نتایج جستجو برای: ایزوتوپهای nd sr
تعداد نتایج: 58174 فیلتر نتایج به سال:
Abstract During the Mexican fold-and-thrust belt tectonics, inboard migration of long-term cordilleran magmatism typifies geological setting during Cretaceous–Paleogene period. The Concepción del Oro Igneous Complex (COIC) represents one most internal and isolated magmatic pulses that occurred this activity. In work, plutonic rocks from COIC were studied using petrography, U–Pb geochronology, w...
[1] Among volcanic hot spots globally, Hawaii has the highest magma flux, yet there is significant controversy surrounding the composition of the mantle sourcing Hawaiian lavas. In order to place constraints on the source lithologies of Hawaiian lavas, we explore relationships between major elements and radiogenic isotopes in tholeiitic, shield-building lavas. Olivine-fractionation corrected la...
introduction there are some theories about the paleotethys event during the paleozoic that have been proposed by geologists (metcalfe, 2006). some scientist offered some pieces of evidence about the northern margin of gondwana (zhu et al., 2010). the paleotethys ocean and hercynian orogenic report first in iran, have been offered from the morrow and misho mountain (eftekharnejad, 1981). misho m...
We report herein on new zircon U–Pb ages, the major and trace elements of whole-rock, Sr–Nd–Hf isotope composition for adakitic intrusives collected from West Ujimqin district in Southeast region Central Asian Orogenic Belt (CAOB). These data provide important constraints petrogenetic evolution geodynamic setting late Permian magmatism CAOB. The dating shows that ages Seerbeng pluton Nuhetingsh...
We present evidence for a thick ( 100 km) sequence of cogenetic rocks which make up the root of the Sierra Nevada batholith of California. The Sierran magmatism produced tonalitic and granodioritic magmas which reside in the Sierra Nevada upperto midcrust, as well as deep eclogite facies crust/upper mantle ma®c±ultrama®c cumulates. Samples of the ma®c±ultrama®c sequence are preserved as xenolit...
تودهی نفوذی قلای لان، توده ای وابسته به ژوراسیک پسین، متشکل از سنگ های حدواسط تا فلسیک است که در بخش شمالی پهنهی سنندج – سیرجان رخنمون دارد. توده ای متشکل از سنگ های قلیایی، پتاسیم بالا، فروئن و وابسته به گروه گرانیت هایa۱-type که ویژگی های دوگانه ای به نمایش می گذارد؛ از یک سو ویژگی های ایزوتوپی nd و sr نشان از دخالت خاستگاهی گوشته ای با ویژگی های اولیه دارد، از سوی دیگر وجود هسته های زیرکن...
New Rb-Sr, (146,147)Sm-(142,143)Nd and Lu-Hf isotopic analyses of Mg-suite lunar crustal rocks 67667, 76335, 77215 and 78238, including an internal isochron for norite 77215, were undertaken to better define the time and duration of lunar crust formation and the history of the source materials of the Mg-suite. Isochron ages determined in this study for 77215 are: Rb-Sr=4450±270 Ma, (147)Sm-(143...
Metalliferous sediments deposited on and near spreading ridges show contrasting geochemical signatures depending whether deposition occurred in a restricted basin filled with anoxic dense brines, or an open ocean characterized by oxidized well-circulated seawater. of the Atlantis II Deep, which are precipitated from ca. 60 °C display wide range mineralogical chemical facies. The most abundant f...
Optimum (La 0.2 Nd Sm Ca Sr )MnO 3 exhibits excellent high-temperature resistance to elemental segregation and chemical compatibility with 8YSZ while maintaining good electrical conductivity.
منطقه مورد مطالعه در زاغه، در 35 کیلومتری جنوب شرقی دیواندره، استان کردستان، و بخش کوچکی از نقشه زمین شناسی (1:100000) چهارگوش دیواندره می باشد. واحدهای اصلی لیتولوژی این منطقه از قدیم به جدید عبارتند از: کلریت شیست (پرمین)، کربنات های سازند روته (پرمین میانی- بالایی)، توده ی نفوذی مافیک (بعد از کرتاسه) و رسوبات کواترنری. افق رس دار داخل سنگ های کربناته سازند روته واقع شده است. فاز کانیایی اصلی...
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