نتایج جستجو برای: ایزوتوپهای nd sr
تعداد نتایج: 58174 فیلتر نتایج به سال:
salafchegan-khorhe volcanic rocks are exposed within urumieh-dokhtar magmatic belt. different kinds of volcanic and subvolcanic rocks of calc-alkaline to alkaline character have been reported throughout this magmatic belt. since, isotopic investigations are very useful for detection of magma petrogenesis and because no isotopic studies have been done in this area, so a geochemical and isotopic ...
Fluorite is a widespread mineral in porphyry and hydrothermal vein Mo-polymetallic deposits. Here, fluorite utilised as probe to trace the fluid source reveal evolution process Chalukou giant Mo (Pb–Zn) deposit, Northeast China, which characterised early later vein-style Zn–Pb mineralisation. A detailed rare earth element (REE) Sr–Nd isotope study of combined with Sr isotopes sphalerite conduct...
واحدهای مورد مطالعه در شمال باختر سبزوار و در دامنه جنوبی نوار افیولیتی شمال سبزوار واقع شده است. تعداد زیادی گنبدهای آتشفشانی با ترکیب ریولیتی (گنبد ساروق، زردکوهی، کوه سفید مهر و نهر) واقع در بخش جنوبی نوار افیولیتی داورزن - سبزوار به داخل سنگهای این مجموعه افیولیتی نفوذ کردهاند. ویژگیهای ژئوشیمیایی نمونههای مورد مطالعه، از جمله غنیشدگی از عناصر LREE و LILE نسبت به HREE و HFSE، بی...
Tourmalinization characterizes the most pervasive alteration type in the Nezam Abad ore deposit, west-central Iran. It delineates high-temperature centers of mineralization and together with quartz and cassiterite form inner parts of the alteration halo. The composition of tourmalines plots mostly along and between the proton and alkali-deficient end members. Tourmaline in quartzdioritic host i...
Understanding the subduction and recycling of continental crust is crucial for reconstructing long-term evolutionary history Earth's mantle crust. The Himalaya-Tibet orogen arguably world's best natural laboratory investigating these processes. Cenozoic post-collisional ultrapotassic volcanic rocks are common in Lhasa block southern Tibet they can provide important clues to crust-mantle interac...
Linear, north–south trending Peddavura greenstone belt occurs in easternmost part of the Dharwar Craton. It consists of pillowed basalts, basaltic andesites, andesites (BBA) and rhyolites interlayered with ferruginous chert that were formed under submarine condition. Rhyolites were divided into typeI and II based on their REE abundances and HREE fractionation. Rb–Sr and Sm–Nd isotope studies we...
Introduction: Many questions regarding the petrogenesis of mare basalts remain unresolved. Trace element and isotope geochemists tend to view the range of mare basalt compositional groups as independent primary magmas and develop mantle melting models to explain the compositional diversity [e.g. 1, 2, 3]. On the other hand, petrologists view the mare basalt suites as non-primary and suggest tha...
Article history: Received 11 October 2016 Accepted 5 January 2017 Available online 14 January 2017 The Siletz terrane, a predominantly mafic accreted oceanic terrane, is located in the Cascadia forearc region of Oregon, Washington and Vancouver Island. The terrane represents a late Palaeocene–Eocene large igneous province that consists of pillow lavas, massive flows and intrusive sheets. Previo...
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