Serpentinite-hosted massive magnetite ore bodies are reported for the first time in Late Cretaceous Sabzevar ophiolitic belt, northeastern Iran. They show irregular and discontinuous shapes with variable sizes ranging from 30 to 60 cm. Chromian spinel grains observed within both ores host serpentinite. Magmatic chromian spinels, (Cr,Al)-spinel I, compositions close (Mg0.6,Fe0.4)(Cr1.2,Al0.75,Fe...

the formation of atoll garnet in hornblende schists from the contact aureole of mashhad granite,ne iran, is discussed using textural and chemical data. these data suggest the possibility of incipientreplacement of pre-existing idioblastic garnet from the core. in addition, the presence of chlorite and calcite inthe core of atoll garnet reveal the retrograde nature of atoll formation.

Abstract Several swarms of parallel E–W dikes cuts late Neoproterozoic- to early Paleozoic (540 Ma) basement in the Biarjmand area, NE Iran. The microgabbroic doleritic dike are several hundred meters long and 0.5 3 wide. U–Pb dating their zircon grains yields a crystallization age 46.0 ± 7.1 Ma for swarms. have SiO2 contents 46.0–49.3 wt%, Fe2O3 9.80–14.8 wt% with variable MgO (4.92–9.16 wt%),...

This paper introduces the concept of a dynamic key infrastructure for Grid. It utilises the properties of Identity-based Cryptography (IBC) to simplify key management techniques used in current Public Key Infrastructure (PKI) settings for Grid. This approach can offer greater simplicity, flexibility, and enhanced computation trade-offs.

the sofeh mountain in the south of isfahan (iran) has a development of shafts (vertical cave). simorgh cave with a depth of 42 m and a length of 52 m has developed along significant fault structures. structural analysis indicates relationships of orientation between the faults and fractures and shafts and chambers geometries. considering the main ne-sw trend of tectonic structures in the area, ...