Search results for "melting"

Garnet as a monitor for melt–rock interaction: Textural, mineralogical, and compositional evidence of partial melting and melt‐driven metasomatism

2021

International audience; In this study, we focus on a partially melted garnet-bearing granulite from the Salvador–Esplanade Belt (Salvador da Bahia, Brazil), and examine the behaviour of major and trace elements during partial melting and melt-driven metasomatism. Phase equilibria modelling and U–Th– Pb geochronology show that the sample underwent partial melting during the heating segment of the decompression path from ~1.2 GPa and 675–700° C to ~0.8 GPa and 790°C at c. 2.06 Ga. During the final stage of decompression, from 0.8 to ~0.5 GPa, physical segregation of melt resulted in the establishment of chemical potential gradients and mass transfer between the host granulite and the leucosom…

Reduction of saturated fat in chocolate by using sunflower oil-hydroxypropyl methylcellulose based oleogels

2021

The suitability of sunflower oil-hydroxypropyl methylcellulose (HPMC) based oleogel obtained by emulsion template approach as partial cocoa butter (CB) replacer in chocolates was investigated. A level of 50% CB replacement was optimum, as higher level of replacement affected the sensory appearance in comparison to the control chocolate (without added oleogel). Four levels of HPMC (0.5, 1, 1.5 and 2%) were considered. Textural and calorimetric properties, as well as sensory properties obtained by Free Choice Profile of the formulated chocolates were investigated. Partial replacement of CB by the sunflower-HPMC based oleogel reduced significantly the chocolate hardness. Higher HPMC concentrat…

Original data and analysis scripts for article: Marked Neurospora crassa strains for competition experiments and Bayesian methods for fitness estimat…

2019

The effect of heat treatment on the morphology and mobility of Au nanoparticles

2020

This work was supported by The Centre National de la Recherche Scientifique (CNRS) of France and the French Embassy Program. The authors are also grateful for partial support by COST Action CA15216, the Estonian Science Foundation (grants PUT1689 and PUT1372), the Estonian Centre of Excellence in Zero Energy and Resource Efficient Smart Buildings and Districts, ZEBE, grant 2014-2020.4.01.15.0016 and Latvian Science Council grant lzp-2018/2-0083.

Heterogeneity of volatile sources along the Halmahera arc, Indonesia

2021

co-auteur étranger; International audience; The parallel Halmahera and Sangihe arcs in eastern Indonesia are sites of active arc-arc collision of considerable interest in developing understanding of the geodynamics and geochemistry of subduction zones. Owing to the comparative remoteness of the region, few ground-based studies of the volcanoes have been undertaken. Here, we report and integrate gas measurements and (isotope) geochemical analyses of lava samples for Dukono, Ibu, Gamkonora, Gamalama, and Makian volcanoes of the Halmahera arc. Summing gas fluxes for all five volcanoes indicates arcscale emission budgets for H 2 O, CO 2 , SO 2 , H 2 S, and H 2 of 96300±27000, 2093±450, 944±400,…

Contribution of magmatism, partial melting buffering and localized crustal thinning on the late Variscan thermal structure of the Agly massif (French…

2020

International audience

New geochemical and combined zircon U–Pb and Lu–Hf isotopic data of orthogneisses in the northern Altyn Tagh, northern margin of the Tibetan plateau:…

2014

Abstract Dunhuang Block is previously considered to be an eastern part of the Tarim Craton, but now it is proposed to be the western extension of the Alxa Block of the NCC as a result of displacement along the Altyn Tagh fault. The oldest basement rocks of the Dunhuang Block, named Aketashitage Complex, were mainly exposed in the northern Altyn Tagh. Migmatites of the Aketashitage Complex are sodic and subalkaline in composition. Zircon U–Pb dating of the tonalitic and monzogranitic migmatites indicates that these rocks were produced by strong deformation of earlier formed tonalites with innumerous granitic veins. The tonalitic melanosome of the migmatites was generated approximately at 2.7…

Zircon REE patterns and geochemical characteristics of Paleoproterozoic anatectic granite in the northern Tarim Craton, NW China: Implications for th…

2012

Abstract Because Archean basement rocks are sparsely distributed around the Tarim Basin, little is known of the relationship between the Tarim Craton and the Paleo- to Mesoproterozoic Columbia supercontinent. Zircon U–Pb dating of a Paleoproterozoic gneissic granite in the northern Tarim Craton yielded a crystallization age of 1915 ± 13 Ma, consistent with global Paleoproterozoic collisional events (ca. 2.1–1.8 Ga) recorded in most cratons. Despite the fact that some zircons display discordant U–Pb ages with a distinct loss of radiogenetic Pb, all grains have similar 176Lu/177Hf and 176Hf/177Hf(t) values. Zircons from this granite have high Th/U ratios (0.15–0.95), but contrasting rare eart…

Generation of early Archaean grey gneisses through melting of older crust in the eastern Kaapvaal craton, southern Africa

2014

Abstract We report zircon ages, Hf-in-zircon isotopes as well as whole-rock geochemistry and Hf–Nd isotopic systematics for Palaeoarchaean grey gneisses of the Ancient Gneiss Complex of Swaziland, the oldest components of the Kaapvaal craton, southern Africa. The Hf-in-zircon isotopic compositions in these compositionally heterogeneous, multicomponent, migmatitic gneisses are highly variable, even in the oldest zircons dating back to 3.66 Ga, suggesting growth of zircon from melts representing a mix of juvenile and anatectic material derived from differentiated continental crust of Eoarchean to late Hadean age. In contrast, the initial Nd and Hf whole-rock isotopic compositions are frequent…

The Othris Ophiolite, Greece: A snapshot of subduction initiation at a mid-ocean ridge

2008

The mantle section of the Tethyan-type Othris Ophiolite, Greece, records tectono-magmatic processes characteristic of both mid-ocean ridges and supra-subduction zones. The Othris Ophiolite is a remnant of the Jurassic Neotethys Ocean, which existed between Eurasia and Gondwanaland. Othris peridotites range from fertile plagioclase lherzolites to depleted harzburgites. Abundances of Al2O3 and CaO show well-defined inverse linear correlations with MgO, suggesting that the Othris peridotites formed as residua from variable degrees of partial melting. Peridotites from the Fournos Kaitsa and western Katachloron sub-massifs are similar to abyssal peridotites and can be explained by a multistage m…