نتایج جستجو برای: alkaline volcanic
تعداد نتایج: 57247 فیلتر نتایج به سال:
The compositional record of the AND-2A drillcore is examined using petrological, sedimentological, volcanological and geochemical analysis of clasts, sediments and pore waters. Preliminary investigations of basement clasts (granitoids and metasediments) indicate both local and distal sources corresponding to variable ice-volume and ice-flow directions. Low abundance of sedimentary clasts (e.g.,...
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...
Western Turkey has been dominated by N–S extension since the Early Miocene. The timing and cause of this N–S extension and related basin formation have been the subject of much debate, but new data from the Bigadiç borate basin provide insights that may solve this controversy. The basin is located in the Bornova Flysch Zone, which is thought to have formed as a major NEtrending transform zone d...
Eocene volcanic rocks in south of Asad Abad (north-east of Koohpayeh, Isfahan Province) experienced very low-grade metamorphism (hydrothermal metamorphism), resulting in prehnite, malachite, azurite, zeolite, quartz and calcite crystallization in cavities and fractures. Chlorite (brunsvigite) and amphibole (ferro-actinolite) appear on secondary phases. Augite and labradorite are two main minera...
introduction in the east and northeast of sanandaj in the qorveh-bijar-takab axis, there are series of basaltic composition volcanoes with quaternary age. the study area is part of the sanandaj-sirjan zone and is located between 47°52' and 47°57' e longitudes and 35°26 and '35°30' n latitudes. due to the location of the volcanic cone on pliocene clastic sediments and quaternary travertine, the ...
The study area is located at 130 km northwest of Nehbandan in South of Khorasan and is a part of the rectangular Chahvak (Dehsalm). Dacite, rhiodacite, andesite, rhyolite, tuff and lithic tuff with Eocene age are recognized in the study area. According to mineralogy, mentioned rocks include plagioclase, quartz, pyroxene, amphibole, biotite and alkaline feldspar. Plagioclase consists of zonal st...
Post-Eocene volcanic rocks of Alborz tectonic zone located in the NE of Qazvin, composed of rhyolite, trchydacite, trachyandesite, andesite, trachybasalt and basalt with porphyritic textures, pyroclastic rocks and volcanic red breccia which are settled alternatively on Eocene pyroclastics and tuffs. The volcanic rocks are enriched in LIL and depleted in HFS elements which may indicate a calc-al...
late miocene–pliocene calc-alkaline volcanic rocks are exposed southeast of isfahan in the urumieh-dokhtar magmatic belt. volcanic rocks consist of lava flows and domes, chiefly basaltic andesites, andesites and dacites. minerals in the volcanic rocks exhibit degrees of disequilibrium features. plagioclase as dominant mineral in these rocks generally displays reverse and oscillatory zoning; sie...
The study area is located in the east of Ahar town in Eastern Azerbaijan Province and is part of the Ahar-Arasbaran Cenozoic magmatic belt of NW Iran. The geological units of the Eocene age are volcanic rocks with andesite, latite - andesite and basaltic andesite composition. Khankandi and Useflu Oligocene intrusive bodies intruded in the volcanic rocks and caused widespread alteration and copp...
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