| Item type |
デフォルトアイテムタイプ_（フル）(1) |
| 公開日 |
2023-03-18 |
| タイトル |
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タイトル |
Formation of an ultracarbonaceous Antarctic micrometeorite through minimal aqueous alteration in a small porous icy body |
|
言語 |
en |
| タイトル |
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|
タイトル |
Formation of an Ultracarbonaceous Antarctic Micrometeorite through Minimum Aqueous Alteration in a Small Porous Icy Body |
|
言語 |
ja |
| 作成者 |
Yabuta, Hikaru
Noguchi, Takaaki
Itoh, Shoichi
Nakamura, Tomoki
Miyake, Akira
Shinichi, Tsujimoto
Ohashi, Noriaki
Sakamoto, Naoya
Hashiguchi, Minako
Abe, Ken-ichi
Okubo, Aya
Kilcoyne, A. L. David
Tachibana, Shogo
Okazaki, Ryuji
Terada, Kentaro
Ebihara, Mitsuru
Nagahara, Hiroko
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| アクセス権 |
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アクセス権 |
open access |
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アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
| 権利情報 |
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権利情報 |
© 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ |
| 権利情報 |
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|
権利情報 |
This is not the published version. Please cite only the published version. この論文は出版社版でありません。引用の際には出版社版をご確認、ご利用ください。 |
| 主題 |
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主題Scheme |
Other |
|
主題 |
Ultracarbonaceous Antarctic micrometeorites |
| 主題 |
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主題Scheme |
Other |
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主題 |
Organic matter |
| 主題 |
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主題Scheme |
Other |
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主題 |
GEMS |
| 主題 |
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主題Scheme |
Other |
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主題 |
Aqueous alteration |
| 主題 |
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主題Scheme |
Other |
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主題 |
Comet |
| 主題 |
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主題Scheme |
Other |
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主題 |
Shock |
| 主題 |
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主題Scheme |
Other |
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主題 |
SIMS |
| 主題 |
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主題Scheme |
Other |
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主題 |
XANES |
| 主題 |
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主題Scheme |
Other |
|
主題 |
TEM |
| 内容記述 |
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内容記述 |
A comprehensive study of the organic chemistry and mineralogy of an ultracarbonaceous micrometeorite (UCAMM D05IB80) collected from near the Dome Fuji Station, Antarctica, was carried out to understand the genetic relationship among organic materials, silicates, and water. The micrometeorite is composed of a dense aggregate of ∼5 µm-sized hollow ellipsoidal organic material containing submicrometer-sized phases such as glass with embedded metal and sulfides (GEMS) and mineral grains. There is a wide area of organic material (∼15 × 15 μm) in its interior. Low-Ca pyroxene is much more abundant than olivine and shows various Mg/(Mg + Fe) ratios ranging from ∼1.0 to 0.78, which is common to previous works on UCAMMs. By contrast, GEMS grains in this UCAMM have unusual chemical compositions. They are depleted in both Mg and S, which suggests that these elements were leached out from the GEMS grains during very weak aqueous alteration, without the formation of phyllosilicates. The organic materials have two textures—smooth and globular with an irregular outline—and these are composed of imine, nitrile and/or aromatic nitrogen heterocycles, and amide. The ratio of nitrogen to carbon (N/C) in the smooth region of the organics is ∼0.15, which is five times higher than that of insoluble organic macromolecules in types 1 and 2 carbonaceous chondritic meteorites. In addition, the UCAMM organic materials are soluble in epoxy and are thus hydrophilic; this polar nature indicates that they are very primitive. The surface of the material is coated with an inorganic layer, a few nanometers thick, that consists of C, O, Si, S, and Fe. Sulfur is also contained in the interior, implying the presence of organosulfur moieties. There are no isotopic anomalies of D, 13C, or 15N in the organic material. Interstellar photochemistry alone would not be sufficient to explain the N/C ratio of the UCAMM organics; therefore, we suggest that a very small amount of fluid on a comet must have been necessary for the formation of the UCAMM. The GEMS grains depleted in Mg and S in the UCAMM prove a very weak degree of aqueous alteration; weaker than that of carbonaceous chondrites. Short-duration weak alteration probably caused by planetesimal shock locally melted cometary ice grains and released water that dissolved the organics; the fluid would likely have not mobilized because of the very low thermal conductivity of the porous icy body. This event allowed the formation of the large organic puddle of the UCAMM, as well as organic matter sulfurization, formation of thin membrane-like layers of minerals, and deformation of organic nanoglobules. |
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言語 |
en |
| 内容記述 |
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内容記述タイプ |
Other |
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内容記述 |
アクセプト後にタイトル・アブストラクト等変更あり、著者最終稿は変更前のタイトル"Formation of an Ultracarbonaceous Antarctic Micrometeorite through Minimum Aqueous Alteration in a Small Porous Icy Body" |
| 内容記述 |
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内容記述タイプ |
Other |
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内容記述 |
This work was supported by a Grant-in-Aid for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology (No. 22224010, PI: H. Nagahara). The STXM facility at the beamline 5.3.2.2, ALS, is supported by the Department of Energy, Basic Energy Sciences Program. |
| 出版者 |
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出版者 |
Elsevier |
| 言語 |
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言語 |
eng |
| 資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
journal article |
| 出版タイプ |
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出版タイプ |
AO |
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出版タイプResource |
http://purl.org/coar/version/c_b1a7d7d4d402bcce |
| 関連情報 |
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識別子タイプ |
DOI |
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関連識別子 |
10.1016/j.gca.2017.06.047 |
| 関連情報 |
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識別子タイプ |
DOI |
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関連識別子 |
https://doi.org/10.1016/j.gca.2017.06.047 |
| 収録物識別子 |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
0016-7037 |
| 開始ページ |
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開始ページ |
172 |
| 書誌情報 |
Geochimica et Cosmochimica Acta
Geochimica et Cosmochimica Acta
巻 214,
p. 172-190,
発行日 2017-10-01
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| 旧ID |
48703 |
GeochimCosmochimActa_214_172.pdf (12.3 MB)
