|
|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Engineering / Faculty of Engineering >
Peer-reviewed Journal Articles, etc >
Magmatic-Hydrothermal Processes Associated with Rare Earth Element Enrichment in the Kangankunde Carbonatite Complex, Malawi
This item is licensed under:Creative Commons Attribution 4.0 International
| Title: | Magmatic-Hydrothermal Processes Associated with Rare Earth Element Enrichment in the Kangankunde Carbonatite Complex, Malawi |
| Authors: | Chikanda, Frances Browse this author | | Otake, Tsubasa Browse this author →KAKEN DB | | Ohtomo, Yoko Browse this author →KAKEN DB | | Ito, Akane Browse this author | | Yokoyama, Takaomi D. Browse this author | | Sato, Tsutomu Browse this author →KAKEN DB |
| Keywords: | carbonatite | | REE enrichment | | Fe, C, and O isotopes | | magmatic-hydrothermal |
| Issue Date: | Jul-2019 |
| Publisher: | MDPI |
| Journal Title: | Minerals |
| Volume: | 9 |
| Issue: | 7 |
| Start Page: | 442 |
| Publisher DOI: | 10.3390/min9070442 |
| Abstract: | Carbonatites undergo various magmatic-hydrothermal processes during their evolution that are important for the enrichment of rare earth elements (REE). This geochemical, petrographic, and multi-isotope study on the Kangankunde carbonatite, the largest light REE resource in the Chilwa Alkaline Province in Malawi, clarifies the critical stages of REE mineralization in this deposit. The delta Fe-56 values of most of the carbonatite lies within the magmatic field despite variations in the proportions of monazite, ankerite, and ferroan dolomite. Exsolution of a hydrothermal fluid from the carbonatite melts is evident based on the higher delta Fe-56 of the fenites, as well as the textural and compositional zoning in monazite. Field and petrographic observations, combined with geochemical data (REE patterns, and Fe, C, and O isotopes), suggest that the key stage of REE mineralization in the Kangankunde carbonatite was the late magmatic stage with an influence of carbothermal fluids i.e. magmatic-hydrothermal stage, when large (similar to 200 mu m), well-developed monazite crystals grew. The C and O isotope compositions of the carbonatite suggest a post-magmatic alteration by hydrothermal fluids, probably after the main REE mineralization stage, as the alteration occurs throughout the carbonatite but particularly in the dark carbonatites. |
| Rights: | © 2019 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/). | | http://creativecommons.org/licenses/by/4.0/ |
| Type: | article |
| URI: | http://hdl.handle.net/2115/75443 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 佐藤 努
|
