Short note on ultramafic granulites in the Ongul Islands area, East Antarctica
Ultramafic granulites in the East and West Ongul Islands area are grouped into two types, A and B. One of the fundamental criteria of the grouping is that type A does not yield plagioclase and type B does. Type A is characterized by the abundance of orthopyroxene and clinopyroxene and by the lack of...
Main Author: | |
---|---|
Format: | Report |
Language: | English |
Published: |
Institute of Geology and Mineralogy, Faculty of Science, Hiroshima University
1986
|
Subjects: | |
Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2015 http://id.nii.ac.jp/1291/00002015/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2015&item_no=1&attribute_id=18&file_no=1 |
id |
ftnipr:oai:nipr.repo.nii.ac.jp:00002015 |
---|---|
record_format |
openpolar |
spelling |
ftnipr:oai:nipr.repo.nii.ac.jp:00002015 2023-05-15T13:47:59+02:00 Short note on ultramafic granulites in the Ongul Islands area, East Antarctica Morihisa Suzuki 1986-09 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2015 http://id.nii.ac.jp/1291/00002015/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2015&item_no=1&attribute_id=18&file_no=1 en eng Institute of Geology and Mineralogy, Faculty of Science, Hiroshima University https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2015 http://id.nii.ac.jp/1291/00002015/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 43, 85-100(1986-09) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2015&item_no=1&attribute_id=18&file_no=1 Departmental Bulletin Paper P(論文) 1986 ftnipr 2022-11-12T19:42:52Z Ultramafic granulites in the East and West Ongul Islands area are grouped into two types, A and B. One of the fundamental criteria of the grouping is that type A does not yield plagioclase and type B does. Type A is characterized by the abundance of orthopyroxene and clinopyroxene and by the lack of plagioclase and garnet. It occasionally yields olivine. Type B is characterized by the presence of plagioclase and/or garnet and by the poverty in pyroxenes. In common cases, type A tends to occur as massive isolated blocks or pods in the surrounding gneisses, while type B as concordant sheets or layers showing a distinctly foliated structure. Between these two types, chemical characteristics of main constituent minerals such as orthopyroxene, clinopyroxene and hornblende are different from each other. Those in type A are comparatively more magnesian and less aluminous. Metamorphic temperature estimated from the pairs of orthopyroxene and clinopyroxene of both types is as high as around 800℃. Pressure condition is calculated based upon the associations of garnet, pyroxenes and plagioclase of type B to give the values around 7.5kb. The essential difference between the two types is inferred to reflect the difference in petrological characters of original rocks. Report Antarc* Antarctica East Antarctica Memoirs of National Institute of Polar Research Polar Research National Institute of Polar Research Repository, Japan East Antarctica Ongul ENVELOPE(39.533,39.533,-69.017,-69.017) |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
description |
Ultramafic granulites in the East and West Ongul Islands area are grouped into two types, A and B. One of the fundamental criteria of the grouping is that type A does not yield plagioclase and type B does. Type A is characterized by the abundance of orthopyroxene and clinopyroxene and by the lack of plagioclase and garnet. It occasionally yields olivine. Type B is characterized by the presence of plagioclase and/or garnet and by the poverty in pyroxenes. In common cases, type A tends to occur as massive isolated blocks or pods in the surrounding gneisses, while type B as concordant sheets or layers showing a distinctly foliated structure. Between these two types, chemical characteristics of main constituent minerals such as orthopyroxene, clinopyroxene and hornblende are different from each other. Those in type A are comparatively more magnesian and less aluminous. Metamorphic temperature estimated from the pairs of orthopyroxene and clinopyroxene of both types is as high as around 800℃. Pressure condition is calculated based upon the associations of garnet, pyroxenes and plagioclase of type B to give the values around 7.5kb. The essential difference between the two types is inferred to reflect the difference in petrological characters of original rocks. |
format |
Report |
author |
Morihisa Suzuki |
spellingShingle |
Morihisa Suzuki Short note on ultramafic granulites in the Ongul Islands area, East Antarctica |
author_facet |
Morihisa Suzuki |
author_sort |
Morihisa Suzuki |
title |
Short note on ultramafic granulites in the Ongul Islands area, East Antarctica |
title_short |
Short note on ultramafic granulites in the Ongul Islands area, East Antarctica |
title_full |
Short note on ultramafic granulites in the Ongul Islands area, East Antarctica |
title_fullStr |
Short note on ultramafic granulites in the Ongul Islands area, East Antarctica |
title_full_unstemmed |
Short note on ultramafic granulites in the Ongul Islands area, East Antarctica |
title_sort |
short note on ultramafic granulites in the ongul islands area, east antarctica |
publisher |
Institute of Geology and Mineralogy, Faculty of Science, Hiroshima University |
publishDate |
1986 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2015 http://id.nii.ac.jp/1291/00002015/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2015&item_no=1&attribute_id=18&file_no=1 |
long_lat |
ENVELOPE(39.533,39.533,-69.017,-69.017) |
geographic |
East Antarctica Ongul |
geographic_facet |
East Antarctica Ongul |
genre |
Antarc* Antarctica East Antarctica Memoirs of National Institute of Polar Research Polar Research |
genre_facet |
Antarc* Antarctica East Antarctica Memoirs of National Institute of Polar Research Polar Research |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2015 http://id.nii.ac.jp/1291/00002015/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 43, 85-100(1986-09) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2015&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766248336022568960 |