نتایج جستجو برای: mineral rocks
تعداد نتایج: 86424 فیلتر نتایج به سال:
Eocene volcanic rocks in NE of Ordib, have a very good exposures near and along the Turkmeni-Ordib fault. These rocks, that are situated in the inner part of the Central Iran and margin of the Yazd block, comprise trachyte, trachy-andesite and basaltic trachy-andesite. Trachy-andesite is the pervasive rock unit. Rock forming minerals of these rocks are chloritized olivine, plagioclase, pyroxene...
Indurated surficial veneers are a characteristic phenomenon on exposures of unjointed granite in the southeastern states. They are caused by deposition of iron oxides in the interstices between the partially disaggregated mineral grains of the "sap" rock at the surface of the exposure. Breaching of veneers produces such peculiar erosional forms as weather pits, cavernous boulders, and pedestal ...
Northeast of Meshkinshahr, Eocene igneous rocks are exposed and are composed mainly of andesite, basalt, andesitic basalt, tephrite and is sometimes analcimite. The chemical composition of the rocks are in the range of alkaline rocks with high potassium and shoshsonitic affinity. Two main hypotheses are that they are either primary analcite or replacement pseudomorphous of leucite. Analcime cr...
chloritoid is crystallised with chlorite, white mica and garnet in chlorite zone metapelites ofthe regional metamorphic rocks of the sanandaj-sirjan metamorphic belt in southern iran. chemistry ofcoexisting minerals is studied using microprobe analysis. application of the chlorite-chloritoidgeothermometry gives temperatures of 515°c and 557°c. the chlorite-garnet fe-mg exchangegeothermometer in...
Introduction: We have shown earlier that the high SO 3 / Cl ratios found in secondary mineral assemblages in shergottite GRIM glasses (Gas-Rich Impact-Melt) likely resulted from interactions of regolith materials with sulfate-rich (and Cl-poor) solutions [1,2]. The low SO 3 /Cl ratios determined in secondary salts in nakhlite fracture-fillings presumably formed by rock interactions with chlorid...
The intrusive bodies of Central Alborz, with display lithological composition, include olivine gabbro, olivine monzodiorite, olivine monzonite and pyroxene monzonite. They are accompanied by pyroclastic rocks of the Karaj Formation, and they occur as sill, lopolith, stock and plug. The essential minerals of these rocks are plagioclase, alkali feldspar, pyroxene, olivine and biotite. Mineral che...
The Southern Caspian Sea ophiolite complex (SCO) is one of the Late Cretaceous discontinuous oceanic lithosphere remnants in northern Iran. These complex is almost a complete sequence from bottom to top, ultramafic cumulates, layered gabbros, isotropic gabbros, dike complex and basaltic lavas which is covered by Late Cretaceous (Companion- maaestirchtian) pelagic limestone. Crustal ultramafic c...
Bovaki and Aghbolagh tungsten (copper-tin-zinc) ore occurrences are located 12 and 14 km northwest of Azna respectively. The region is located in Sanandaj-Sirjan structural zone of Iran, at the complex deformation sub-zone. There are alternative comsisty Upper Triassic carbonate, quartzite and meta-volcanic rocks (such as meta-tuff). In this area, tungsten-copper mineralization occurs as strati...
Oxidation of manganese (II) to manganese (III,IV) demands oxidants with very high redox potentials; consequently, manganese oxides are both excellent proxies for molecular oxygen and highly favorable electron acceptors when oxygen is absent. The first of these features results in manganese-enriched sedimentary rocks (manganese deposits, commonly Mn ore deposits), which generally correspond to t...
Knowledge-and data-driven approaches are two major methods used to integrate various evidential maps for mineral prospectivity mapping (MPM). Geological maps, geochemical samples and data from known gold deposits were collected in the western Junggar area, Xinjiang Province. The geological and a spatial database for geological and mineral occurrences were constructed for the studied region. A w...
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