Results 21 to 30 of about 4,150 (216)

Rapakivi texture in porphyritic dikes within the Karavanke granitic massif (Slovenia) [PDF]

open access: yesBulletin of the Geological Society of Finland, 2002
The northern Karavanke Granitic Massif straddles the Slovenian–Austrian border. The investigated area lies in northern Slovenia, and extends from the western Slovenian–Austrian border to the east for about 30 km, with a maximum width of 2 km.
M. Dobnikar, T. Dolenec, G. Bellieni
doaj   +1 more source

A History of Andesite Production via Magma Mixing and Mingling Revealed Microscopically at Ngauruhoe Volcano

open access: yesGeochemistry, Geophysics, Geosystems, 2022
Many andesites erupted at arc volcanoes are the products of magma mixing, and this process could be important in triggering their eruption. Throughout the life of Ngauruhoe volcano (∼2.5 ka), erupted andesites lack macroscopic enclaves or lithological ...
Kate Cocker   +4 more
doaj   +1 more source

Theoretical Models of Decompression-Induced Plagioclase Nucleation and Growth in Hydrated Silica-Rich Melts

open access: yesFrontiers in Earth Science, 2020
Magma ascending from the storage region toward the surface may crystallize small and rapidly-grown crystals, designated as microlites. Upon decompression, the rapid changes of the microlite textures, such as number density and crystal size, directly ...
Edith Mollard   +3 more
doaj   +1 more source

Features of olivine crystallization in ordinary chondrites (Saratov meteorite): geochemistry of trace and rare earth elements

open access: yesЗаписки Горного института, 2022
The paper discusses the geochemistry of major (EPMA) and trace (SIMS) elements in olivine of porphyritic, nonporphyritic chondrules, and the matrix of equilibrated ordinary chondrite Saratov (L4).
Kristina G. Sukhanova   +2 more
doaj   +1 more source

Partitioning of barium between coexisting K-feldspars and plagioclase in the Bushveld granites from the Zaaiplaats area, South Africa [PDF]

open access: yesBulletin of the Geological Society of Finland, 1984
The barium contents of the coexisting K-feldspars and plagioclases in the Bushveld granites from the Zaaiplaats tin mine area were determined by electron microprobe analyses.
J.T. Ollila
doaj   +1 more source

Trace Element and Isotopic Characteristics of Plagioclase Megacrysts in Plagioclase Ultraphyric Basalts (PUB)

open access: yesGeochemistry, Geophysics, Geosystems, 2020
Major, trace, and isotopic compositions of plagioclase megacrysts from plagioclase ultraphyric basalts (PUB) from multiple mid‐ocean ridges were determined to characterize the liquid compositions from which they were derived.
Roger L. Nielsen   +4 more
doaj   +1 more source

Physical Conditions of the Formation of Plagioclase Crystals Using Crystal Size Dispersion (CSD) in the Mafic Migmatites of Northeastern Takab

open access: yesJournal of Economic Geology, 2023
The Zanjan-Takab complex is a metamorphic belt with NW-SE trend that includes gneiss, amphibolite and gneissic amphibolite, old metagranites, pelitic schists with migmatites and metaophiolites.
Haleh Ghorbani   +2 more
doaj   +1 more source

APG: An Efficient Software Program for Amp-Pl Thermobarometry Based on Graphical Method [PDF]

open access: yesJournal of Sciences, Islamic Republic of Iran, 2011
Geothermobarometry equations are based on thermodynamic principles and appear in single or multi-variant functions. The number of variants for a specific composition or reaction usually is reduced into 2 involving temperature (T) and pressure (P).
M. Sayari
doaj  

Experimental Constraints on Homogenization of Plagioclase-Hosted Melt Inclusions From Plagioclase Ultraphyric Basalts

open access: yesFrontiers in Earth Science, 2021
Study of melt inclusions (MIs) is a commonly applied method for defining the composition of magmas present at depth prior to mixing, fractionation, and degassing. Our ability to use data from MIs is complicated by post-entrapment processes (PEP) that can
Kristen R. Lewis   +4 more
doaj   +1 more source

Microscopic time‐dependent mechanical behavior of shale derived from nanoindentation

open access: yesDeep Underground Science and Engineering, EarlyView.
This study conducted grid nanoindentation creep tests to systematically analyze the microscopic creep behaviors of shale. Based on the analysis of creep strain rate sensitivity, the primary mechanism of microscopic creep in shale was found to be the extension and closure of microcracks.
Cunbao Li   +4 more
wiley   +1 more source

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