Results 51 to 60 of about 5,319 (257)

Amphibole and biotite of melanocratic rocks from the Ural granitic massifs: composition, relationship, petrogenetic consequences

open access: yesЛитосфера, 2020
Research subject. The article discusses the features of the relationship between biotite and amphibole on the example of magmatogene melanocratic rocks from a number of granitoid massifs of the Urals. These rocks form xenoliths and synplutonic intrusions
S. V. Pribavkin
doaj   +1 more source

Application of Clinopyroxene Chemistry for Investigation of the physical conditions of ascending magma, a case study of volcanic rocks in the Aliabad area (Northwest of Nain)

open access: yesJournal of Economic Geology, 2020
Introduction The Aliabad area is located in the northwest of Nain. Volcanic rocks of the Aliabad area have andesitic to rhyolitic composition. On the basis of petrographic investigations, porphyritic texture is the main texture of these rocks.
Rezvan Mehvari, Mortaza Sharifi
doaj   +1 more source

Olivine‐Ahrensite Phase Relations in the Mg2SiO4‐Fe2SiO4 System as a Function of Temperature

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 1, January 2026.
Abstract Olivine and ahrensite are the primary components of the interiors of Fe‐rich terrestrial planets and meteorites, making their phase relations crucial for planetary science. Moreover, their phase relations can be used for calibrating large‐volume high‐pressure devices such as multi‐anvil apparatus.
Artem Chanyshev   +12 more
wiley   +1 more source

Petrography, geochemistry and mineral chemistry of the Almogholagh intrusive rocks (Hamedan, Iran): Evidences for their shallow-level emplacement [PDF]

open access: yesپترولوژی, 2018
The Almogholagh plutonic body with about 10 km2 is located 15 km of West of Hamedan city and on the Sanandaj-Sirjan zone. The Almogholagh pluton consists of diorite and gabbroic diorite, monzodiorite, quartz monzodiorite, monzonite, quartz monzonite ...
Hossein Shahbazi   +6 more
doaj   +1 more source

An Inverse Method for Quantifying Petrological Parameters and Uncertainty in Phase Equilibrium Modelling

open access: yesJournal of Metamorphic Geology, Volume 44, Issue 1, Page 70-84, January 2026.
ABSTRACT Phase equilibrium modelling offers a powerful quantitative framework for understanding petrological processes. Yet, many studies still rely on qualitative comparisons between natural datasets and these forward modelled predictions to constrain model parameters, commonly pressure–temperature (P–T) conditions.
T. Mackay‐Champion, I. P. Cawood
wiley   +1 more source

Temporal variations in storage conditions of the post-collapse rhyolites, Valles Caldera, New Mexico (USA)

open access: yesVolcanica
We present a petrologic study of the post-collapse rhyolites from Valles Caldera (New Mexico, USA) to evaluate changes in magmatic storage conditions following the eruption of the Upper Bandelier Tuff (UBT). We assess likely phenocrysts through textures,
Magdalen Grismer, Laura Waters
doaj   +1 more source

Elastic-thermobarometry: methods and applications to ultrahigh pressure metamorphic rocks

open access: yesPlinius, 2020
Ultra-High Pressure (UHP) metamorphic rocks represent the evidence we have for the detailed reconstruction of tectonic processes, which are the source of major natural hazards like deep-focus earthquakes and volcanic eruptions. Mineral inclusions are often the only proof of ultrahigh pressure metamorphism and their study provides insights into the ...
openaire   +2 more sources

P–T paths reconstruction of a collisional event: The example of the Thiviers-Payzac Unit in the Variscan French Massif Central [PDF]

open access: yes, 2007
International audienceBecause of late metamorphic and tectonic overprints, the reconstruction of prograde parts of P–T paths is often difficult. In the SW Variscan French Massif Central, the Thiviers-Payzac Unit (TPU) is the uppermost allochthon emplaced
Duguet, Manuel   +2 more
core   +3 more sources

Textural and geochemical diversity of impact melt rock clasts in Apollo 16 sample 67015: Implications for the provenance of impact ejecta in the lunar highlands

open access: yesMeteoritics &Planetary Science, Volume 61, Issue 1, Page 39-63, January 2026.
Abstract Apollo sample 67015 has been classified as a fragmental breccia comprised of highlands‐type clasts and is proposed to be the most complex Apollo 16 sample. 67015 is dominated by impact melt rock clasts that display a variety of textures, which have been previously interpreted to be indicative of multiple impact events.
Tara S. Hayden, Gordon R. Osinski
wiley   +1 more source

Mineral chemistry and geothermobarometry of metabasites of the Majerad igneous-metamorphic complex (SE of Shahrood)

open access: yesJournal of Economic Geology, 2020
Introduction Thermobarometric models based on the chemical equilibrium among coexisting mineral-mineral or mineral-melts pairs are useful tools widely used to estimate the P-T path and chemical evolution during igneous processes. The high sensitivity of
Marzieh Veiskarami   +3 more
doaj   +1 more source

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