The Iriba alkaline basalts, an expression of mantle-derived Cretaceous magmatism of the Cameroon-Chad volcanic line along the Central Africa Rift System
The poorly documented volcanic rocks of the Ouaddai massif in Chad are a continuity of the ones of the Cameroon Volcanic Line further to the SE, located within the Central African rift system. New mineralogical and geochemical data from the Iriba basanites (SiO2: 41–45 wt%) show depletion in HREE, s...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Académie des sciences
2024-12-01
|
| Series: | Comptes Rendus. Géoscience |
| Subjects: | |
| Online Access: | https://comptes-rendus.academie-sciences.fr/geoscience/articles/10.5802/crgeos.282/ |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The poorly documented volcanic rocks of the Ouaddai massif in Chad are a continuity of the ones of the Cameroon Volcanic Line further to the SE, located within the Central African rift system. New mineralogical and geochemical data from the Iriba basanites (SiO2: 41–45 wt%) show depletion in HREE, slight negative Sm anomaly and high LREE/HREE ratios, which is typical of OIB. The main differentiation process is fractional crystallization with a complete lack of crustal contamination. These features, similar to basanites exposed in southern Cameroon, reflect the partial melting of a metasomatized subcontinental lithospheric root reworked during the formation of the Cenozoic Central Africa Rift System. We propose to define by Cameroon-Chad Volcanic Line this continental scale structure controlling the emplacement of alkaline magmas. |
|---|---|
| ISSN: | 1778-7025 |