Results 31 to 40 of about 10,467 (267)

Oceanic Slab Melting and Mantle Metasomatism [PDF]

Science Progress, 2001
Modern plate tectonic brings down oceanic crust along subduction zones where it either dehydrates or melts. Those hydrous fluids or melts migrate into the overlying mantle wedge trigerring its melting which produces arc magmas and thus additional continental crust. Nowadays, melting seems to be restricted to cases of young (<50 Ma) subducted plates.
Scaillet, Bruno, Prouteau, Gaëlle
openaire   +3 more sources

Petrogenetic evidences in geodynamics and placement of Nordoz intrusive masses in Alborz-Azerbaijan structural zone

Journal of Economic Geology
The Oligocene Nordoz intrusive complex is located in the eastern region of Siehroud, within the East Azerbaijan province, and within the Alborz-Azerbaijan structural zone.
Shahryar Mahmoudi , Shiva Lavi, Shohreh Hassanpour, Amir Ali Tabakh Shabani , Mehran Yegane Far   +4 more
doaj   +1 more source

The Relationship Between Kimberlitic Magmatism and Electrical Conductivity Anomalies in the Mantle

Geophysical Research Letters, 2022
Kimberlites are igneous rocks whose formation remains enigmatic due to their severely altered nature, highly variable compositions and rapid ascent through the lithosphere.
Sinan Özaydın, Kate Selway
doaj   +1 more source

Mineralogical evolution of the northern Bossoroca ophiolite, São Gabriel terrane

Brazilian Journal of Geology, 2020
Mineralogical evolution of ophiolites is significant to understand paleo-oceanic crust and mantle requiring multi-proxy techniques to identify steps in the processes. We studied the Bossoroca ophiolite from the southern Brasiliano Orogen, a prime example
Amanda Juliano Massuda, Léo Afraneo Hartmann, Gláucia Nascimento Queiroga, Marco Paulo de Castro, Carolina Gonçalves Leandro, Jairo Francisco Savian   +5 more
doaj   +1 more source

Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia)

Geosciences, 2018
This article is devoted to the geology of titanium-rich varieties of the Petyayan-Vara rare-earth dolomitic carbonatites in Vuoriyarvi, Northwest Russia. Analogues of these varieties are present in many carbonatite complexes. The aim of this study was to
Evgeniy Kozlov, Ekaterina Fomina, Mikhail Sidorov, Vladimir Shilovskikh   +3 more
doaj   +1 more source

Thallium Isotopes Reveal Brine Activity During Carbonatite Magmatism

Geochemistry, Geophysics, Geosystems, 2021
Carbonatite volcanism remains poorly understood compared to silicic volcanism due to the scarcity of carbonatite volcanoes worldwide and because volcanic H2O and CO2—major components in carbonatite volcanic systems—are not well preserved in the rock ...
Forrest Horton, Sune Nielsen, Yunchao Shu, Alan Gagnon, Jerzy Blusztajn   +4 more
doaj   +1 more source

Phlogopite-Forming Reactions as Indicators of Metasomatism in the Lithospheric Mantle

Minerals, 2019
Phlogopite is widely accepted as a major mineral indicator of the modal metasomatism in the upper mantle within a very wide P–T range. The paper reviews data on various phlogopite-forming reactions in upper-mantle peridotites.
O. Safonov, V. Butvina, E. Limanov
semanticscholar   +1 more source

Xenoliths in the alkali basalts of Makhtesh Ramon of Desert Negev (Israel) as indicators of mantle metasomatosis and magma generation

Литосфера, 2016
Xenoliths in the Early Cretaceous alkali basalts of Makhtesh Ramon basin (southern Israel) are represented by essentially olivine rocks: dunite (usually including clinopyroxen) - 5% of the total amount, lherzolite - 21%, wehrlite - 28%, clinopyroxenite -
G. B. Fershtater, Z. A. Yudalevich, V. V. Khiller   +2 more
doaj   +2 more sources

Geochemistry and Geochronology of A‐Type Intermediate‐Felsic Rocks in NW Himalaya, Pakistan: Implications for Petrogenesis and Tectonic Evolution of Northern Gondwana

Geochemistry, Geophysics, Geosystems
Igneous intrusives in northern Pakistan can provide valuable insights into pre‐Himalayan metaluminous to peraluminous magmatism along the northern boundary of the supercontinent Gondwana and its potential tectonic significance.
Musa Khan, Huan Li, Thomas J. Algeo, Asad Khan, Michael W. Förster, Zaheen Ullah   +5 more
doaj   +1 more source

AFRP20: New P‐Wavespeed Model for the African Mantle Reveals Two Whole‐Mantle Plumes Below East Africa and Neoproterozoic Modification of the Tanzania Craton

Geochemistry, Geophysics, Geosystems, 2021
Africa's Cenozoic tectonism is often attributed to mantle plumes, particularly below East Africa, but their morphology, number, location, and impact on the African lithosphere are debated.
A. Boyce, I. D. Bastow, S. Cottaar, R. Kounoudis, J. Guilloud De Courbeville, E. Caunt, S. Desai   +6 more
doaj   +1 more source