2024-03-29T09:11:20Z
https://u-ryukyu.repo.nii.ac.jp/oai
oai:u-ryukyu.repo.nii.ac.jp:02003766
2022-10-31T01:43:28Z
1642837622505:1642837957109:1642837978461
1642838403551:1642838406414
Petrochemical evidence for diversity of magma compositions at the northwestern Ethiopian volcanic province
Meshesha, Agonafir Daniel
Shinjo, Ryuichi
新城, 竜一
open access
Petrographic characteristics and whole-rock major and trace element data are presented for the Bure volcanic rocks from the northwestern Ethiopian plateau of East Africa continental flood basalt province, to investigate the processes that involved in the genesis of the erupted magma and its source composition during plume-induced continental rifting. The Bure area is mainly composed of stratified basalts, recent basalts, scoria cones and trachyte plugs. The successions of the erupted basalts are from transitional tholeiites to alkaline basalts. The transitional tholeiites have higher Zr/Nb (8.88-21.86) and Rb/Nb (0.66-1.87) than those of the alkaline (Zr/Nb=2.19-6.21, Rb/Nb=0.26-0.74), indicating that they are originated from distinct magma sources. The compositional variation in the transitional tholeiites cannot be explainable in terms of fractional crystallization of common (or similar) primary magma; instead it reflects the involvement of various mantle and crustal components in their petrogenesis. By contrast, the variation in the alkali suite can be explained by dominant fractional crystallization process of OIB-like primary basalts that derived from the Afar mantle plume. The strong lithospheric signature observed in the transitional tholeiites suggests pronounce interaction between the Afar plume and the lithosphere at the initial stage of continental break-up.
紀要論文
琉球大学理学部
2004-09
eng
departmental bulletin paper
VoR
http://hdl.handle.net/20.500.12000/5381
http://hdl.handle.net/20.500.12000/5381
https://u-ryukyu.repo.nii.ac.jp/records/2003766
0286-9640
AN00250774
琉球大学理学部紀要
Bulletin of the College of Science. University of the Ryukyus
78
251
266
https://u-ryukyu.repo.nii.ac.jp/record/2003766/files/No78p251.pdf