introduction more than 30 fluorite occurrences with approximately 1.35 million tons of reserves have been recognized in iran (ghorbani, 2013). the atashkuh fluorite-barite (±sulfide) deposit is one of four occurrences located south of the city of delijan in markazi province, about 80 km se of arak city. the atashkuh deposit occurs between the central iran structural zone on the north and the sa...

molybdenite occurs in five forms in the sar cheshmeh porphyry copper deposit, namely, (1)-veinlets with quartz-molybdenite, (2)-veinlets with quartz-molydenite that were filled with pyrite, (3)-veinlets with quartz-molybdenite-pyrite–chalcopyrite, (4)-molybdenite veinlets with very low quartz and (5)-disseminated molybdenite grains. because of their large size, the veinlet-related molybdenite g...

OBJECTIVES Little information is available on the quantitative risks of respiratory disease from quartz in airborne dust in the heavy clay industry. Available evidence suggested that these risks might be low, possibly because of the presence in the dust of other minerals, such as illite and kaolinite, which may reduce the harmful effects of quartz. The aims of the present cross sectional study ...

Introduction: Research into the origin of color of common varieties of quartz has shown that many longheld beliefs regarding the origin of the colored varieties are incorrect. In particular, the widely stated role of rutile inclusions in the coloration of rose and blue quartz must now be re-evaluated on the basis of new studies. Rose Quartz: Spectroscopic studies have shown that the color of ro...

A new model accounts for crystal growth patterns and internal textures in quartz cement in sandstone fractures, including massive sealing deposits, thin rinds or veneers that line open fracture surfaces, and bridge structures that span otherwise open fractures. High-resolution cathodoluminescence imaging of bridge structures and massive sealing deposits indicates that they form in association w...

The paper presents the latest state of knowledge on clastic sedimentary rocks from Carboniferous complex in SW part Polish Lowlands, studied to help determine their potential prospectivity for occurrence oil and/or gas deposits. Rocks were analyzed with respect petrographic-mineralogical characteristics deposits, diagenesis, determinations pressure-temperature conditions mineral formation and h...

A detailed oxygen isotope study of detrital quartz and authigenic quartz overgrowths from shallowly buried (<1 km) quartz arenites of the St. Peter Sandstone (in SW Wisconsin) constrains temperature and fluid sources during diagenesis. Quartz overgrowths are syntaxial (optically continuous) and show complex luminescent zonation by cathodoluminescence. Detrital quartz grains were separated from ...

Autonomous navigation systems are important to Military Operations on Urbanized Terrain (MOUT) simulations for generating realistic tactical behaviours for the non-player characters (or bots). In this paper, we describe our work on Quartz, an autonomous navigation system for MOUT simulations. Novel features of Quartz include qualitative spatial representation and hierarchical spatial reasoning ...

Abstract Unusual hydrothermal native As-sulfide ± Ag arsenide antimonide sulfosalt ore shoots and their co-genetic sulfide-fluorite-barite-quartz host veins, which are common in the region whole Central Europe, were investigated at three localities Schwarzwald, SW Germany, to understand physico-chemical processes governing change from a normal (= common) an exceptional shoot regime. Based on fl...

Porphyry deposits are the dominant sources of copper and major several base precious metals. They commonly formed via repeated emplacement hydrous magmas associated fluid exsolution. As a result, mineralized hydrothermal veins may undergo multiple deposition reopening processes that not fully accounted for by existing models. The Tongchang porphyry Cu deposit is rare example being related to si...