Results 21 to 30 of about 86 (81)

Material aspects of kimberlite rocks productivity

open access: yesМінеральні ресурси України, 2017
Most of investigated kimberlite diatremes of the Siberian platform represent multiphase pipes. Each magmatic phase of intrusion, formed inside diatremes, is composed by kimberlites with specific petrographic and petrochemical type possessing a number of ...
M. M. Zinchuk
doaj  

The Complexity of Deep Aqueous Fluids in Planetary Ultramafic Mantles

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 7, July 2026.
Abstract Planetary volatiles cycle through a planet's crust, mantle, and atmosphere, playing a crucial role in surface processes and habitability. Discussions of planetary volatiles traditionally focus on water, carbon, nitrogen, and sulfur, but fluids in contact with silicate rocks and ultramafic mantles can contain significant amounts of magnesium ...
Sophia E. Economon   +1 more
wiley   +1 more source

Emplacement of Hybrid Continental‐Oceanic Arc Terranes Without Collision: The Devonian Calliope Arc (New England Orogen, Australia)

open access: yesTectonics, Volume 45, Issue 7, July 2026.
Abstract The accretion of allochthonous provinces, derived from oceanic plates, has traditionally been considered an important contributor to continental growth. However, increasing evidence shows that some oceanic terranes (e.g., island arcs) are not “exotic,” as suggested by the presence of continental‐derived sedimentary provenance.
Igor V. Gomes   +4 more
wiley   +1 more source

Polymict melt‐bearing breccia dikes in the Morokweng impact structure formed by slip‐induced mechanical mixing of pseudotachylite and cataclasite along large‐displacement impact faults

open access: yesMeteoritics &Planetary Science, Volume 61, Issue 7, Page 1288-1308, July 2026.
Abstract A core drilled through shocked and faulted Archean granitoid gneisses and dolerites in the eroded peak ring of the 70–80 km diameter Morokweng impact structure intersects multiple centimeter‐ to meter‐wide clastic‐matrix breccias containing a polymict clast population of lithic and mineral clasts and altered, millimeter‐ to centimeter ‐size ...
Roger L. Gibson   +3 more
wiley   +1 more source

A few thoughts on the diamondiferous nature of lamprophyres from Wajrakarur Kimberlite Field, Southern India

open access: yesMineralogia
Lamprophyre Clan Rocks (LCRs) such as lamprophyres, lamproites and kimberlites are reported from many parts of the cratonic areas in India, especially the diamondiferous Eastern Dharwar Craton (EDC).
Phani P. Ramesh Chandra   +1 more
doaj   +1 more source

Impact‐diagnostic criteria for use in confirming a meteorite impact origin of terrestrial geological structures: Recommendations by the Impact Cratering Committee of the Meteoritical Society

open access: yesMeteoritics &Planetary Science, Volume 61, Issue 7, Page 1538-1565, July 2026.
Abstract The framework of the Impact Cratering Committee (ICC) of the Meteoritical Society was approved in 2020, with the first committee members appointed in 2023. The ICC has a mandate to (1) approve, maintain, and update a database of confirmed terrestrial meteorite impact structures, (2) define and regularly update the criteria used for ...
A. J. Cavosie   +11 more
wiley   +1 more source

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

open access: yesNew 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

Geochemical and Isotopic Constraints on Long‐Lived Source Enrichment and Mantle Evolution in Paleoproterozoic Cratonic Lamprophyres

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 6, June 2026.
Abstract The cratonic lithospheric mantle records complex metasomatic processes and is frequently tapped by alkaline magmatism, offering a unique opportunity to trace the progressive evolution of the mantle. In the present contribution, we investigate a newly identified calc‐alkaline lamprophyre field from the Neoarchean Jonnagiri Schist Belt, Eastern ...
Sourav Naskar   +6 more
wiley   +1 more source

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

open access: yesRapid 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   +4 more
wiley   +1 more source

Active Plume, Abandoned Ridge, or Ancient Slab? olivine‐Hosted Melt Inclusions Record the Mantle Melting Conditions Below the East Pacific Revillagigedo Archipelago, Mexico

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 4, April 2026.
Abstract The voluminous active volcanoes of the Revillagigedo Islands of Socorro and San Benedicto in the east Pacific Ocean exhibit hotspot geochemistry. However, the presence of a deep mantle plume has not been seismologically confirmed. Instead, a fossil subducted slab is identified in the lower mantle underneath the volcanoes. Moreover, the islands
Janne M. Koornneef   +7 more
wiley   +1 more source

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