Results 61 to 70 of about 4,348 (222)

APG2: a New Version of APG, an Application for Amphibole-Plagioclase Geothermobarometry [PDF]

open access: yesJournal of Sciences, Islamic Republic of Iran, 2016
APG2 is a computer application designed for amphibole-plagioclase geothermobarometry. It is the first updated version of APG and supports 4 thermometer models and 6 barometer models involving either amphibole-plagioclase or amphibole only.
M. Sayari
doaj  

Dispersal, source and glass chemistry of a third tephra unit within Iceland's Settlement Layer

open access: yesBoreas, EarlyView.
Tephra layers may be studied to understand the dynamics and sequence of past explosive volcanism. In Iceland, the distinctive Settlement Layer (AD ~877) underlies almost all archaeological evidence for the Norse Settlement and is preserved in soils across Iceland and as cryptotephra overseas.
Conner A. G. Morison   +3 more
wiley   +1 more source

Influence of Laser Repetition Rate, Fluence and Spot Size on LA‐Q‐ICP‐MS/MS 87Sr/86Sr Precision: Insights from Apatites and Silicate Glasses

open access: yesGeostandards and Geoanalytical Research, EarlyView.
Key Points Higher laser repetition rate, fluence and larger spot size increase signal intensity. Higher laser repetition rate produces overlaps in aerosolised particles, improving signal stability and precision. For Sr‐rich materials, moderate spot diameter (≤ 60 μm), 3 J cm‐2 fluence and ≥ 12 Hz repetition rate are recommended.
Edafe O. Ominigbo   +4 more
wiley   +1 more source

(Ultra)high‐Pressure Metamorphism in Sedimentary Versus Basaltic Rocks: Insights From a Variscan Mélange in the South Carpathians

open access: yesJournal of Metamorphic Geology, EarlyView.
ABSTRACT Reconstructing the pressure–temperature–time (P–T–t) evolution of (ultra)high‐pressure rocks is essential for constraining subduction and collisional dynamics. Subduction zones are often investigated using basic eclogites, whereas nonbasic high‐pressure rocks remain comparatively understudied, potentially hindering a comprehensive ...
Otavio S. G. Silva   +7 more
wiley   +1 more source

Petrogenesis of Plagioclase Ultraphyric Basalts (PUB) From the Northeastern (NE) Pacific Ridge System: Evidence From Mineral Textures and Geochemical Characteristics

open access: yesGeochemistry, Geophysics, Geosystems
Plagioclase crystals in plagioclase ultraphyric basalts (PUB) record changes in the major, trace, and isotopic compositions of evolving magmas. Those changes represent the record of specific processes in the crust and upper mantle that impart distinct ...
John B. Hewitt   +2 more
doaj   +1 more source

Feldspar Albitization With Implications for Reservoir Quality Evolution of Eocene Turbidite Sandstones in Offshore Espírito Santo Basin, Eastern Brazil

open access: yesJournal of Petroleum Geology, EarlyView.
ABSTRACT The diagenetic albitization of plagioclase and K‐feldspar grains is a transformative process that significantly alters sandstone's detrital composition and formation water chemistry, impacting reservoir quality. In this study, Eocene turbidite sandstones from the offshore Espírito Santo Basin, Brazil, were investigated to elucidate the role of
Eveline E. Zambonato   +2 more
wiley   +1 more source

Mineral associations in the rocks and metamorphism conditions of the Kandalaksha gabbro-anorthosite massif (Kola Peninsula)

open access: yesЛитосфера, 2016
The composition of mineral associations was studied in the main varieties of the rocks within the metamorphosed Kandalaksha gabbro-anorthosite massif in the southern part of the Kola Peninsula.
V. V. Chashchin   +4 more
doaj   +2 more sources

Insights into the magma plumbing system architecture beneath an off-ridge ocean island (Terceira, Azores) from crystal zoning

open access: yesVolcanica
Understanding the architecture and dynamics of crustal magmatic plumbing systems is essential for interpreting volcanic processes and eruption styles in ocean island settings.
Kat Shepherd   +10 more
doaj   +1 more source

LifeMet: Report on the 2024–2025 meteorite recovery expedition in Dronning Maud Land, Antarctica for the study of microbe–meteorite interactions

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Since the discovery of nine meteorites near the Yamato mountains in 1969, Antarctica has been recognized as a superb location for meteorite recovery. While Antarctic recovery expeditions prioritize meteorite preservation for mineralogical and planetary studies, meteorites are not typically collected for biological applications.
Rachael Lappan   +2 more
wiley   +1 more source

Stardust Mine: A 2024 gabbroic shergottite from Arizona, USA

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract This study provides an initial characterization of Stardust Mine, a fresh gabbroic enriched shergottite collected in Arizona, USA, in September 2024 and is the first Martian meteorite to be unequivocably collected on US soil. Analysis was conducted on the type specimen and finds that Stardust Mine is composed of equal proportions of pyroxene ...
Jennifer T. Mitchell   +4 more
wiley   +1 more source

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