine sediment
late glacial
Late Glacial sediment
moraine
palaeomagnetic data
palaeomagnetism
varve
Argentina, Chubut, Rio Corintos
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00319201_v64_n2-4_p111_Beraza
http://hdl.handle.net/20.500.12110/paper_00319201_v64_n2-4_p111_Beraza
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00319201_v64_n2-4_p111_Beraza
record_format dspace
spelling paper:paper_00319201_v64_n2-4_p111_Beraza2023-06-08T14:58:54Z Palaeomagnetic data from Late Glacial glaciolacustrine sediments at Rio Corintos, Chubut, Argentina Beraza, Luis A. Vilas, Juan Francisco A. glaciolacustrine sediment late glacial Late Glacial sediment moraine palaeomagnetic data palaeomagnetism varve Argentina, Chubut, Rio Corintos The characteristics of the Pleistocene glaciations in Patagonia have been partially solved. On the basis of the moraine extent and the varve-counting method, and by analogy with the Weichselian Glaciation in Scandinavia, Caldenius (1932) established a pattern of Patagonian glaciations which has remained acceptable. Palaeomagnetic studies of glacial sediments have been started with the aim of testing this correlation. A 78-m Late Glacial glaciolacustrine sequence was studied and sampled at Rio Corintos, Chubut Province, Argentina (43 ° 10′ S, 71 ° 15′ W). Approximately 1089 varves were counted; they were thought to have been deposited between 25 000-13 000 years BP. The samples showed strong and stable values of remanent magnetization. Magnetite was identified as the carrier of the remanence. Magnetic susceptibility and intensity were recorded and the expected variations according to grain size were obtained. Recorded declination values oscillated from 30 ° W to 15 ° E, and inclination values from -8 ° to - 56 °. This shift can be attributed to the secular variation of the geomagnetic field. Declination and inclination values were smoothed using a stratigraphic window which covered 40 varves. Assuming that a single varve implies that one year has passed, the secular variation curve can be presented against a scale-time which spans approximately 1200 years. The corresponding VGP path showed 100% clockwise motion in the region of northern Canada. A correlation with other VGPs recorded in Lago Buenos Aires for Late Glacial varves has been established. © 1990. Fil:Beraza, L.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Vilas, J.F.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1990 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00319201_v64_n2-4_p111_Beraza http://hdl.handle.net/20.500.12110/paper_00319201_v64_n2-4_p111_Beraza
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic glaciolacustrine sediment
late glacial
Late Glacial sediment
moraine
palaeomagnetic data
palaeomagnetism
varve
Argentina, Chubut, Rio Corintos
spellingShingle glaciolacustrine sediment
late glacial
Late Glacial sediment
moraine
palaeomagnetic data
palaeomagnetism
varve
Argentina, Chubut, Rio Corintos
Beraza, Luis A.
Vilas, Juan Francisco A.
Palaeomagnetic data from Late Glacial glaciolacustrine sediments at Rio Corintos, Chubut, Argentina
topic_facet glaciolacustrine sediment
late glacial
Late Glacial sediment
moraine
palaeomagnetic data
palaeomagnetism
varve
Argentina, Chubut, Rio Corintos
description The characteristics of the Pleistocene glaciations in Patagonia have been partially solved. On the basis of the moraine extent and the varve-counting method, and by analogy with the Weichselian Glaciation in Scandinavia, Caldenius (1932) established a pattern of Patagonian glaciations which has remained acceptable. Palaeomagnetic studies of glacial sediments have been started with the aim of testing this correlation. A 78-m Late Glacial glaciolacustrine sequence was studied and sampled at Rio Corintos, Chubut Province, Argentina (43 ° 10′ S, 71 ° 15′ W). Approximately 1089 varves were counted; they were thought to have been deposited between 25 000-13 000 years BP. The samples showed strong and stable values of remanent magnetization. Magnetite was identified as the carrier of the remanence. Magnetic susceptibility and intensity were recorded and the expected variations according to grain size were obtained. Recorded declination values oscillated from 30 ° W to 15 ° E, and inclination values from -8 ° to - 56 °. This shift can be attributed to the secular variation of the geomagnetic field. Declination and inclination values were smoothed using a stratigraphic window which covered 40 varves. Assuming that a single varve implies that one year has passed, the secular variation curve can be presented against a scale-time which spans approximately 1200 years. The corresponding VGP path showed 100% clockwise motion in the region of northern Canada. A correlation with other VGPs recorded in Lago Buenos Aires for Late Glacial varves has been established. © 1990.
author Beraza, Luis A.
Vilas, Juan Francisco A.
author_facet Beraza, Luis A.
Vilas, Juan Francisco A.
author_sort Beraza, Luis A.
title Palaeomagnetic data from Late Glacial glaciolacustrine sediments at Rio Corintos, Chubut, Argentina
title_short Palaeomagnetic data from Late Glacial glaciolacustrine sediments at Rio Corintos, Chubut, Argentina
title_full Palaeomagnetic data from Late Glacial glaciolacustrine sediments at Rio Corintos, Chubut, Argentina
title_fullStr Palaeomagnetic data from Late Glacial glaciolacustrine sediments at Rio Corintos, Chubut, Argentina
title_full_unstemmed Palaeomagnetic data from Late Glacial glaciolacustrine sediments at Rio Corintos, Chubut, Argentina
title_sort palaeomagnetic data from late glacial glaciolacustrine sediments at rio corintos, chubut, argentina
publishDate 1990
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00319201_v64_n2-4_p111_Beraza
http://hdl.handle.net/20.500.12110/paper_00319201_v64_n2-4_p111_Beraza
work_keys_str_mv AT berazaluisa palaeomagneticdatafromlateglacialglaciolacustrinesedimentsatriocorintoschubutargentina
AT vilasjuanfranciscoa palaeomagneticdatafromlateglacialglaciolacustrinesedimentsatriocorintoschubutargentina
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