نتایج جستجو برای: alkaline volcanic
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The Pliocene calc-alkaline volcanic rocks are exposed in two areas in southeast and northwest of Isfahan and consist of andesites and dacites. Based on geochemical data and multi- elements pattern, these rocks are medium to high calc-alkaline suite and they show LILE and LREE enriched normalized multi-element patterns, and negative Nb and Ti. Condrite-normalized REE patterns display a steep dec...
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...
the neogene intrusion masses in the noudeh-enghelab area located to the north of sabzevar ophiolite have cut the late cretaceous ophiolitic rocks, sedimentary- volcanic and eocene volcanic rocks and have been covered by pliocene and quaternary deposits. the margin is of lava with basalt, phyric andesite-basalt and andesite and the central parts (dome shaped) composed of phyric andesite-trachyan...
The northeast region of Birjand is located in Lut structural and geological province. In this area we can distinguish two separate volcanic rock groups: intermediate to acidic volcanic rocks, including dacite, andesite, rhyolite and trachyandesite; and basic rocks, including basaltic andesite, mugearite and basalt. In this region, intermediate to acidic rocks, which belong to the Eocene-Miocene...
zeolites due to their structures can be used as molecular sieves for purification of materials and solutions. zeolites with phi and sod structure are so common and applicable for this purpose. hydroxy sodalite and phillipsite are the more abundant members of zeolites which display good selectivity for very small molecules and some ions such as sr, pb, zn, cu and rb. there is not any pure natura...
The Nikuyeh district is located south of the Tarom-Hashtjin metallogenic province in Western Alborz. Oligo-Miocene subvolcanic intrusion and Mid-Eocene volcanic rocks with composition of dacite to andesite are main igneous settings associated with Nikuyeh polymetallic epithermal ore mineralization. Igneous phase in the Nikuyeh district are porphyritic granodiorite, monzodiorite, quartz monsonit...
the lut block in eastern iran is a micro-continental block within the convergent orogen between the arabian, eurasian and indian plates. large areas of the north-central, eastern, and western lut block are covered by volcanic rocks of paleogene, neogene and quaternary age. peak volcanic activity took place in the north-central part of the lut block during the eocene, and then dramatically decr...
Phillipsite has formecl from volcanic glass in saline, alkaline lakes both saturated and undersaturated with respect to gaylussite and trona. It has also formed from volcanic glass in saiine, alkaline soils of Olduvai Gorge, Tanganyika. Phillipsite occurs both as lath,shaped and as equant crystals, which are commonly zoned lvith refractive indices ranging between 1.438 and 1.490. Molecular SiOz...
Hamyerd iron deposit is located about 74 km north east of Semnan, in the Jam area. This area is situated in the northern part of Central Iran structural zone. The outcrops are Middle-Eocene volcanic and pyroclastic rocks with andesite to andesite-basalt and tuff composition, which are intruded by some intrusive bodies of monzonite to monzodiorite composition in this area. Iron mineralization is...
Hydroxy davyne is a hydrated aluminosilicates with the same structure as cancrinite mineral group. Scientist categorized hydroxy davyne as zeolite because of its low temperature formation conditions and hydrated structure. Existence of [Ca.Cl] + group instead of [Na.H2O] + group is the significant property of this mineral. Alteration of volcanic ash in presence of alkaline hydrothermal solution...
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