TEM and XRD techniques were used to study crystal growth characteristics of the fabric-forming phyllosilicates which developed in response to low-grade metamorphism and tectonic imbrication in part of the Southern Uplands thrust terrane. Prograde regional metamorphism, ranging from late diagenesis through the anchizone to the epizone, was accompanied by the development of a slaty cleavage which...

Infrared laser probe Ar/Ar geochronology, instrumental neutron activation analysis (INAA) and analytical electron microscopy have been performed on four 0.5 1.0 0.3 cm polished rock tiles of Apollo 16 and 17 granulitic breccias (60035, 77017, 78155, and 79215). Pyroxene thermometry indicates that these samples were re-equilibrated and underwent peak metamorphic sub-solidus recrystallization at ...

The diagenetic history of Triassic sandstone from the Beacon Supergroup, Victoria Land, Antarctica, can be divided into three main phases of shallow burial diagenesis, contact diagenesis (temperatures of 200-300oC), and post-contact diagenesis, on the basis of petrographic and geochemical analyses. Shallow burial diagenesis is characterised by minor compaction, K-feldspar alteration to illite, ...

a brief account of the representative and workable industrial minerals namely magnesite, talc and barite in lesser himalaya, is presented here emphasizing their genesis. deposits of magnesite and talc are found associated with neoproterozoic, plateform type, shelf-slope limestone-dolomite host rocks from inner lesser himalayan sequences. field, textural, geochemical signatures and fluid inclusi...

Abstract Metamorphism of dry, lower crust within orogens is often localized in shear zones composed mechanically weaker rocks 1–4 . Several field-based studies suggest zone development preceded by brittle faults which provide the fluid pathways required for metamorphism and weakening 4–12 However, a unifying model couples long-term geological deformation to migration metamorphic reactions does ...

A brief account of the representative and workable industrial minerals namely magnesite, talc and barite in Lesser Himalaya, is presented here emphasizing their genesis. Deposits of magnesite and talc are found associated with Neoproterozoic, plateform type, shelf-slope limestone-dolomite host rocks from inner Lesser Himalayan sequences. Field, textural, geochemical signatures and fluid inclusi...

Introduction We investigated two processes in a series of the Hungarian L-chondrites: shock and thermal metamorphism. Thermal metamorphism transforms the textures in the relatively small chondritic planetary body. Shock metamorphism is caused by hypervelocity impact processes transforming texture and mineral structure mainly in the outermost layers of the chondritic planetary body [1,2]. The pu...