Results 61 to 70 of about 24,088 (309)

Petrogenetic processes in the ultramafic, alkaline and carbonatitic magmatism in the Kola Alkaline Province: a review [PDF]

, 2005
Igneous rocks of the Devonian Kola Alkaline Carbonatite Province (KACP) in NW Russia and eastern Finland can be classified into four groups: (a) primitive mantle-derived silica-undersaturated silicate magmas; (b) evolved alkaline and nepheline syenites; (
Balaganskaya, E., Beard, Andy, Demaiffe, D., Downes, Hilary, Liferovich, R.   +4 more
core   +1 more source

Extensive Magmatic Heating of the Lithosphere Beneath the Hawaiian Islands Inferred From Salt Lake Crater Mantle Xenoliths

Geochemistry, Geophysics, Geosystems, 2020
An ongoing challenge in studies of the oceanic upper mantle is how intraplate hotspots impact the thermal structure of the lithosphere. To address this issue at the Hawaiian hotspot, we analyze mineral compositions for a petrographically diverse suite of
Imani Guest, Garrett Ito, Michael O. Garcia, Eric Hellebrand   +3 more
doaj   +1 more source

Measured and calculated seismic velocities and densities for granulites from xenolith occurrences and adjacent exposed lower crustal sections: A comparative study from the North China craton [PDF]

, 2000
Granulites from the Neogene xenolith-bearing Hannuoba alkaline basalt and from the Manjinggou-Wayaokou exposed lower crustal section in the Archean Huai'an terrain, which occurs within and surrounds the Hannuoba basalt, provide a unique opportunity for a
Feng, JL, Gao, S, Jin, SY, Jin, ZM, Kern, H, Liu, YS, Popp, T, Sun, M, Zhao, ZB   +8 more
core   +1 more source

Thinning and Heating of Laramide Continental Lower Crust Recorded by Zircon Petrochronology

Geochemistry, Geophysics, Geosystems
Zircon grains from the metasedimentary lower crust of the Rio Grande Rift, New Mexico, preserve a metamorphic record of the transition from Laramide compression to Eocene extension.
J. H. Cipar, A. J. Smye, J. M. Garber, J. R. Reimink, A. R. C. Kylander‐Clark   +4 more
doaj   +1 more source

The Origins of Yakutian Eclogite Xenoliths [PDF]

Journal of Petrology, 1997
Abstract Owing to the association with diamonds, eclogite xenoliths have received disproportionate attention given their low abundance in kimberlites. Several hypotheses have been advanced for the origin of eclogite xenoliths, from the subduction and high-pressure melting of oceanic crust, to cumulates and liquids derived from the ...
Gregory A. Snyder, Lawrence A. Taylor, Ghislaine Crozaz, Alex N. Halliday, Brian L. Beard, Vladimir N. Sobolev, Nikolai V. Sobolev   +6 more
openaire   +1 more source

Progressively Fenitised Schist and Carbonatitic Clasts From a Metasomatic Aureole Beneath the Alkalic Dunedin Volcano, Otago, New Zealand

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Clasts of albite‐porphyroblastic quartzofeldspathic schist, derived from the Otago Schist basement, occur within the Port Chalmers Breccia, a diatreme at the centre of the Dunedin stratovolcano, New Zealand. Schists have undergone varying degrees of replacement reactions (at temperatures of 300° to >500°C) producing hornfelses, with Ca‐ and K‐enriched ...
Alan F. Cooper
wiley   +1 more source

Evidence for suboceanic small-scale convection from a “garnet”-bearing lherzolite xenolith from Aitutaki Island, Cook Islands

Progress in Earth and Planetary Science
Garnet peridotite xenoliths have been rarely reported from suboceanic mantle. Petrographic and geochemical characteristics of garnet-bearing oceanic peridotite xenoliths provide precious information on dynamics of the suboceanic lithosphere and ...
Norikatsu Akizawa, Kazuhito Ozawa, Tetsu Kogiso, Akira Ishikawa, Akira Miyake, Yohei Igami, Simon R. Wallis, Takayoshi Nagaya, Chihiro Ohshima, Ryo Fujita, Tatsuhiko Kawamoto, Akihiro Tamura, Tomoaki Morishita, Shoji Arai, Atsushi Yasumoto   +14 more
doaj   +1 more source

The geochemical features and oxygen isotope composition of eclogite and clinopyroxenite xenoliths from kimberlite pipes of Siberian craton [PDF]

, 2021
Tatiana Kalashnikova, S. I. Kostrovitsky, Lidiya Solovieva, Konstantin Sinitsyn, Elvira Yudintseva   +4 more
openalex   +1 more source

Deciphering petrogenic processes using Pb isotope ratios from time-series samples at Bezymianny and Klyuchevskoy volcanoes, Central Kamchatka Depression [PDF]

, 2016
The Klyuchevskoy group of volcanoes in the Kamchatka arc erupts compositionally diverse magmas (high-Mg basalts to dacites) over small spatial scales.
Bachmann, Olivier, Bauer, Ann Melissa, Izbekov, Pavel E., Kayzar, Theresa M., Nelson, Bruce K.   +4 more
core   +1 more source

Combustion and Pyrolysis EA‐IRMS Techniques to Determine the δ2H of Diamonds

Rapid Communications in Mass Spectrometry, Volume 40, Issue 10, 30 May 2026.
ABSTRACT Rationale Diamonds are generally considered to be metasomatic minerals originating from the Earth's mantle. They formed through the interaction of carbon‐bearing fluids or melts with the surrounding deep lithology. Most knowledge about the formation of diamonds comes from studying their mineral inclusions or stable isotopes.
François Fourel, Christophe Lécuyer, Emilie Thomassot, Etienne Deloule, Charles Ojeimi   +4 more
wiley   +1 more source