The N/NNE-striking Aravalli Delhi Fold Belt (ADFB) and the E-striking Central Indian Tectonic Zone (CITZ) converge at Godhra-Chhota Udepur (GC) sector, west-central India. Analyses of mesoscale deformation structures metamorphic phase equilibria in basement supracrustal rocks are integrated with geochronological-geochemical data (accompanying article) to address dynamics Early Neoproterozoic CI...

The high-silica sericites generally contain a corresponding appreciable quantity of a divalent element, usually magnesium, and their chemical composition is interpreted as being intermediate between that of muscovite, KA12 (A1Sia)O10(OH)2, and that of the equivalent high-silica mica leucophyllite, KAIMg (Si4)O10(0H)2. The series muscovite-leucophyl]ite includes the named micas phengite (high-si...

The Arosa Zone, Central Alps, represents a Cretaceous to Paleogene fossil subduction interface from paleodepths of 10 >35 km. Metasedimentary schists directly below preserved seismogenic zone exhibit viscous (foliations, folds, and lineations) brittle (crack-seal quartz ± calcite veins) deformation features. Si-in-phengite barometry published temperature estimates yield metamorphism conditions ...

Phase diagrams of hydrous mid-ocean ridge (MOR) basalts to 330 km depth and of hydrous peridotites to 250 km depth are compiled for conditions characteristic for subduction zones. A synthesis of our experimentally determined phase relations of chlorite, lawsonite, epidote-zoisite, amphibole, paragonite, chloritoid, talc, and phengite in basalts and of phase relations from the literature of serp...

The Alpi Apuane (northern Apennines) represent a key area for understanding the processes related to Apennines building and geodynamic evolution of central Mediterranean, but timing tectono-metamorphic events is still debated. White mica from cover rocks Massa units was investigated by 40Ar-39Ar in situ step-heating techniques. Samples recorded several episodes deformation developed under low-g...

Eclogites from the Guanshan and Yangkou areas of Sulu orogen consist garnet, omphacite, phengite, amphibole, quartz/coesite, rutile, ilmenite. Garnet exhibits weak compositional zoning where Xgr decreases core to mantle then increases towards rim, coupled with an increase in Xpy decrease rim. Phase equilibria modelling pseudosections calculated using THERMOCALC NCKFMASHTO system for eclogites r...