Computer simulation of anomalous composition of Mg-Fe plagioclase in meteorite

The chemical anomalies of meteoritic plagioclase which appear also in lunar plagioclase, result in the difference between An=100・Ca/(K+Na+Ca) and An(Al, Si)=(300・(Al/Si)-100)/(1+Al/Si) caused by the various types of substitution which are dealt with computer simulation. Almost all average data are p...

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Main Author: Yasunori Miura
Format: Report
Language:English
Published: Department of Mineralogical Science and Geology, Faculty of Science, Yamaguchi University 1984
Subjects:
Online Access:https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1726
http://id.nii.ac.jp/1291/00001726/
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spelling ftnipr:oai:nipr.repo.nii.ac.jp:00001726 2023-05-15T17:10:59+02:00 Computer simulation of anomalous composition of Mg-Fe plagioclase in meteorite Yasunori Miura 1984-12 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1726 http://id.nii.ac.jp/1291/00001726/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1726&item_no=1&attribute_id=18&file_no=1 en eng Department of Mineralogical Science and Geology, Faculty of Science, Yamaguchi University https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1726 http://id.nii.ac.jp/1291/00001726/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 35, 226-242(1984-12) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1726&item_no=1&attribute_id=18&file_no=1 Departmental Bulletin Paper P(論文) 1984 ftnipr 2022-11-12T19:42:34Z The chemical anomalies of meteoritic plagioclase which appear also in lunar plagioclase, result in the difference between An=100・Ca/(K+Na+Ca) and An(Al, Si)=(300・(Al/Si)-100)/(1+Al/Si) caused by the various types of substitution which are dealt with computer simulation. Almost all average data are plotted close to the substitution vectors of Fe and Mg cations into T or M sites. Fe-Mg plagioclases are crystallized as Mg-rich plagioclases (An_<67-91>) in C3 or CV3 chondrites, whereas Fe-rich plagioclases (An_<1-14>) are predominantly crystallized in H6,L6 or LL6 chondrites. The maximum contents of Mg and Fe are 0.343 (per formula unit in O=8) in Allende (CV3) and 0.126 in Plainview (H5) chondrites, respectively, though maskelynite has much more Mg and Fe contents with excess total cations. Chemical heterogeneity of plagioclase in eight chondrites and Juvinas eucrite can be shown by the number of regions in An-content vs. Fe/(Fe+Mg) diagram; that is, three distinct regions of Willard (L6), ALH-769,75 (L6) and Plainview (H5); two regions of Holbrook (L6), Y-74640,81 (H6), Allende (CV3) and ALH-77307,85 (C3); and single region of Y-75258,97 (LL6). Wide variation of Fe/(Fe+Mg) in Juvinas with much more Fe- and Mg-substitutions indicates a mixture of various parent materials. The different values of Fe/(Fe+Mg) between chondrule and matrix with a nearly constant An-content in the Y-75135,93 (L5 (67%)) chondrite suggest that chemical heterogeneity of plagioclase might have occurred in the formation of the chondrite. Report Memoirs of National Institute of Polar Research Polar Research National Institute of Polar Research Repository, Japan The ''Y'' ENVELOPE(-112.453,-112.453,57.591,57.591)
institution Open Polar
collection National Institute of Polar Research Repository, Japan
op_collection_id ftnipr
language English
description The chemical anomalies of meteoritic plagioclase which appear also in lunar plagioclase, result in the difference between An=100・Ca/(K+Na+Ca) and An(Al, Si)=(300・(Al/Si)-100)/(1+Al/Si) caused by the various types of substitution which are dealt with computer simulation. Almost all average data are plotted close to the substitution vectors of Fe and Mg cations into T or M sites. Fe-Mg plagioclases are crystallized as Mg-rich plagioclases (An_<67-91>) in C3 or CV3 chondrites, whereas Fe-rich plagioclases (An_<1-14>) are predominantly crystallized in H6,L6 or LL6 chondrites. The maximum contents of Mg and Fe are 0.343 (per formula unit in O=8) in Allende (CV3) and 0.126 in Plainview (H5) chondrites, respectively, though maskelynite has much more Mg and Fe contents with excess total cations. Chemical heterogeneity of plagioclase in eight chondrites and Juvinas eucrite can be shown by the number of regions in An-content vs. Fe/(Fe+Mg) diagram; that is, three distinct regions of Willard (L6), ALH-769,75 (L6) and Plainview (H5); two regions of Holbrook (L6), Y-74640,81 (H6), Allende (CV3) and ALH-77307,85 (C3); and single region of Y-75258,97 (LL6). Wide variation of Fe/(Fe+Mg) in Juvinas with much more Fe- and Mg-substitutions indicates a mixture of various parent materials. The different values of Fe/(Fe+Mg) between chondrule and matrix with a nearly constant An-content in the Y-75135,93 (L5 (67%)) chondrite suggest that chemical heterogeneity of plagioclase might have occurred in the formation of the chondrite.
format Report
author Yasunori Miura
spellingShingle Yasunori Miura
Computer simulation of anomalous composition of Mg-Fe plagioclase in meteorite
author_facet Yasunori Miura
author_sort Yasunori Miura
title Computer simulation of anomalous composition of Mg-Fe plagioclase in meteorite
title_short Computer simulation of anomalous composition of Mg-Fe plagioclase in meteorite
title_full Computer simulation of anomalous composition of Mg-Fe plagioclase in meteorite
title_fullStr Computer simulation of anomalous composition of Mg-Fe plagioclase in meteorite
title_full_unstemmed Computer simulation of anomalous composition of Mg-Fe plagioclase in meteorite
title_sort computer simulation of anomalous composition of mg-fe plagioclase in meteorite
publisher Department of Mineralogical Science and Geology, Faculty of Science, Yamaguchi University
publishDate 1984
url https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1726
http://id.nii.ac.jp/1291/00001726/
https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1726&item_no=1&attribute_id=18&file_no=1
long_lat ENVELOPE(-112.453,-112.453,57.591,57.591)
geographic The ''Y''
geographic_facet The ''Y''
genre Memoirs of National Institute of Polar Research
Polar Research
genre_facet Memoirs of National Institute of Polar Research
Polar Research
op_relation https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1726
http://id.nii.ac.jp/1291/00001726/
AA00733561
Memoirs of National Institute of Polar Research. Special issue, 35, 226-242(1984-12)
https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1726&item_no=1&attribute_id=18&file_no=1
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