Disequilibrium in historic volcanic rocks from Fogo, Cape Verde traces carbonatite metasomatism of recycled ocean crust
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Disequilibrium in historic volcanic rocks from Fogo, Cape Verde traces carbonatite metasomatism of recycled ocean crust. / Barker, A. K.; Magnusson, E.; Troll, V. R.; Harris, C.; Mattsson, H. B.; Holm, P. M.; Perez-Torrado, F. J.; Carracedo, J. C.; Deegan, F. M.
I: Lithos, Bind 456-457, 107328, 2023.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Disequilibrium in historic volcanic rocks from Fogo, Cape Verde traces carbonatite metasomatism of recycled ocean crust
AU - Barker, A. K.
AU - Magnusson, E.
AU - Troll, V. R.
AU - Harris, C.
AU - Mattsson, H. B.
AU - Holm, P. M.
AU - Perez-Torrado, F. J.
AU - Carracedo, J. C.
AU - Deegan, F. M.
N1 - Publisher Copyright: © 2023 The Authors
PY - 2023
Y1 - 2023
N2 - Fogo, Cape Verde, located upon thick oceanic lithosphere, provides a window into processes occurring in the mantle where recycled ocean crust in an upwelling mantle plume interacts with ambient mantle. Our objective is to investigate the nature of the lithologies of the mantle sources involved in the petrogenesis of historic volcanic rocks from Fogo. We observe enclaves and mingling textures in the lavas combined with oxygen isotope disequilibrium between olivine and clinopyroxene phenocrysts. Olivine δ18O values display positive correlations with Zr/Hf and Zr/Y and a negative correlation with U/Th, whereas clinopyroxene δ 18O values correlate positively with Ba/Nb. Heterogeneity between crystal populations and within the groundmass indicates that multiple magma batches are mixed beneath Fogo. In terms of mantle endmembers and source lithologies, a HIMU endmember was generated by melting of carbonated eclogite as indicated by low δ 18O values, Zr/Hf, Ba/Nb and high U/Th ratios. In contrast, we show the EM1 endmember has high δ 18O, Zr/Hf, Ba/Nb and low U/Th ratios, derived from melting of variably carbonated peridotite. Additionally, Ba/Th ratio are high, indicating that carbonatite melts have contributed to alkaline magma compositions at Fogo.
AB - Fogo, Cape Verde, located upon thick oceanic lithosphere, provides a window into processes occurring in the mantle where recycled ocean crust in an upwelling mantle plume interacts with ambient mantle. Our objective is to investigate the nature of the lithologies of the mantle sources involved in the petrogenesis of historic volcanic rocks from Fogo. We observe enclaves and mingling textures in the lavas combined with oxygen isotope disequilibrium between olivine and clinopyroxene phenocrysts. Olivine δ18O values display positive correlations with Zr/Hf and Zr/Y and a negative correlation with U/Th, whereas clinopyroxene δ 18O values correlate positively with Ba/Nb. Heterogeneity between crystal populations and within the groundmass indicates that multiple magma batches are mixed beneath Fogo. In terms of mantle endmembers and source lithologies, a HIMU endmember was generated by melting of carbonated eclogite as indicated by low δ 18O values, Zr/Hf, Ba/Nb and high U/Th ratios. In contrast, we show the EM1 endmember has high δ 18O, Zr/Hf, Ba/Nb and low U/Th ratios, derived from melting of variably carbonated peridotite. Additionally, Ba/Th ratio are high, indicating that carbonatite melts have contributed to alkaline magma compositions at Fogo.
KW - Carbonated eclogite
KW - Fogo, Cape Verde
KW - Magma hybridization
KW - Mantle heterogeneity
KW - Oxygen isotopes
KW - Volcanic rocks
U2 - 10.1016/j.lithos.2023.107328
DO - 10.1016/j.lithos.2023.107328
M3 - Journal article
AN - SCOPUS:85168347883
VL - 456-457
JO - Lithos
JF - Lithos
SN - 0024-4937
M1 - 107328
ER -
ID: 365883477