METEORIC WATER INFILTRATION IN SKALLEN MARBLES, EAST ANTARCTICA : OXYGEN ISOTOPIC EVIDENCE
We report here extremely large millimeter scale oxygen isotopic heterogeneity in calcites from a Skallen marble specimen. The δ^<18>O of calcite cores and most of the calcite grain boundaries are grouped around 17‰ while two analyses from the calcite-phlogopite grain boundary show depletion to...
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Department of Geosciences, Osaka City University
1997
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ftnipr:oai:nipr.repo.nii.ac.jp:00002848 2023-05-15T13:49:00+02:00 METEORIC WATER INFILTRATION IN SKALLEN MARBLES, EAST ANTARCTICA : OXYGEN ISOTOPIC EVIDENCE / ワダ ヒデキ M. SATISH-KUMAR Hideki WADA 1997-09 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2848 http://id.nii.ac.jp/1291/00002848/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2848&item_no=1&attribute_id=18&file_no=1 en eng Department of Geosciences, Osaka City University Department of Biology and Geosciences, Shizuoka University National Institute of Polar Research https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2848 http://id.nii.ac.jp/1291/00002848/ AA1072335X Proceedings of the NIPR Symposium on Antarctic Geosciences, 10, 111-119(1997-09) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2848&item_no=1&attribute_id=18&file_no=1 Skallen marbles oxygen isotopes calcite meteoric water fluid infiltration Departmental Bulletin Paper P(論文) 1997 ftnipr 2022-11-26T19:42:17Z We report here extremely large millimeter scale oxygen isotopic heterogeneity in calcites from a Skallen marble specimen. The δ^<18>O of calcite cores and most of the calcite grain boundaries are grouped around 17‰ while two analyses from the calcite-phlogopite grain boundary show depletion to -1‰. A corresponding δ^<13>C enrichment (only 0.7‰) is also observed. The δ^<13>C of graphite does not show any heterogeneity. The homogeneity of δ^<18>O and δ^<13>C of calcite (except for the local depletion) and δ^<13>C of graphite indicate that the marbles evolved through prograde and peak metamorphism with possible internal fluid buffering. The variations observed in carbon and oxygen isotopes can be ascribed to devolatilization reactions. The peak metamorphic temperature estimate by carbon isotope thermometry gave 760℃, consistent with regional peak metamorphic conditions. The local occurrence of isotopic heterogeneity on the calcite-phlogopite boundary suggests that there was meteoric water infiltration during the late stages of metamorphic history. Millimeter scale gigantic oxygen isotopic heterogeneity is observed for the first time in metamorphic rocks. The mechanism of isotope exchange invloved is unclear in the present study, but may indicate a process of fluid flow through preferential grain boundaries and by solution-reprecipitation or diffusion. Report Antarc* Antarctica East Antarctica National Institute of Polar Research Repository, Japan East Antarctica Skallen ENVELOPE(39.467,39.467,-69.650,-69.650) |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
topic |
Skallen marbles oxygen isotopes calcite meteoric water fluid infiltration |
spellingShingle |
Skallen marbles oxygen isotopes calcite meteoric water fluid infiltration / ワダ ヒデキ M. SATISH-KUMAR Hideki WADA METEORIC WATER INFILTRATION IN SKALLEN MARBLES, EAST ANTARCTICA : OXYGEN ISOTOPIC EVIDENCE |
topic_facet |
Skallen marbles oxygen isotopes calcite meteoric water fluid infiltration |
description |
We report here extremely large millimeter scale oxygen isotopic heterogeneity in calcites from a Skallen marble specimen. The δ^<18>O of calcite cores and most of the calcite grain boundaries are grouped around 17‰ while two analyses from the calcite-phlogopite grain boundary show depletion to -1‰. A corresponding δ^<13>C enrichment (only 0.7‰) is also observed. The δ^<13>C of graphite does not show any heterogeneity. The homogeneity of δ^<18>O and δ^<13>C of calcite (except for the local depletion) and δ^<13>C of graphite indicate that the marbles evolved through prograde and peak metamorphism with possible internal fluid buffering. The variations observed in carbon and oxygen isotopes can be ascribed to devolatilization reactions. The peak metamorphic temperature estimate by carbon isotope thermometry gave 760℃, consistent with regional peak metamorphic conditions. The local occurrence of isotopic heterogeneity on the calcite-phlogopite boundary suggests that there was meteoric water infiltration during the late stages of metamorphic history. Millimeter scale gigantic oxygen isotopic heterogeneity is observed for the first time in metamorphic rocks. The mechanism of isotope exchange invloved is unclear in the present study, but may indicate a process of fluid flow through preferential grain boundaries and by solution-reprecipitation or diffusion. |
format |
Report |
author |
/ ワダ ヒデキ M. SATISH-KUMAR Hideki WADA |
author_facet |
/ ワダ ヒデキ M. SATISH-KUMAR Hideki WADA |
author_sort |
/ ワダ ヒデキ |
title |
METEORIC WATER INFILTRATION IN SKALLEN MARBLES, EAST ANTARCTICA : OXYGEN ISOTOPIC EVIDENCE |
title_short |
METEORIC WATER INFILTRATION IN SKALLEN MARBLES, EAST ANTARCTICA : OXYGEN ISOTOPIC EVIDENCE |
title_full |
METEORIC WATER INFILTRATION IN SKALLEN MARBLES, EAST ANTARCTICA : OXYGEN ISOTOPIC EVIDENCE |
title_fullStr |
METEORIC WATER INFILTRATION IN SKALLEN MARBLES, EAST ANTARCTICA : OXYGEN ISOTOPIC EVIDENCE |
title_full_unstemmed |
METEORIC WATER INFILTRATION IN SKALLEN MARBLES, EAST ANTARCTICA : OXYGEN ISOTOPIC EVIDENCE |
title_sort |
meteoric water infiltration in skallen marbles, east antarctica : oxygen isotopic evidence |
publisher |
Department of Geosciences, Osaka City University |
publishDate |
1997 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2848 http://id.nii.ac.jp/1291/00002848/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2848&item_no=1&attribute_id=18&file_no=1 |
long_lat |
ENVELOPE(39.467,39.467,-69.650,-69.650) |
geographic |
East Antarctica Skallen |
geographic_facet |
East Antarctica Skallen |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2848 http://id.nii.ac.jp/1291/00002848/ AA1072335X Proceedings of the NIPR Symposium on Antarctic Geosciences, 10, 111-119(1997-09) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2848&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766250321112203264 |