نتایج جستجو برای: alkaline volcanic

تعداد نتایج: 57247  

1995
G. M. Yogodzinski R. W. Kay O. N. Volynets A. V. Koloskov S. M. Kay

The role of the subducting lithospheric slab in the genesis of mantle-derived (primitive) magmas is investigated through a study of volcanic rocks formed in the tectonically strike-slip–dominated western Aleutian arc. Two types of chemically and petrologically distinctive primitive andesites have been found among the Miocene– late Pleistocene–age volcanic rocks in the western Aleutians. These a...

Ahmadipour, hamid, Moeinzadeh, hesam aldin, Moradian, Abbas, Salehinejad, Hamideh,

In The northern part of Kerman Volcanic Belt, southwest of Rafsanjan (Deh-Zahir area), a series of diabasic intrusives have intruded into the Eocene andesitic lava flows and pyroclastic rocks. These plutons occur as irregular shaped bodies (up to 8 m in diameter) and dikes (up to 4 m in thicknesses). They show ophitic, sub-ophitic, and porphyritic textures and their major minerals include plagi...

جهانگیری, احمد, خضرلو, علی اکبر, عامل, نصیر, مؤید, محسن, گری گوایر, میشل,

Alkaline volcanic rocks of the northwest of Marand with Plio-Quaternary age are located in the northern part of Urumieh-Dokhtar Magmatic Arc. These rocks have a distinct enrichment in LILE and LREE and depletion in HFSE (such as Ta and Nb) and high Ba/Ta and Ba/Nb ratios, which are among the characteristics of subduction zones. The majority of hornblenditic autholiths and hornblenditic xenolith...

پورمعافی, سیدمحمد , یوسف‌زاده, محمدحسین, امامی, محمد هاشم , سبزه‏ئی, مسیب, وثوقی عابدینی, منصور ,

The Tertiary volcanic rocks in the north and west of Birjand are dacite; andesite, basaltic andesite, trachyandesite and rhyolite.They belong to calc- alkaline from magmatic series. Mineralogcal, petrographcal and geochemical evidence show that they have formed in active continental margins. Most andesites and dacites are appeared as volcanic domes or subvolcanic dykes that injected older units...

ژورنال: کواترنری ایران 2019
Khajei, Ali Mohammad , Mahmoudi , Shahriar ,

Sciences, Kharazmi University Introduction Petrogenesis of continental magmatic arc is more complicated than oceanic arcs. Because some various parameters affect the composition of magmatism in the congenital margin, such as continental crust contamination, mixing with crustal magmas and the deformation phenomena from primary mantle magma (Martin et al., 2005; Eyuboglu et al., 2018; Pawley and...

1996
Ian S.E. Carmichael

The Aurora volcanic field, located along the northeastern margin of Mono Lake in the Western Great Basin, has erupted a diverse suite of high-K and shoshonitic lava types, with 48 to 76 wt% SiO2, over the last 3.6 million years. There is no correlation between the age and composition of the lavas. Three-quarters of the volcanic field consists of evolved (,4 wt% MgO) basaltic andesite and andesi...

Journal: :International journal on data science and technology 2021

The scientific knowledge of geological sites is a model to recognize the scores stablish geoconservation and education/touristic proposes in geoparks territories. alkaline massif Pocos de Caldas structure igneous origin (with volcanic hypabissal deposits), formed, roughly, by breccias tufts, effusive rocks plutonic rocks. purpose this article international relevance Alkaline Massif (Minas Gerai...

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