نتایج جستجو برای: alkaline volcanic
تعداد نتایج: 57247 فیلتر نتایج به سال:
Nosrat-Abad ophiolitic extrusive sequence, located in the Sistan Suture Zone, in south eastern Iran. The extrusive sequence, contains pillow lava, sheet flow and related volcanic-clastic breccias which have undergone low-grade metamorphism. This association shows calc alkaline to tholeiitic affinities. Interpretation of the geochemical data and behavior of the elements in different diagrams rev...
There are scattered exposures of young volcanic rocks in Hamun Lake Area in south western and north western of Zabol in east of Iran. The microscopic evidences and geochemical analysis show that these rocks are olivine basalt and basalt to trachy basalt. The main textures of these rocks are porphyry, microlitic porphyry and vesicular. The main phenocrysts of these rocks are olivine, clinopyroxe...
کاربرد شواهد کانی شناسی و بافتی در تشخیص دگرنهادی آلکالن در استوک گرانیتوئیدی دودهک (شمال شرق محلات)
Dodehak granitoid stock with tonalite to granodiorite compos ition is exposed south of Dodehak vi llage, north of Ab-e-Gann (Mahalat) in Urumieh-Dorhtar volcanic belt of Iran. Based on petrography and point analysis (EPMA). plagioclase crystals show nonnal zoning with graph ic tex.ture is present. Samples from SE of the intrus ion are different and myrmekite texture is present in the rocks...
Abstract Variable single and/or swarms of post-granitic dikes are widespread at Gabal Serbal, Southwestern Sinai, Egypt. The present article aims to identify and discriminate these multiphase through detailed geological, petrographical, geochemical examinations. These classified into two subphases: (1) acidic (porphyritic dacite, microgranite, granophyre, alkaline granophyre dikes); (2) basic (...
Abstract A comprehensive mineralogical, geochemical and isotopic review of six ultramafic-alkaline-carbonatite magmatic intrusions the Shillong Plateau (Sung Valley, Jasra, Swangkre-Rongjeng, Mawpyut) Mikir Hills (Samchampi-Samteran Barpung) is presented here, using published data. These emplaced ca. 115–102 Ma ago, thus are significantly younger than tholeiitic flood basalts erupted in Rajmaha...
A calibrated radiocarbon database of late Quaternary volcanic eruptions R. U. Bryson, R. A. Bryson, and A. Ruter National Park Service, Mojave National Preserve, 2701 Barstow Road, Barstow, CA 92311, USA Center for Climatic Research, University of Wisconsin-Madison, 1225 W. Dayton St., Madison, WI 53706, USA Received: 24 May 2006 – Accepted: 17 July 2006 – Published: 25 July 2006 Correspondence...
The study area is located about 45 km of southwest Neyshabour and east of Arghash village. Both intrusive and volcanic rocks are exposed in the study area and they are intensively altered due to hydrothermal fluid. The alteration zoning in the study area consists of potassic, sericitic, carbonatization, silicification and propylitic. More than 10 intrusive rocks with composition in the range of...
The study area is located in Central Iranian volcano-plutonic copper belt (Dehaj-Sarduiyeh belt) about 42 Km northeast of Shahrbabak in Kerman Province. Based on petrographic studies, extrusive rocks have the composition from trachyandesite, andesite basaltic and andesite to dacite with Eocene age. Mineralogically, the rocks contain plagioclase, amphibole, biotite and quartz. Chlorite, calcite,...
The study subvolcanic intrusion, comprising syenodiorite, monzonite and quartz-monzonite, is cropped out in Talkh-rud valley located in the northeast of Damavand volcano flank. This sub-volcanic intrusion possesses porphyritic texture and consists of plagioclase, alkali feldspars, phelogopite, amphibole, clinopyroxene, apatite and titanomagnetite. Evidences of disequilibrium such as zoning and ...
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