نتایج جستجو برای: felsic composition
تعداد نتایج: 260277 فیلتر نتایج به سال:
The mineralogy and geochemistry of Paleocene shales and interbedded siltstones in the southwestern of Ahar town (NW Iran) were studied by optical microscopy, XRD, SEM, XRF, and ICP-MS techniques. The mineralogical composition, mainly characterized by calcite, quartz, feldspar, dolomite, muscovite, magnesiohornblende, chlorite, illite, montmorionite, palygorskite, and koninckite, suggests relati...
Gneisses of the northern part of the Zayandehrood Dam Lake, structurally, are located in the Sanandaj-Sirjan zone. The gneises with phengitic marble and metabasic bodies comprise a part of high-pressure units in the North Shahrekord metamorphic complex. Minerlogically, the rocks consist of quartz, garnet, phengite, k-feldspar, albite, tourmaline and rutile with zircon grains. Field (alternation...
شیمی کانی و بررسی نقش آلومینیوم کل بیوتیت برای تشخیص نوع کانیزایی در تودههای نفوذی محور کرج-طالقان
The intrusive bodies of Karaj-Taleghan axis in Central Alborz constitute, intruded the pyroclastic rocks of Karaj Formation in the form of sill, lopolith, stock and plug with distict distribution. Based on microscopic studies, these bodies have similar lithological composition and include olivine gabbro, olivine monzodiorite, olivine monzonite, pyroxene monzonite with felsic dikes of syenite. T...
Jarou deposit, with age of Middle Eocene –Oligocene, is located in 60 km to the southwest of Karaj and lies within magmatic rocks with felsic to basic composition. Host rock geochemical results have implied a calc-alkaline nature, magmatism related to an extensional back arc regime and lack of economic potential for igneous rocks. Petrographic and geochemical evidences of Cu minerals have shown...
The nature of the crust beneath central Iberia was estimated by a wide-angle seismic reflection/refraction transect, ALCUDIA-WA, which sampled southern half Variscan Central Iberian Zone, covered in north Cenozoic Tajo Basin. shot gathers recorded vertical component sensors revealed well defined P- and S-wave phases. These arrivals were modeled an iterative forward approach providing 2D crustal...
The Euganean Hills (NE Italy) magmatic district represents the final volcanic activity of Veneto Volcanic Province. Alkaline to subalkaline suite dominated by intermediate felsic rocks characterises latest Hills. Magmatic (intrusive and volcanic) enclaves are common in trachytes. We used ability clinopyroxene record variations P, T, fO2 reconstruct geological history trachytic host. Despite sim...
Abstract Petrography has long been used as a tool to decipher the sedimentary provenance of sand and sandstone based on relative proportions detrital grain types. However, there is not yet predictive framework that constrains relationship between composition factors influence it, including bedrock lithology, elevation, slope, basin area, precipitation, temperature. We globally extensive modal p...
Many granitic intrusions display evidence of magma mixing processes. The interaction melts contrasting composition may play a significant role during their generation and evolution. Strzegom-Sobotka massif (SSM), located in the Sudetes (SW Poland) north-eastern part Bohemian Massif Central European Variscides, exhibits mingling on macro- micro-scales. The massif is composite intrusion, with fou...
Abstract. Back-arc extension superimposed on mountain belts leads to distributed normal faults and shear zones interacting with magma emplacement within the crust. The composition of granitic magmas emplaced at this stage often involves a large component crustal melting. Miocene Aegean granitoids were in metamorphic core complexes (MCCs) below crustal-scale low-angle ductile zones. Intrusion pr...
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