The Himalayan range exposes a spectacular assemblage of metamorphic rocks from the midand deep crust that have fostered numerous models of how the crust responds to continental collisions. Recent petrogenetically based petrologic and geochronologic studies elucidate processes with unprecedented resolution and critically test models that range from continuum processes to one-time events. The pro...

Ion microprobe analysis with a sub-micrometer diameter spot reveals a sharp, 2 μm gradient in oxygen isotope ratio proving that oxygen diffusion in zircon is slow even under prolonged high-grade metamorphism. The data are consistent with an oxygen diffusion coefÞ cient of 10–23.5±1 cm2/s. Furthermore, this gradient is found in a zircon that contains clear textural evidence of recrystallization ...

Shock metamorphism in chondritic parent bodies produces typical textures, visible under the microscope, which are a consequence of structural deformation of the crystals. Such deformations can be studied with Raman spectroscopy. The vibrational characteristics of olivines and pyroxenes, structurally deformed by weak-to-moderate shock metamorphism, have been determined on four Spanish ordinary c...

Introduction: CK carbonaceous chondrites are the only group of carbonaceous chondrites that exhibit thermal metamorphism. As a result, CKs display features of metamorphism such as silicate darkening, recrystallization and shock veins. Calcium Aluminum Inclusions and Fe-Ni metal are rare. Type Chondrule Opaque CAI's Matrix MET01149,11 3 25.0 7.0 2.0 66.0 EET99430,5 4 5.1 3.5 4.7 86.7 QUE99679,7 ...

The central part of the Qilian orogenic belt (QOB) on NE Tibetan Plateau is known as Central Block (CQB), and research deformation metamorphism CQB improves our understanding tectonic evolution QOB, which makes up an important continental crust in eastern Asia. Here we present results thermobarometric calculation geochronological analyses for deformed metamorphic rocks northern margin CQB, thes...