نتایج جستجو برای: alkaline rocks

تعداد نتایج: 64205  

مؤید, محسن ,

The rhyolitic flows and sills in the extremity of Ghal'eh-chay river (East of Ajabshir, East Azerbaidjan) are exposed in the Lalun sandstone deposits. Compositionally, these rocks are rhyolite and are composed of euhedral quartz phenocrystals and subhedral perthitic orthoclases in a glassy to fine grained matrix containing quartz, k-feldspar and minor sodic plagioclases. There are not any ferro...

الیاسی, زهرا, امامی, سید نعیم, نصر اصفهانی, علی خان, وهابی مقدم, بابک,

Subplutonic rocks of North Shahrekord at south-west of Iran as a part of Sanandaj - Sirjan tectonical zone have exposed as basic dykes. These rocks are dolerites with specific textures such as intergranular, intersertal, ophitic and poikilitic. The main constituteud minerals of the dolerites are plagioclase and clinopyroxene. The secondary minerals include sericite, calcite, chlorite, epidote, ...

2006
JOHN D. LANDOLL

The Mont Shefford alkaline complex of southern Quebec contains mafic rocks and both silica-oversatwated and -undersaturated syenites. Chemical and isotopic studies examine the relationship of the various lithologies. Isotopic, major, and trace-element compositions are consistent with derivation of all Iithologies from a common mafic paren! some of which evolved to a syenitic itage by fractional...

Journal: :زمین شناسی اقتصادی 0
ربابه جعفری موسی نقره ئیان محمد علی مکی زاده جواد قانعی اردکانی

nezam-abad area is located in southwest of shazand (arak) which is a part of sanandaj-sirjan zone. major intrusive rocks of nezam-abad are quartz diorite and minor amount of granodiorite. leucogranitic, pegmatite dykes and quartz-tourmaline veins were intruded the quartz diorite. quartz diorites are mainly composed of plagioclase, hornblende, biotite, quartz and pyroxene as major minerals. majo...

داودیان دهکردی, علیرضا, سخایی, زینب , شبانیان , ناهید , پایداری, محمد ,

Gabbroic rocks of Sarkobeh region are exposed as several intrusive bodies with a post-cretaceous age in north of Khomein city, Northern Sanandaj-Sirjan Zone. These igneous rocks are intruded in shale and limestone units which belong to cretaceous age. Main minerals forming the rocks are clinopyroxene, plagioclase and opaque. Microprobe analyses on the clinopyroxenes of the gabbros show a diopsi...

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...

2006
J. R. Michalski S. W. Ruff P. R. Christensen E. Cloutis

Introduction and background: Zeolite minerals are hydrated framework aluminosilicates common to altered volcanic and volcanoclastic rocks, and the soils derived from them [1]. The mineralogy, chemistry, textural context, and abundance of zeolites provides insight into chemical weathering, hydrothermal, and metamorphic processes on Earth, in a variety of climates and tectonic settings. Zeolites ...

Journal: :Science 2014
S M McLennan R B Anderson J F Bell J C Bridges F Calef J L Campbell B C Clark S Clegg P Conrad A Cousin D J Des Marais G Dromart M D Dyar L A Edgar B L Ehlmann C Fabre O Forni O Gasnault R Gellert S Gordon J A Grant J P Grotzinger S Gupta K E Herkenhoff J A Hurowitz P L King S Le Mouélic L A Leshin R Léveillé K W Lewis N Mangold S Maurice D W Ming R V Morris M Nachon H E Newsom A M Ollila G M Perrett M S Rice M E Schmidt S P Schwenzer K Stack E M Stolper D Y Sumner A H Treiman S VanBommel D T Vaniman A Vasavada R C Wiens R A Yingst

Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicate...

Journal: :journal of mining and environment 0
a. entezari harsini department of geology, ferdowsi university of mashhad, mashhad, iran s. a. mazaheri department of geology, ferdowsi university of mashhad, mashhad, iran s. saadat department of geology, mashhad branch, islamic azad university, mashhad, iran j. f. santos department of geosciences, geobiotec research unit, university of aveiro, aveiro, portugal

this paper presents the new geochemical isotopes sr and nd, and the mineralization data for the south neyshabour volcanic rocks located in ne iran. based on the chemical classifications, the studied rocks are basaltic trachy andesite, trachy andesite, trachyte, and trachy dacite in composition. all the analyzed volcanic rocks display enrichment in light rare earth elements (lree) relative to th...

1998
W. Frisch A. M. Abdel-Rahman

The Wadi Dib magmatic complex is the oldest known alkaline ring complex in the Egyptian part of the Pan-African orogenic belt. Rb-Sr isotope data for seven samples suggest a Vendian age of 578=k16 Ma, and a 87Sr/S6Sr initial ratio of 0.7048±0.0010. The igneous complex has a diameter of 2 km and was emplaced within granodioritic Pan-African host rocks at the intersection of two faults. It shows ...

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