نتایج جستجو برای: sodic-calcic and potassic alterations
تعداد نتایج: 16837401 فیلتر نتایج به سال:
exact petrography and mineral chemistry investigations of pristine and altered rocks of the post-eocene panj-kuh pluton show thatsubsequent to emplacement and crystallization, rocks were subjected to two secondary composition equivalents, sodic-calcic andpotassic alterations, respectively. fresh rocks have syenitic composition and contain plagioclase (labradorite), k-feldspar, magmaticdiopside,...
Reduction of fossil fuels sources, increasing of pollution gases emission, and global warming effects increase the demand of renewable fuels. One of the main candidates of alternative fuels is biodiesel. Biodiesel limits greenhouse gas effects due to the closed CO2 cycle. Biodiesel has more biodegradability, lower combustion emissions such as CO, SOx, HC, PM and lower toxicity than petro diesel...
The Upper Jurassic Mantos Blancos copper deposit (500 Mt at 1.0% Cu), located in the Coastal Range of northern Chile, displays two superimposed hydrothermal events. An older phyllic alteration probably related to felsic magmatic–hydrothermal brecciation at ∼155 Ma, and younger (141–142 Ma) potassic, propylitic, and sodic alterations, coeval with dioritic and granodioritic stocks and sills, and ...
Colorless sodic and sodic-calcic amphiboles occur in piemontite-quartz schists in the Asemi-gawa (garnet zone) and Besshi (albite-biotite zone) areas of high P-low T Sanbagawa metamorphic belt in central Shikoku, Japan. Colorless sodic amphiboles in the Asemi-gawa area are glaucophane while colorless sodic-calcic amphiboles from the Besshi area are barroisite and magnesiokatophorite. Colorless ...
clinopyroxene phenocrysts and microphenocrysts in potassic and sodic eosen alkaline volcanic rocks from the northern lahrud (nw iran) record various stages in the crystallization and evolution history of the alkaline melt as well as its origin. the rock series hosting the clinopyroxene phenocrysts is phonolitic tephrite and tephritic phonolite composition. theses rocks generally show porphyriti...
Brownfield areas are important targets of exploration; however, the extensive drilling present in these has not fully exploited their prospective potential. The appropriate use drill hole cores can play an role deep exploration. We a case study iron oxide-copper-gold (IOCG) Furnas Southeast deposit, located Carajás Mineral Province, Brazil. This deposit disseminated chalcopyrite, bornite and go...
The ~1.08 Ga anorogenic, A-type Pikes Peak batholith (Front Range, central Colorado) is dominated by coarsegrained, biotite±amphibole syenogranites and minor monzogranites, collectively referred to as Pikes Peak granite (PPG). The batholith is also host to numerous small, late-stage plutons that have been subdivided into two groups (e.g. Wobus, 1976. Studies in Colorado Field Geology, Colorado ...
بررسیهای ژئوشیمی و رادیوایزوتوپی برای تعیین خاستگاه آپاتیت در ذخایر آهن و آپاتیت منطقهی معدنی بافق
The iron-apatite deposits of the Bafq mining district contain elevated REE content and occur together with vast alterations in country-rock which were formed due to widespread hydrothermal processes in Early Cambrian. Apatite and rare earth element geochemistry as well as radioactive isotope studies of Sm-Nd show that apatite formation might be due to hydrothermal activities and remobilization ...
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