| Item type |
学術雑誌論文 / Journal Article(1) |
| 公開日 |
2022-10-27 |
| タイトル |
|
|
タイトル |
Genesis of magmatic ilmenite ores associated with the Mazua ultramafic intrusion, NE Mozambique |
|
言語 |
en |
| 言語 |
|
|
言語 |
eng |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Fe-Ti oxides |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Ilmenite |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Ultramafic intrusions |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Mazua |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Mozambique |
| 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 |
journal article |
| アクセス権 |
|
|
アクセス権 |
open access |
|
アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
| 作成者 |
Unganai, David A.B.
Imai, Akira
Takahashi, Ryohei
Jamalc, Daud L.
Agangi, Andrea
Hoshide, Takashi
Sato, Hinako
|
| 内容記述 |
|
|
内容記述タイプ |
Abstract |
|
内容記述 |
The Mazua ultramafic intrusion is among the most promising intrusions hosting Fe-Ti oxide ores in Mozambique. Fe-Ti oxide ores are mainly composed of ilmenite occurring as lenses, veins and layers, either massive or disseminated in hornblende pyroxenite. This study discusses the nature and origin of the intrusion and related ilmenite ore body on the basis of whole-rock and mineral chemistry. Textural and structural evidences support a cumulate origin for these rocks, including the occurrence of relict cumulate textures, layering of alternating oxides and silicate-rich rocks, and size-grading of silicate-rich layers. Primary magmatic features have, however, largely been overprinted by subsolidus processes. The occurrence of the cumulate assemblage (Fe-Ti oxides and clinopyroxene), without plagioclase and olivine, suggests that the magma underwent differentiation before its emplacement. The evolved magmatic nature of the intrusion is consistent with the calculated Mg-number of approximately 50 for the melt in equilibrium with clinopyroxene crystals. The high TiO2 concentrations (>4 wt%) of the evolved magma, by differentiation, are interpreted as the main factors controlling the crystallization of Fe-Ti oxides. We propose that the ores formed from crystallization and settling of Fe-Ti oxide minerals from an evolved basaltic magma. This model is consistent with (1) the occurrence of Fe-Ti oxides and clinopyroxene as cumulates in relation to the coexisting amphibole, (2) the layering structures of alternating oxides and silicate matrix, (3) the scarcity of apatite supported by the extremely low whole-rock P2O5 concentrations and (4) the restricted occurrence of ore veins, excluding the formation from immiscible oxide melts. |
|
言語 |
en |
| 出版タイプ |
|
|
出版タイプ |
VoR |
|
出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
| 書誌情報 |
en : Ore Geology Reviews
巻 143,
発行日 2022
|
| 収録物識別子 |
|
|
収録物識別子タイプ |
ISSN |
|
収録物識別子 |
01691368 |
| 出版者 |
|
|
出版者 |
Elsevier B.V. |
| 関連情報 |
|
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
https://doi.org/10.1016/j.oregeorev.2022.104760 |
| 権利情報 |
|
|
権利情報 |
© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
kokuA_2022_6.pdf (25.4 MB)
