scholarly journals An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean)

2008 ◽  
Vol 9 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. Bascou ◽  
G. Delpech ◽  
A. Vauchez ◽  
B. N. Moine ◽  
J. Y. Cottin ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Lithospheric Mantle ◽  
Seismic Properties ◽  
Kerguelen Plume ◽  
Integrated Study

Forsterite reprecipitation and carbon dioxide entrapment in the lithospheric mantle during its interaction with carbonatitic melt: a case study from the Sung Valley ultramafic–alkaline–carbonatite complex, Meghalaya, NE India

2020 ◽  
pp. 1-12
Author(s):  
Shubham Choudhary ◽  
Koushik Sen ◽  
Santosh Kumar ◽  
Shruti Rana ◽  
Swakangkha Ghosh
Keyword(s):  
Carbon Dioxide ◽  
Lithospheric Mantle ◽  
Experimental Studies ◽  
Carbonatite Complex ◽  
Kerguelen Plume ◽  
Ne India ◽  
Isotopic Analyses ◽  
Oxygen Isotopic ◽  
Carbonatite Magma

Abstract Carbonatite melts derived from the mantle are enriched in CO2- and H2O-bearing fluids. This melt can metasomatize the peridotitic lithosphere and liberate a considerable amount of CO2. Experimental studies have also shown that a CO2–H2O-rich fluid can form Fe- and Mg-rich carbonate by reacting with olivine. The Sung Valley carbonatite of NE India is related to the Kerguelen plume and is characterized by rare occurrences of olivine. Our study shows that this olivine is resorbed forsterite of xenocrystic nature. This olivine bears inclusions of Fe-rich magnesite. Accessory apatite in the host carbonatite contains CO2–H2O fluid inclusions. Carbon and oxygen isotopic analyses indicate that the carbonatites are primary igneous carbonatites and are devoid of any alteration or fractionation. We envisage that the forsterite is a part of the lithospheric mantle that was reprecipitated in a carbonatite reservoir through dissolution–precipitation. Carbonation of this forsterite, during interaction between the lithospheric mantle and carbonatite melt, formed Fe-rich magnesite. CO2–H2O-rich fluid derived from the carbonatite magma and detected within accessory apatite caused this carbonation. Our study suggests that a significant amount of CO2 degassed from the mantle by carbonatitic magma can become entrapped in the lithosphere by forming Fe- and Mg-rich carbonates.

Platinum-group elements and the multistage metasomatic history of Kerguelen lithospheric mantle (South Indian Ocean)

2004 ◽  
Vol 208 (1-4) ◽  
pp. 195-215 ◽  
Author(s):  
Jean-Pierre Lorand ◽  
Guillaume Delpech ◽  
Michel Grégoire ◽  
Bertrand Moine ◽  
Suzanne Y O'Reilly ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Lithospheric Mantle ◽  
Platinum Group Elements ◽  
South Indian Ocean ◽  
South Indian ◽  
History Of ◽  
Platinum Group

Petrofabric and seismic properties of lithospheric mantle xenoliths from the Calatrava volcanic field (Central Spain)

2016 ◽  
Vol 683 ◽  
pp. 200-215 ◽  
Author(s):  
P. Puelles ◽  
B. Ábalos ◽  
J.I. Gil Ibarguchi ◽  
F. Sarrionandia ◽  
M. Carracedo ◽  
...  
Keyword(s):  
Lithospheric Mantle ◽  
Volcanic Field ◽  
Mantle Xenoliths ◽  
Central Spain ◽  
Seismic Properties

Hunting down the late Miocene-early Pliocene biogenic bloom in the Tasman Sea: an integrated study at IODP Site U1506

2021 ◽  
Author(s):  
Maria Elena Gastaldello ◽  
Claudia Agnini ◽  
Edoardo Dallanave ◽  
Thomas Westerhold ◽  
Adriane R. Lam ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Late Miocene ◽  
Integrated Approach ◽  
Marine Geology ◽  
Calcareous Nannofossils ◽  
Low Oxygen ◽  
Precise Position ◽  
Early Pliocene ◽  
Tasman Sea ◽  
Integrated Study

<p>The latest Miocene-early Pliocene biogenic bloom is a poorly understood paleoceanographic event that has been traditionally related to increased primary productivity; and associated changes in the marine carbon cycle. In order to identify this event in the Tasman Sea, we carried out an integrated study at IODP Site U1506. First, we have constructed an age model based on an integrated approach (i.e. biostratigraphy, astrocyclostratigraphic tuning). This permits the identification of the precise position as well as the duration of the biogenic bloom in the Tasman Sea but also the calculation of sedimentation rates across the study interval. In this framework, we generated quantitative micropaleontological records (benthic and planktic foraminifera and calcareous nannofossils) and a low-resolution carbon and oxygen stable isotope records on <em>Cibicidoides mundulus</em> and <em>Trilobatus sacculifer</em> across an interval spanning from 233.50 to 81.75 m CSF-A (Tortonian, late Miocene to Zanclean, early Pliocene). Quantitative assemblage work and statistical analyses on the resulting dataset point to increased export productivity in the lower part of the interval (between CNM15 and CNM18, Backman et al., 2012), as inferred from benthic foraminiferal assemblages dominated by taxa (e.g. <em>Uvigerina</em> and <em>Ehrenbergina</em>) that have been reported to be common across the biogenic bloom in the Indian Ocean (Dickens and Owen, 1999). The paleoecological analysis of these assemblages suggests eutrophic conditions at the seafloor and low oxygen concentration of bottom waters.</p><p><strong>Reference</strong></p><p>Backman, J., Raffi, I., Rio, D., Fornaciari, E., & Pälike, H., 2012. Biozonation and biochronology of Miocene through Pleistocene calcareous nannofossils from low and middle latitudes. Newsletters on Stratigraphy, 45(3), 221–244.</p><p>Dickens, G.R. and Owen, R.M., 1999. The latest Miocene-early Pliocene biogenic bloom: A revised Indian Ocean perspective. Marine Geology, 161: 75-91.</p><p><strong>Acknowledgments</strong></p><p>University of Padova DOR grant, CARIPARO Foundation Phd scholarship.</p><p>Spanish Ministry of Economy and Competitiveness and FEDER funds (PID2019-105537RB-I00).<strong> </strong></p>

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