Formation and evolution of flood basalt magmas – combining geochemical data with the magnetic stratigraphy of the Deccan large igneous province
Final Report Abstract
Within the project Patrick Hoyer analysed some 250 volcanic rocks from the Deccan flood basalts obtained from the paleomagnetic work of Prof. F. Fluteau and colleagues as well as from the submarine Rio Grande Rise (RGR) obtained during the MSM82 cruise in 2019. These data were used to study on the one hand the magmatic processes during the formation of continental flood basalts and on the other hand the formation of an oceanic plateau. The results show: 1) that the lava flows of the Rajahmundry area represent the extension of the voluminous Deccan formations (Poladpur, Ambenali and Mahabaleshwar), 2) that four magmatic sequences of the Deccan main lava formations each lasting ~104 to ~105 yrs indicate repeated episodes of melt recharge, mixing, and eruption of variably evolved magmas from relatively small crustal magma reservoirs, 3) that the RGR formed by two magmatic stages erupting (1) tholeiitic and (2) alkaline lavas that reflect a change from high degrees of shallow mantle melting at a plumeinfluenced spreading centre to intraplate volcanism, 4) that mantle plumes can split into distinct upper mantle conduits, and provide evidence that these plumelets formed at the plume head-to-plume tail transition, possibly originating at the African Large Low-Shear-Velocity Province.
Publications
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Machine learning-based re-classification of the geochemical stratigraphy of the Rajahmundry Traps, India. Journal of Volcanology and Geothermal Research, 428, 107594.
Hoyer, Patrick A.; Regelous, Marcel; Adatte, Thierry & Haase, Karsten M.
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Mantle plume and rift-related volcanism during the evolution of the Rio Grande Rise. Communications Earth & Environment, 3(1).
Hoyer, Patrick A.; Haase, Karsten M.; Regelous, Marcel; O.’Connor, John M.; Homrighausen, Stephan; Geissler, Wolfram H. & Jokat, Wilfried
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Evidence for compositionally distinct upper mantle plumelets since the early history of the Tristan-Gough hotspot. Nature Communications, 14(1).
Homrighausen, Stephan; Hoernle, Kaj; Hauff, Folkmar; Hoyer, Patrick A.; Haase, Karsten M.; Geissler, Wolfram H. & Geldmacher, Jörg
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Systematic and Temporal Geochemical Changes in the Upper Deccan Lavas: Implications for the Magma Plumbing System of Flood Basalt Provinces. Geochemistry, Geophysics, Geosystems, 24(2).
Hoyer, P. A.; Haase, K. M.; Regelous, M. & Fluteau, F.
