نتایج جستجو برای: alkaline volcanic

تعداد نتایج: 57247  

Journal: :زمین شناسی اقتصادی 0
سمیه فلاحتی موسی نقره ئیان مرتضی شریفی قدرت ترابی همایون صفایی محمد علی مکی زاده

introduction the study area is located in the shurab area that is about 50 km southeast of qom. volcanic rocks of the shurab area have basaltic composition that is associated with salt and marl units. igneous rocks of the shurab area have not been comprehensively studied thus far. clinopyroxene composition of volcanic rocks, and especially the phenocrysts show magma chemistry and can help to id...

Journal: :Atlantic Geology 2021

Volcanic rocks of the Ediacaran Musgravetown Group on Bonavista Peninsula, Avalon terrane, Newfoundland, include basal ca. 600 Ma calc-alkaline basalt succeeded by continental tholeiite and alkaline rhyolite 592 Plate Cove volcanic belt (Bull Arm Formation), indicating a change from subduction-related to extensionrelated tectonic regimes during that interval. Alkalic basalts northeastern (Dam P...

Journal: :journal of sciences islamic republic of iran 0

the oligocene-miocene granitic rocks of deh siahan, part of central iranian volcanic belt, are intruded into eocene volcano-sedimentary complex where their contact is marked by albite-epidote hornblende hornfels facies and granitic apophyses. the granitic rocks show enhanced lil element abundances and low hfs/lil ratios. geochemical data, various trace element discriminant diagrams, enhanced y/...

Journal: :زمین شناسی اقتصادی 0
فرشته بیات قدرت ترابی

metagabbro, metadiabase and metabasalt of the chah palang and me'raji mountains associated with lower paleozoic metamorphites are situated in the south of arousan. metabasites of these areas are relatively similar in terms of mineralogy and geochemical characteristics. rock-forming minerals of the me'raji metabasites are feldspar, amphibole, biotite, sphene, epidote, chlorite ± calcite. metagab...

Journal: :Geological Society, London, Memoirs 2021

Abstract Erebus volcano, Antarctica, is the southernmost active volcano on globe. Despite its remoteness and harsh conditions, provides an unprecedented unique opportunity to study petrogenesis evolution, as well passive explosive degassing, of alkaline magmatic system with a persistently open magma-filled conduit. In this chapter, we review nearly five decades scientific research related inclu...

Journal: :journal of tethys 0

sahand volcanic-sub-volcanic dome, along with several other magmatic domes in northwest iran and the southern part of tabriz fault show adakitic geochemical characteristics. sahand dome has mainly dacitic composition. the sio2 content and mg number of sahand dome range from 64 to 73 wt% and 27 to 57 respectively. sahand dome can be classified as high silica adakitic (hsa) type. the rocks studie...

Journal: :Frontiers in Earth Science 2023

The Tengchong Cenozoic volcanic field lies in SE margin of the Tibetan Plateau. basalts exhibit evident spatial-temporal variations, but consensus on their meaning has not been reached yet. In this study, we collected from western, central and eastern areas measured whole-rock olivine major trace elements basalts. remarkable chemical isotopic diversity, showing a strong correlation with eruptio...

2003
Ryoichi Mizuno Yoshinori Dobashi Bing-Yu Chen Tomoyuki Nishita

In this paper, we present a physics motivated modeling method for volcanic clouds as a two fluids model. Some previous methods model smoke or clouds as one fluid, but the volcanic clouds can not be treated as one fluid. The volcanic clouds consist of the pyroclasts, the volcanic gas and the entrained air. Since the pyroclasts and the volcanic gas can be treated as one fluid, called magma, the v...

Ahmadi Khalaji, Ahmad, Kamran, saeed, Rezaei-Kahkhaei , mahdi, Tahmasbi, Zahra,

The Nokeh intrusion exposed in the northern Semnan area. The intrusion is composed of monzonite-quartz monzonite and granite-granodiorite and was intruded in the Eocene carbonaceous tuffs, where the country rocks converted to magnetite-skarn. Plagioclase, orthoclase, quartz, biotite, amphibole and clinopyroxene are the constituent minerals of Nokeh intrusion. The study rocks represent granular,...

رضائی کهخائی, مهدی, قاسمی, حبیب اله, قصابی فیض, آزاده,

Eocene volcanic and volcano- sedimentary rocks cover a large area in the Gardaneh Ahovan northeast of Semnan. These rocks comprise mainly of basalt, andesite, trachyandesite, rhyolite and dacite with hyalo porphyry, porphyry and glomeroporphyry textures. The basaltic rocks are composed of plagioclase and clinopyroxene phenocrysts. Sericite, kaolinite, calcite and chlorite also form the secondar...

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