Ultrasonic laboratory measurements of seismic compressional velocities (Vp) carried out on rock samples encompasing a wide range of metamorphic grades and lithologies from the Betic chain are presented. Measurements were performed at a high confining pressure on a total of 12 representative samples of the Alboran Domain (Internal Betics). P-wave mean velocities, referred to pressure conditions ...

chloritoid is crystallised with chlorite, white mica and garnet in chlorite zone metapelites ofthe regional metamorphic rocks of the sanandaj-sirjan metamorphic belt in southern iran. chemistry ofcoexisting minerals is studied using microprobe analysis. application of the chlorite-chloritoidgeothermometry gives temperatures of 515°c and 557°c. the chlorite-garnet fe-mg exchangegeothermometer in...

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...

Based on lithological, structural and geophysical characteristics, the Proterozoic Grenville Orogen of southern Ontario and New York has been divided into domains that are separated from each other by ductile shear zones. In order to constrain the timing of metamorphism, U-Pb ages were determined on metamorphic and igneous sphenes from marbles, calc-silicate gneisses, amphibolites, granitoids, ...

Monazite-(Ce) and xenotime-(Y) were found in the metacherts (pumpellyite–actinolite-facies conditions: 3 ≤ P ≤ 4 kbars and 300 ≤ T ≤ 350°C) of the Monte Figogna Unit, Sestri–Voltaggio Zone, Liguria, in Italy, as scattered submillimetric grains in pelitic beds and as euhedral crystals in both millimeter-thick quartz veins and open fissures. Their composition is comparable to those of known occur...