background: the concentrations of radionuclides like 226ra, 232th and 40k and the dose rate are measured in igneous and metamorphic rock formations in and around chickmagalur. a total of 236 samples from 13 different locations around study area were analyzed. materials and methods: the activity concentrations of the three radioactive elements were determined for mean period of 25000 s using hpg...

kuh-e-faryadoon and kouli kosh iron deposits are hosted by regional metamorphic rocks of sanandaj-sirjan zone around deh-bid area. plugs and domes of acid rocks protrude these metamorphic rocks. a mylonitization event is super imposed on acid rock and metamorphic complexes. field, petrological and geochemical studies have shown that (1) iron mineralization have occurred during mylonitization in...

INTRODUCTION The redox state of sillimanite zone (650–700°C, 5–6 kbar) metasediments of the Barrovian type area, Scotland, was investigated The chemical and mineralogical evolution of the crust using estimates of metamorphic oxygen fugacity (fO2 ), sulfur fugacity during orogenesis is critically dependent upon the redox (fS2 ), and fluid chemistry based on new determinations of mineral state of...

Kuh-E-Faryadoon and Kouli Kosh iron deposits are hosted by regional metamorphic rocks of Sanandaj-Sirjan zone around Deh-Bid area. Plugs and domes of acid rocks protrude these metamorphic rocks. A mylonitization event is super imposed on acid rock and metamorphic complexes. Field, petrological and geochemical studies have shown that (1) Iron mineralization have occurred during mylonitization in...

A recurring challenge to ion microprobe U^Pb zircon geochronology has been to discriminate between preservation of original igneous zircon populations and inherited grains. This has proved particularly problematic in studying the polyphase metamorphic rocks that dominate Early Archean gneissic terranes. For example, differing interpretations exist for the origin of complex zircon populations in...

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 ...