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...

introduction the avan cu-fe skarn is located at the southern margin of qaradagh batholith, about 60 km north of tabriz. the skarn-type metasomatic alteration is the result of qaradagh batholith intrusion into the upper cretaceous impure carbonates. the studied area belongs to the central iranian structural zone. in regional scale, the studied area is a part of the zangezour mineralization zone ...

Humic substances (HS) are redox-active compounds that are ubiquitous in the environment and can serve as electron shuttles during microbial Fe(III) reduction thus reducing a variety of Fe(III) minerals. However, not much is known about redox reactions between HS and the mixed-valent mineral magnetite (Fe3O4) that can potentially lead to changes in Fe(II)/Fe(III) stoichiometry and even dissolve ...

Ž . Although dissimilatory iron reducing bacteria DIRB are capable of reducing a number of metals in oxides and soluble forms, the factors controlling the raterextent of magnetite reduction and the nature of the mineral products resulting from magnetite reduction are not well understood. This study was carried out to investigate mechanisms and biogeochemical processes occurring during magnetite...

Distinct morphological characteristics of magnetite formed intracellularly by magnetic bacteria (magnetosome) are invoked as compelling evidence for biological activity on Earth and possibly on Mars. Crystals of magnetite produced extracellularly by a variety of bacteria including Geobacter metallireducens GS-15, thermophilic bacteria, and psychrotolerant bacteria are, however, traditionally no...

The Jagpura Au-Cu deposit is situated within the Aravalli craton in northwestern part of India. In present work, petrography, mineral chemistry, fluid inclusion and sulfur isotopic compositions were used to study deposit. ore association arsenopyrite, loellingite, chalcopyrite, pyrrhotite pyrite, along with native gold, magnetite apatite. gold fineness ranges from 914–937‰ (avg. 927‰). presence...

Fe isotopes have been applied to the petrogenesis of ore deposits. However, behavior iron in mineralization porphyry-skarn deposits is still poorly understood. In this study, we report mineral separations (magnetite, pyrite, chalcopyrite and pyrrhotite) from two different skarn deposits, i.e., Tonglvshan Cu-Fe deposit developed an oxidized hydrothermal system Anqing Cu a reduced system. both ca...

Diatomite-supported/unsupported magnetite nanoparticles were prepared by co-precipitation and hydrosol methods, and characterized by X-ray diffraction, nitrogen adsorption, elemental analysis, differential scanning calorimetry, transmission electron microscopy and X-ray photoelectron spectroscopy. The average sizes of the unsupported and supported magnetite nanoparticles are around 25 and 15 nm...