Item type |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
公開日 |
1990-09-01 |
タイトル |
|
|
タイトル |
ISOTOPIC STUDIES OF CARBONATES FROM CIROS-1 DRILLHOLE, WESTERN McMURDO SOUND, ANTARCTICA |
言語 |
|
|
言語 |
eng |
資源タイプ |
|
|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
|
資源タイプ |
departmental bulletin paper |
ID登録 |
|
|
ID登録 |
10.15094/00002629 |
|
ID登録タイプ |
JaLC |
ページ属性 |
|
|
内容記述タイプ |
Other |
|
内容記述 |
P(論文) |
論文名よみ |
|
|
その他のタイトル |
ISOTOPIC STUDIES OF CARBONATES FROM CIROS-1 DRILLHOLE, WESTERN McMURDO SOUND, ANTARCTICA |
著者名よみ |
ワダ, ヒデキ
オカダ, ハクユウ
|
著者名(英) |
WADA, Hideki
OKADA, Hakuyu
|
著者所属(英) |
|
|
|
en |
|
|
Institute of Geosciences, Faculty of Science, Shizuoka University |
著者所属(英) |
|
|
|
en |
|
|
Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University |
抄録(英) |
|
|
内容記述タイプ |
Other |
|
内容記述 |
Carbonates from core samples from the CIROS-1 drillhole, western McMurdo Sound, Antarctica, were analyzed for isotopic, chemical and mineralogical compositions. Carbonates occur as both cement (Mg-calcite and aragonite) and vein filling (aragonite). Samples are generally depleted in ^<18>O to a level that is consistent with pore-water chemistry and downhole temperatures as high as 67℃. However, the samples from the upper part of the hole (<300m sub-bottom depth) contain extremely ^<18>O-depleted aragonite, suggesting precipitation from glacier- or ice-sheet-source meteoric water. Carbon isotopic rations of aragonite are enriched in ^<13>C relative to the neighboring Mg-calcite. Low δ^<13>C values of Mg-calcite may be ascribed to precipitation under the sulfate reduction layer where ^<13>C-depleted carbon dioxide might be released. It is plausible, however, that the high δ^<13>C values of aragonite are due to precipitation under the methane fermentation layer or CO_2 reduction layer, which underlay the sulfate reduction layer and produced ^<13>C-enriched carbon dioxide. Semi-micro scale isotopic analyses along two transects of aragonite veins revealed that δ^<13>C values vary from 3 to 5‰ within a vien. Near the bottom of the drillhole, δ^<18>O values in pore water remained constant during the aragonite precipitation. At shallow depths about 260m below the sea floor, δ^<18>O values in pore water were variable, probably owing to the different contribution of glacier or ice-melt water during the precipitation. |
雑誌書誌ID |
|
|
収録物識別子タイプ |
NCID |
|
収録物識別子 |
AA1072335X |
書誌情報 |
Proceedings of the NIPR Symposium on Antarctic Geosciences
巻 4,
p. 149-164,
発行日 1990-09
|
出版者 |
|
|
出版者 |
National Institute of Polar Research |