Results 31 to 40 of about 1,786 (213)
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
Geostandards and Geoanalytical Research, EarlyView.Key Points Six new Ca‐Mg‐Fe carbonate reference materials are available to the global geochemical community for calibrating oxygen and carbon isotope ratios by SIMS. Significant compositional matrix effects were observed in the dolomite‐ankerite and magnesite‐siderite series during SIMS analysis. Compositional matrix effects correlate with Fe variation.
Maria Rosa Scicchitano +10 more
wiley +1 more source
GeosciencesMafic and ultramafic rocks have become a promising approach for atmospheric carbon dioxide (CO2) reduction, as they are major sources of CO2-reactive minerals, i.e., olivine, pyroxene, plagioclase, and serpentine.
Tadsuda Taksavasu
doaj +1 more source
Geostandards and Geoanalytical Research, EarlyView.Key Points A new magnetite reference material (PF21mt) is available for δ18O measurements by SIMS. Reproducibility of measurement results in two laboratories suggest orientation bias of ±2‰ (2s) at 20 keV. Repeatability improves to ±1‰ (2s) when using a 13 keV protocol, suggesting reduced orientation bias. In situ isotope ratio measurements provide the
Michelle Ulrich +4 more
wiley +1 more source
Multi-stage serpentinization of ultramafic rocks in the Manlay Ophiolite, southern Mongolia
Mongolian Geoscientist, 2021 Serpentinization of ultramafic rocks in ophiolites is key to understanding the global cycle of elements and changes in the physical properties of lithospheric mantle.
Amarbayar Nomuulin +6 more
doaj +1 more source
Interplay Between Mechanical and Petrochemical Models on the Fluid Extraction From Subduction Zones
Journal of Metamorphic Geology, EarlyView.ABSTRACT The breakdown of hydrous minerals during subduction results in a densification of the rocks, producing volume changes that can trigger fluid pressure fluctuations and hydrofracturing. These volume changes are controlled by the Clapeyron slope of the reaction and are quantified here using a macroscopic framework that integrates a zero ...
Thorsten Andreas Markmann +1 more
wiley +1 more source
Plagioclasites from chromite-bearing ultramafic rocks of the Rai-Iz massif
Литосфера, 2016 The corundum-bearing and without-corundum plagioclasites from chromite-bearing ultramafic rocks of Rai-Iz massif were studied. Chemical composition of the rock-forming minerals and rock geochemical characteristics was determined.
N. V. Vakhrusheva +6 more
doaj +2 more sources
Terra Nova, EarlyView.ABSTRACT Deep crustal fragments and structural lineaments identified through satellite gravity data provide evidence for the extension of the reworked ancient basement of the Central African Block into the northern São Francisco Craton and southern Borborema Province.
Douglas Teixeira Martins +3 more
wiley +1 more source
Applied Sciences, 2020 This article describes the screening, ranking and characterization of ultramafic and mafic rocks in southern Portugal for mineral carbonation as an alternative to conventional CO2 storage in sedimentary rocks.
Jorge Pedro +7 more
doaj +1 more source
Terra Nova, EarlyView.ABSTRACT The Transbrasiliano‐Kandi‐4°50′ (TK4) shear zone in western Gondwana crosscuts South America and NW Africa for at least 6000 km. Despite its impressive size, the timing of the main episode of dextral ductile shearing is uncertain. We present detailed in situ multi‐mineral geochronology of mylonites from both Brazil and Algeria supporting that ...
F. A. Caxito +4 more
wiley +1 more source