The Eoarchean Isua supracrustal belt (ISB) has been interpreted as one of the earliest records subduction processes, leading to conclusion that a plate tectonic geodynamic system was likely operating since early Archean. However, proposed models remain difficult evaluate our understanding metamorphic and structural evolution remains fragmentary. Here, we present study rocks ISB. We used petrogr...

Abstract A careful petrologic analysis of mylonites’ mineral assemblages is crucial for a thorough comprehension the rheologic behaviour ductile shear zones active during an orogenesis. In this view, understanding way new minerals form in rocks sheared manner and why relict porphyroblasts are preserved where reactions generally supposed to be deformation-assisted, essential. To goal, role chemi...

The giant planet atmospheres exhibit alternating prograde (eastward) and retrograde (westward) jets of different speeds and widths, with an equatorial jet that is prograde on Jupiter and Saturn and retrograde on Uranus and Neptune. The jets are variously thought to be driven by differential radiative heating of the upper atmosphere or by intrinsic heat fluxes emanating from the deep interior. H...

This paper is a complement to the Tectonometamorphic Map of the Canadian Shield, and contains a brief description of the metamorphic history of Proterozoic orogenic belts and rock sequences in the Canadian Shield in Ontario, with a focus on rocks of the Southern and Grenville provinces. Metamorphism in the Southern Province has generally been attributed to the Penokean orogeny (~1879–1820 Ma), ...

Abstract Precambrian greenstone belts are prospective terrains for orogenic Au deposits worldwide, but the sources of Au, base metals, metalloids, and ligands enriched within still debated. Metamorphic devolatilization is a key mechanism generating Au-rich hydrothermal fluids, respective role metavolcanic metasedimentary rocks present these in releasing ore-forming elements not fully understood...

Here, we study slate microfabrics from the exhumed accretionary wedge of central European Alps and focus on development foliation. High-resolution micrographs novel BIB-SEM imaging Synchrotron X-ray Fluorescence Microscopy are analysed with 2D auto-correlation functions to quantify geometry spacing along a metamorphic gradient covering outer inner (200–330 °C). The sedimentary layering primaril...

Field observations within the Atg-serpentinite domain of subducted ultramafic massif from Cerro del Almirez (SE Spain) reveal existence two generations abundant olivine-rich veins formed as open, mixed mode and shear fractures during prograde metamorphism. Type I were synchronous with development serpentinite main foliation (S 1 ) shearing, whereas II post-date S surfaces. These structural rela...

Zoned, silica-deficient, calcic garnets containing up to 5 mol% F substitution for 0 formed during contact metamorphism of basalts by the Skaergaard intrusion in East Greenland. Fluorian calcic garnets occur as a retrograde alteration of prograde wollastonite and clinopyroxene that fills vesicles and vugs in lavas 30-70 m from the intrusion. Paragenetically equivalent phases include fluorite, w...