Results 51 to 60 of about 4,150 (216)
Geochemistry, Geophysics, Geosystems, 2021 Melt inclusions with large, positive Sr anomalies have been described in multiple tectonic settings, and the origins of this unusual geochemical feature are debated.
O. E. Anderson +7 more
doaj +1 more source
Geological Journal, EarlyView.Charnockites with 2691–2607 Ma magmatic ages from the NMZ show arc‐magmatic geochemical signatures. They correspond to the lower‐crustal equivalent of the Chilimanzi Suite Granite in the Zimbabwe Craton. Lu‐Hf isotopic data of magmatic zircons show negative εHf(t) values (−11.18 to −2.20) with TDMC ages of 3699–3158 Ma, suggesting their protolith ...
Toshiaki Tsunogae +6 more
wiley +1 more source
Elasticity of plagioclase feldspars [PDF]
Journal of Geophysical Research: Solid Earth, 2016 AbstractElastic properties are reported for eight plagioclase feldspars that span compositions from albite (NaSi3AlO8) to anorthite (CaSi2Al2O8). Surface acoustic wave velocities measured using Impulsive Stimulated Light Scattering and compliance sums from high‐pressure X‐ray compression studies accurately determine all 21 components of the elasticity ...
J. Michael Brown +3 more
openaire +2 more sources
High‐Titanium Zircon Rims in Rhyolite – A Reflection of Adiabatic Ascent?
Geological Journal, EarlyView.The ascent of granitic magma from source to emplacement is rapidly achieved through dyking, resulting in negligible heat loss to the surrounding wallrock (i.e., adiabatic). Zircon growth during ascent can record the changing magma conditions including adiabatic cooling and heating, resulting in high titanium rims on low titanium cores without ...
Carson Kinney +2 more
wiley +1 more source
Geochemistry, Geophysics, Geosystems, 2022 Plagioclase ultraphyric basalts (PUBs) are a class of mid‐ocean ridge (MOR) lavas found in a variety of ocean floor environments, are characterized by abundant (15–40 volume %) plagioclase megacrysts and a diverse trace element and isotopic signature ...
Gokce K. Ustunisik +2 more
doaj +1 more source
Notable Impact of Paleotectonic Stress on Gold Mineralisation in the West Qinling Orogen
Geological Journal, EarlyView.By applying fuzzy clustering and multiple inverse methods, we systematically processed the data of vein and fault slip in this ore deposit to reveal the transition of orogenic geological environment and paleotectonic stress field. Our research results show two different stress states: the northwest–southeast extensional stress field and the northeast ...
Hongyan Wang +3 more
wiley +1 more source
Plagioclase as evidence of magmatic evolution in the Zafarqand porphyry copper deposit, NE Isfahan
Journal of Economic Geology, 2018 Introduction Chemical and textural zoning patterns preserved in plagioclase phenocrysts can provide useful information on parameters that constrains the changing melt compositions in the magma systems.
Maryam Aminoroayaei Yamini +3 more
doaj +1 more source
Syn-kinematic hydration reactions, grain size reduction, and dissolution–precipitation creep in experimentally deformed plagioclase–pyroxene mixtures [PDF]
Solid Earth, 2018 It is widely observed that mafic rocks are able to accommodate high strains by viscous flow. Yet, a number of questions concerning the exact nature of the involved deformation mechanisms continue to be debated.
S. Marti +5 more
doaj +1 more source
Archaeometry, EarlyView.Abstract Kohl was ubiquitous in ancient Egypt and the Middle East, and routinely included among the toiletries deposited in burials. For Egypt, kohl recipes are increasingly well‐studied and known to use a range of inorganic and organic ingredients. Although these are often lead‐based, manganese‐ and silicon‐rich compounds are also attested.
Silvia Amicone +7 more
wiley +1 more source
Archaeometry, EarlyView.Abstract Soils that contain swelling clay minerals (e.g., montmorillonite) expand and contract during wetting and drying, causing movement within the soil profile. This process, known as argilliturbation, can alter artefact distributions, destroy stratigraphy and complicate the interpretation of archaeological deposits.
Caroline Mather +11 more
wiley +1 more source