Results 31 to 40 of about 16,578 (144)

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

The carbonate fraction in carbonatitic Italian lamprophyres

open access: yes, 2005
Alkaline and ultramafic lamprophyres represent the majority of pre-Pleistocene alkaline mafic magmatic activity in Italy and have been described from several localities. The age of magmatism ranges from Triassic to Lower Oligocene.
STOPPA, Francesco, WALL F., VICHI G.
core   +1 more source

PALEOZOIC INTRAPLATE MAGMATISM OF THE EAST EUROPEAN PLATFORM: COMPARATIVE ANALYSIS OF THE PRIPYAT-DNIEPER-DONETS RIFT ZONE AND THE KOLA-ARKHANGELSK PROVINCE

open access: yesГеодинамика и тектонофизика
This paper presents a comparative analysis of geochronological, geochemical, Sr-Nd isotopic data and geodynamic conditions for the Devonian magmatism of the East European Platform, using as an example the Pripyat-Dnieper-Donets rift zone in the south of ...
E. V. Yutkina   +5 more
doaj   +1 more source

Ediacara Obscura: Unveiling Hidden Magnetisations in the Fen Complex, Southern Norway

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 5, May 2026.
Abstract Paleomagnetic directions found in Ediacaran (635–539 Ma) rocks are widely dispersed, which has led to conflicting hypotheses about tectonic regimes and geomagnetic field behavior during this period, and raised doubts about the fidelity of the paleomagnetic record.
Justin A. D. Tonti‐Filippini   +8 more
wiley   +1 more source

Revision of Scheumann’s classification of melilitic lamprophyres and related melilitic rocks in light of new analytical data [PDF]

open access: yes, 2014
Dykes of the Late Cretaceous to Early Tertiary (79.5 ± 3.5 to 60.7 ± 2.4 Ma) melilitic rock series of the Osečná Com- plex and the Devil’s Walls dyke swarm, including ultramafic lamprophyres – polzenites – of Scheumann (1913) occur dispersed in the ...
ADAMOVIČ, J.   +4 more
core   +1 more source

Problems of definition and classification of lamprophyres

open access: yes, 2012
Lamprophyres are mafit to ultramafic porphyritic rocks containing phenocrysts of hydrated mafic minerals, namely dark mica (phlogopite, biotite) and amphibole that are present also in the matrix and commonly are euhedral or nearly euhedral.
Kubínová, Šárka
core   +1 more source

Chemical‐Thermomechanical Modeling of Open‐System Mass Transfer: Application to the Subduction Interface

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 2, February 2026.
Abstract One of the main limitations in simulating subsolidus metasomatism is the decoupling between thermomechanical models and chemical/thermodynamic modeling. This decoupling amplifies the uncertainty associated with mass transport. Here, we introduce a fluid‐rock chemical‐thermomechanical interaction scheme, which integrates thermodynamic modeling (
Jun Ren   +5 more
wiley   +1 more source

MICA COMPOSITION REFLECTING CONDITIONS OF AILLIKITE FORMATION IN ZIMA COMPLEX OF EASTERN SIBERIA

open access: yesГеодинамика и тектонофизика
Four types of mica were identified in the macrocryst and fine porphyry aillikites from the Yarma zone of the Urik-Ija graben considering specific features of morphology, chemical composition, zonation and crystallization conditions.
V. B. Savelyeva   +4 more
doaj   +1 more source

Tectonics, geology and origins of Te Riu‐a‐Māui / Zealandia

open access: yesNew Zealand Journal of Geology and Geophysics, Volume 68, Issue 4, Page 531-567, December 2025.
ABSTRACT Te Riu‐a‐Māui / Zealandia is a 95% submerged, five million square km southern hemisphere continent that includes the islands of New Zealand and New Caledonia. For the last 45 million years (Ma) Zealandia has been cut by the Pacific‐Australian plate boundary which today changes character from a west‐dipping subduction zone in the north to ...
Nick Mortimer
wiley   +1 more source

ALTERATION OF ULTRAMAFIC LAMPROPHYRES AND ITS EFFECT ON RARE EARTH ELEMENT DISTRIBUTION IN THE ILLINOIS-KETUCKY FLUORSPAR DISTRICT [PDF]

open access: yes
The ultramafic lamprophyres of the Illinois-Kentucky Fluorspar District (IKFD) have been identified as a potential domestic source of rare earth elements (REEs).
Walton, Zachary O
core   +1 more source

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