Micromagnetic and microstructural analyses in chondrules of the Allende meteorite

Results of micromagnetic and microstructural studies of individual chondrules from the Allende carbonaceous meteorite are presented. Allende is a member of the CV3 carbonaceous chondrites, and part of the oxidized meteorites with iron in silicates and oxides. Magnetic hysteresis data in terms of plo...

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Main Authors: Daniel Flores-Gutiérrez, Jaime Urrutia-Fucugauchi, Ligia Pérez-Cruz, Carlos Linares-López
Format: Article
Language:English
Published: Universidad Nacional Autónoma de México 2018-02-01
Series:Revista Mexicana de Ciencias Geológicas
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Online Access:https://rmcg.unam.mx/index.php/rmcg/article/view/731
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author Daniel Flores-Gutiérrez
Jaime Urrutia-Fucugauchi
Ligia Pérez-Cruz
Carlos Linares-López
author_facet Daniel Flores-Gutiérrez
Jaime Urrutia-Fucugauchi
Ligia Pérez-Cruz
Carlos Linares-López
author_sort Daniel Flores-Gutiérrez
collection DOAJ
description Results of micromagnetic and microstructural studies of individual chondrules from the Allende carbonaceous meteorite are presented. Allende is a member of the CV3 carbonaceous chondrites, and part of the oxidized meteorites with iron in silicates and oxides. Magnetic hysteresis data in terms of plots of parameter ratios give relationships with chondrule size and shape, in particular with magnetization ratio (Mr/Ms) and coercivity (Hc). Morphology, internal structure and elemental composition are investigated by scanning electron microscopy and spectrometric analyses. Chondrules show low ranges of magnetization ratios (Mr/Ms from 0 to 0.22) and coercivity (Hc from 3 to 24 mT). Low values suggest that chondrules are susceptible to alteration and re-magnetization, which affects paleointensity determinations for the early planetary magnetic fields A linear relation of Mr/Ms as a function of Hc is found up to values of 0.17 and 17 mT, respectively. This relation correlates with internal microstructure and composition, with compound chondrules showing higher hysteresis ratio and parameter values. Chondrules with hysteresis parameters falling outside the major trend show internal structures, composition and textures indicative of compound chondrules, and fragmentation and alteration processes. Microprobe analyses show distinct mineralogical assemblages with spatial compositional variation related to chondrule size, shape and microstructure.
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spelling doaj-art-1c629f27ee554eb1af35af8d4eae8cb02025-08-20T03:44:54ZengUniversidad Nacional Autónoma de MéxicoRevista Mexicana de Ciencias Geológicas1026-87742007-29022018-02-01271Micromagnetic and microstructural analyses in chondrules of the Allende meteoriteDaniel Flores-Gutiérrez0Jaime Urrutia-Fucugauchi1Ligia Pérez-Cruz2Carlos Linares-López3Instituto de Astronomía, Universidad Nacional Autónoma de México, Cd. Universitaria, Del. Coyoacán, 04510 México D.F., Mexico.Laboratorio de Paleomagnetismo y Geofísica Nuclear, Instituto de Geofísica, Universidad Nacional Autónoma de México, Cd. Universitaria, Del. Coyoacán, 04510 México D.F., Mexico.Laboratorio de Paleomagnetismo y Geofísica Nuclear, Instituto de Geofísica, Universidad Nacional Autónoma de México, Cd. Universitaria, Del. Coyoacán, 04510 México D.F., Mexico.Laboratorio Universitario de Petrología, Instituto de Geofísica. Universidad Nacional Autónoma de México, Cd. Universitaria, Del. Coyoacán, 04510 México D.F., Mexico.Results of micromagnetic and microstructural studies of individual chondrules from the Allende carbonaceous meteorite are presented. Allende is a member of the CV3 carbonaceous chondrites, and part of the oxidized meteorites with iron in silicates and oxides. Magnetic hysteresis data in terms of plots of parameter ratios give relationships with chondrule size and shape, in particular with magnetization ratio (Mr/Ms) and coercivity (Hc). Morphology, internal structure and elemental composition are investigated by scanning electron microscopy and spectrometric analyses. Chondrules show low ranges of magnetization ratios (Mr/Ms from 0 to 0.22) and coercivity (Hc from 3 to 24 mT). Low values suggest that chondrules are susceptible to alteration and re-magnetization, which affects paleointensity determinations for the early planetary magnetic fields A linear relation of Mr/Ms as a function of Hc is found up to values of 0.17 and 17 mT, respectively. This relation correlates with internal microstructure and composition, with compound chondrules showing higher hysteresis ratio and parameter values. Chondrules with hysteresis parameters falling outside the major trend show internal structures, composition and textures indicative of compound chondrules, and fragmentation and alteration processes. Microprobe analyses show distinct mineralogical assemblages with spatial compositional variation related to chondrule size, shape and microstructure. https://rmcg.unam.mx/index.php/rmcg/article/view/731chondrulesmagnetismstructurechemical compositionAllende meteorite
spellingShingle Daniel Flores-Gutiérrez
Jaime Urrutia-Fucugauchi
Ligia Pérez-Cruz
Carlos Linares-López
Micromagnetic and microstructural analyses in chondrules of the Allende meteorite
Revista Mexicana de Ciencias Geológicas
chondrules
magnetism
structure
chemical composition
Allende meteorite
title Micromagnetic and microstructural analyses in chondrules of the Allende meteorite
title_full Micromagnetic and microstructural analyses in chondrules of the Allende meteorite
title_fullStr Micromagnetic and microstructural analyses in chondrules of the Allende meteorite
title_full_unstemmed Micromagnetic and microstructural analyses in chondrules of the Allende meteorite
title_short Micromagnetic and microstructural analyses in chondrules of the Allende meteorite
title_sort micromagnetic and microstructural analyses in chondrules of the allende meteorite
topic chondrules
magnetism
structure
chemical composition
Allende meteorite
url https://rmcg.unam.mx/index.php/rmcg/article/view/731
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