نتایج جستجو برای: monzogranite and leucogranite quartz
تعداد نتایج: 16829375 فیلتر نتایج به سال:
bibi maryam granitoid body with about 5 km2 has intruded into ophiolite mélange complex in sistan suture zone, in east of iran. thermal effects of this body on the host rocks show that this activity occurred after emplacement of ophiolite mélange. this intrusive body with general northwest – southeast trend is mainly tonalite-quartz diorite but there is a minor unit as dykes of granodiorite in ...
AIMS To reanalyse exposure-response data from a Scottish colliery to gain a more detailed knowledge of the relations between exposure to quartz and risks of silicosis in coal miners, and hence inform the debate on an appropriate occupational standard for respirable quartz. METHODS Detailed data on working times at different quartz concentrations were combined to produce exposure profiles for ...
The Miocene Qohrud granitoid intrusion consists of granite, granodiorite and tonalite and is located in the Urmia-Dokhtar magmatic belt. Intrusion of magmatic rocks into the various sedimentary rocks including shale, sandstone, limestone and marl, with Jurassic to Eocene age, has caused contact metamorphism of the surrounded rocks. Varity of hornfelses and skarns are formed in this regards. Hyd...
A further comparison of the Health and Safety Executive (HSE) standard quartz, A9950 (Sikron F600), and the National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1878, standard respirable alpha-quartz, has been carried out for the four principal diffraction peaks. In the earlier comparison by Jeyaratnam and Nagar (1993, Ann Occup Hyg; 37: 167-79), the standards...
The X-ray diffraction method and the phosphoric acid method are widely used to determine the fraction of free silica (mainly quartz and other silica polymorphs) in respirable dust sampled in working environments in Japan. In this study, we clarified the size effect of quartz dust for the X-ray diffraction method and the phosphoric acid method using size controlled quartz samples. The quartz sam...
The quartz-aluminosilicate veins in the Hamadan region consist of quartz with one, two or three polymorphs of aluminum silicate )andalusite, kyanite and sillimanite(. In some veins other accessory minerals (i.e. garnet, chlorite, muscovite, staurolite, biotite and plagioclase) are present. The petrogenesis of these veins and their country rocks have been previously described; this paper studies...
Onzon-Kanbani area is a western flank of Mogok Metamorphic Belt where gold mineralization is hosted as auriferous quartz-vein with epithermal low-sulphidation characters. Mineralization is closely associated with NE-SW trending fracture or shear zone probably related to the dextral movement of the Sagaing Fault system. Mineralization related hydrothermal alteration is developed as narrow zones ...
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...
Abstract Rubidium (Rb) deposits mostly occur in the South China and Central Asia orogenic belts are often closely associated with highly differentiated granites. This study aimed to investigate a newly discovered giant Rb deposit at Gariatong Lhasa terrane Tibet. Detailed field studies logging data revealed that mineralization mainly occurrs monzogranite is related greisenization. LA‐ICP‐MS U‐P...
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