Search results for " mantle plume"

showing 3 items of 3 documents

Strongly SiO2-undersaturated, CaO-rich kamafugitic Pleistocene magmatism in Central Italy (San Venanzo volcanic complex) and the role of shallow dept…

2020

The Pleistocene (~460–265 ka) San Venanzo volcanic complex belongs to the IAP (Intra-Apennine Province) in central Italy, which comprises at least four small Pleistocene monogenetic volcanoes plus several unrooted pyroclastic deposits with peculiar mineralogical and whole-rock chemical compositions. San Venanzo products are strongly SiO2-undersaturated, CaO- and MgO-rich and show ultrapotassic serial character. The relatively common occurrence of calcite in the pyroclastic rocks and the overall high CaO content are interpreted in literature as primary mineral. The main rock facies at San Venanzo are calcite-rich scoria and lapilli tuffs, with minor massive lava flows, and a rare pegma…

010504 meteorology & atmospheric sciencesultrapotassicGeochemistryPyroclastic rockCarbonatite; Kamafugite; mantle plumes; noble gases; Roman comagmatic region; subduction; ultrabasic; ultrapotassicengineering.material010502 geochemistry & geophysicsKamafugite01 natural sciencesUltramafic rockCarbonatiteultrabasicRoman comagmatic region0105 earth and related environmental sciencesPeridotitegeographygeography.geographical_feature_categoryFractional crystallization (geology)Olivinemantle plumesVolcanic rockIgneous rocknoble gasesengineeringGeneral Earth and Planetary SciencesLeucitesubductionGeology
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Geochemical characteristics of Cretaceous carbonatites from Angola

1999

Abstract The Early Cretaceous (138–130 Ma) carbonatites and associated alkaline rocks of Angola belong to the Parana-Angola-Etendeka Province and occur as ring complexes and other central-type intrusions along northeast trending tectonic lineaments, parallel to the trend of coeval Namibian alkaline complexes. Most of the Angolan carbonatite-alkaline bodies are located along the apical part of the Mocamedes Arch, a structure representing the African counterpart of the Ponta Grossa Arch in southern Brazil, where several alkaline-carbonatite complexes were also emplaced in the Early Cretaceous. Geochemical and isotopic (C, 0, Sr and Nd) characteristics determined for five carbonatitic occurren…

Lineamentgenetic-relationshipsGeologyeastern paraguaypotassic magmatismStructural basintrindade mantle plumeMantle (geology)Cretaceousse brazilsr-nd isotopesPaleontologyTectonicscomplex; eastern paraguay; evolution; genetic-relationships; igneous rocks; northwestern namibia; potassic magmatism; se brazil; sr-nd isotopes; trindade mantle plumenorthwestern namibiaevolutionigneous rocksCarbonatiteMetasomatismcomplexGeologyEarth-Surface ProcessesJournal of African Earth Sciences
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Noble gas and CO2 isotopic signatures of the lithospheric mantle underneath Mexico and the Canary Islands: clues from mantle xenoliths and arc lavas

2022

Studying the isotopic composition of fluids trapped in mantle xenoliths opens avenues to understand the origin and cycling of volatiles in the Earth’s upper mantle. In this PhD dissertation, new and in most cases the very first data regarding the isotopic (noble gases and CO2) characterization of the lithospheric mantle portions of three different geodynamic environments are presented: (i) Central and NW Mexico, a continental setting dominated by extension; (ii) the Transmexican Volcanic Belt (TMVB) a subduction setting, and (iii) the Canary Islands, particularly El Hierro and Lanzarote, two oceanic islands formed by mantle plume-derived intraplate volcanism. In total 32 peridotites (includ…

Mexico Canary Islands lithospheric mantle subduction mantle plume continental rift Basin and Range volcanism mantle xenoliths fluid inclusions noble gas isotopes carbon isotopes carbon recycling refertilization.Settore GEO/08 - Geochimica E Vulcanologia
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