Early cretaceous absolute geomagnetic paleointensities from Cordoba Province (Argentina)
We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks of Sierra Chica de Cordoba (Argentina). The new K-Ar isotopic ages of 5 samples range from 136 to 122 Ma. Twenty five samples from 7 individual flows yielded acceptable paleointensity estimates. The mea...
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13438832_v58_n10_p1333_Ruiz http://hdl.handle.net/20.500.12110/paper_13438832_v58_n10_p1333_Ruiz |
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paper:paper_13438832_v58_n10_p1333_Ruiz2023-06-08T16:10:43Z Early cretaceous absolute geomagnetic paleointensities from Cordoba Province (Argentina) Geuna, Silvana Evangelina Early Cretaceous Paleointensity rock-magnetism South America Cretaceous geochronology geomagnetism magnetic intensity paleomagnetism rock property volcanic rock Argentina Cordoba [Argentina] South America We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks of Sierra Chica de Cordoba (Argentina). The new K-Ar isotopic ages of 5 samples range from 136 to 122 Ma. Twenty five samples from 7 individual flows yielded acceptable paleointensity estimates. The mean paleointensity values per flow are ranging from 53.0±1.9 to 25.4±2.6 μT and the corresponding Virtual Dipole Moments (VDMs) are ranging from 9.3±1.3 to 4.6±0.5 (1022 Am2). This corresponds to the mean value of 7.3±1.7x1022 Am2, which is compatible to the present geomagnetic axial dipole. Currently available selected paleointensity data from 80 to 130 Ma suggest that geomagnetic field strength frequently fluctuated before and during the Cretaceous Normal Superchron while the magnetic polarity maintained stable. The mean paleointensities derived from Cordoba lavas agree remarkably well with those obtained from the Parana Magmatic Province (133-132 Ma). This reinforces the hypothesis about the unreliability of ‘Mesozoic Dipole Low'. © 2006, The Seismological Society of Japan, Society of Geomagnetism and Earth, Planetary and Space Sciences, The Volcanological Society of Japan, The Geodetic Society of Japan, The Japanese Society for Planetary Sciences. All rights reserved. Fil:Geuna, S.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2006 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13438832_v58_n10_p1333_Ruiz http://hdl.handle.net/20.500.12110/paper_13438832_v58_n10_p1333_Ruiz |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Early Cretaceous Paleointensity rock-magnetism South America Cretaceous geochronology geomagnetism magnetic intensity paleomagnetism rock property volcanic rock Argentina Cordoba [Argentina] South America |
spellingShingle |
Early Cretaceous Paleointensity rock-magnetism South America Cretaceous geochronology geomagnetism magnetic intensity paleomagnetism rock property volcanic rock Argentina Cordoba [Argentina] South America Geuna, Silvana Evangelina Early cretaceous absolute geomagnetic paleointensities from Cordoba Province (Argentina) |
topic_facet |
Early Cretaceous Paleointensity rock-magnetism South America Cretaceous geochronology geomagnetism magnetic intensity paleomagnetism rock property volcanic rock Argentina Cordoba [Argentina] South America |
description |
We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks of Sierra Chica de Cordoba (Argentina). The new K-Ar isotopic ages of 5 samples range from 136 to 122 Ma. Twenty five samples from 7 individual flows yielded acceptable paleointensity estimates. The mean paleointensity values per flow are ranging from 53.0±1.9 to 25.4±2.6 μT and the corresponding Virtual Dipole Moments (VDMs) are ranging from 9.3±1.3 to 4.6±0.5 (1022 Am2). This corresponds to the mean value of 7.3±1.7x1022 Am2, which is compatible to the present geomagnetic axial dipole. Currently available selected paleointensity data from 80 to 130 Ma suggest that geomagnetic field strength frequently fluctuated before and during the Cretaceous Normal Superchron while the magnetic polarity maintained stable. The mean paleointensities derived from Cordoba lavas agree remarkably well with those obtained from the Parana Magmatic Province (133-132 Ma). This reinforces the hypothesis about the unreliability of ‘Mesozoic Dipole Low'. © 2006, The Seismological Society of Japan, Society of Geomagnetism and Earth, Planetary and Space Sciences, The Volcanological Society of Japan, The Geodetic Society of Japan, The Japanese Society for Planetary Sciences. All rights reserved. |
author |
Geuna, Silvana Evangelina |
author_facet |
Geuna, Silvana Evangelina |
author_sort |
Geuna, Silvana Evangelina |
title |
Early cretaceous absolute geomagnetic paleointensities from Cordoba Province (Argentina) |
title_short |
Early cretaceous absolute geomagnetic paleointensities from Cordoba Province (Argentina) |
title_full |
Early cretaceous absolute geomagnetic paleointensities from Cordoba Province (Argentina) |
title_fullStr |
Early cretaceous absolute geomagnetic paleointensities from Cordoba Province (Argentina) |
title_full_unstemmed |
Early cretaceous absolute geomagnetic paleointensities from Cordoba Province (Argentina) |
title_sort |
early cretaceous absolute geomagnetic paleointensities from cordoba province (argentina) |
publishDate |
2006 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13438832_v58_n10_p1333_Ruiz http://hdl.handle.net/20.500.12110/paper_13438832_v58_n10_p1333_Ruiz |
work_keys_str_mv |
AT geunasilvanaevangelina earlycretaceousabsolutegeomagneticpaleointensitiesfromcordobaprovinceargentina |
_version_ |
1768542609978949632 |