The granulite facies assemblages of the anorthositic rocks of the Bergen Arcs (stable at 800 -900°C and 10 kbar) have been transformed to eclogite facies assemblages (stable at 700 -750°C and 16-19 kbar) in the vicinity of Caledonian shear zones. This section of the root zone of the Caledonian mountain chain reveals a deep polymetamorphic crust where Precambrian granulites (mean density 3.02 g ...

Integrated metamorphic and geochronological data place new constraints on the metamorphic evolution of a Neoproterozoic orogen in east Antarctica. Granulite-facies rocks from a 150 km stretch of the Kemp Land coast reflect peak conditions involving T 870^9908C at P 7 4^10 kbar, with pressure increasing westward towards an Archaean craton. Electron microprobe-derived (ThþU)^Pb monazite ages from...

Abstract Amphibole‐rich rocks constitute significant components of the mid‐ to lower continental crust, particularly in active orogens characterized with thick and hot crusts. Nevertheless, experimental data on their viscosity remain scarce. We conducted axial compression deformation experiments synthetic amphibolites under temperature pressure conditions resembling deep sections overthickened ...

The Lindås Nappe, Bergen Arc, is located in western Norway and displays two high-grade metamorphic structures. A Precambrian granulite facies foliation is transected by Caledonian fluid-induced eclogite-facies shear zones and pseudotachylytes. To understand how a superimposed tectonic event may influence olivine fabric and change seismic anisotropy, two lenses of spinel lherzolite were studied ...

The lower crust beneath the North China Craton (NCC) was transformed during craton destruction in Mesozoic, however, transformation processes are yet to be fully understood. Compositional and geochronological variations of granulite pyroxenite xenoliths provided insights into nature before after destruction. In this study, we summarized latest results geochemistry zircon geochronology coupled w...

Graphite deposits may form alternatively by metamorphism of sedimentary rocks and from fluids. Both types occur in supracrustal successions within the Lewisian Complex Northwest Scotland, similarly Palaeoproterozoic across North Atlantic region Canada, Greenland Scandinavia. Carbon isotope compositions show that graphite Scotland had a mixed origin organic matter (schists) decarbonation limesto...