Sm-Nd isotopic data for metabasic rocks in central Brazil: constraints for the timing of mafic magmatism and regional magmatism
نویسندگان
چکیده
منابع مشابه
Sm-Nd Isotopic Data and Earth's Evolution.
Samuel A. Bowring and Todd Housh (1) report Sm/Nd isotopic data giving a wide range of initial ENd values, from +3.5 to -4 at 4.0 billion years ago (Ga) and from +4 to -7 at 3.6 Ga. Their samples were from the Acasta gneisses of northern Canada, which represent the oldest known outcrops of continental crust (2). Their modeling of the Sm-Nd isotopic data is taken to suggest that the Acasta grani...
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Numerous post-ophiolite intrusions exposed into the late Cretaceous–Paleocene Sabzevar ophiolite belt, northeast Iran. The intrusions consist of calc-alkaline intermediate to felsic rocks with metaluminous to peraluminous in nature and adakitic affinities. Based on U-Th-Pb dating on separated zircons by SHRIMP Ⅱ, the emplacement age of these rocks into the ophiolite zone is constrained to ~45 M...
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15 صفحه اولGeochemical and isotopic (Nd and Sr) constraints on elucidating the origin of intrusions from northwest Saveh, Central Iran
Three intrusive granitoid bodies from northwest Saveh, central Iran, are embedded in volcanic sedimentary rocks of the Eocene,forming isolated small outcrops: Khalkhab quartz monzodioritic units (SiO2: ~52-57 wt %) to the northwest, Neshveh granodioriticunits (SiO2: ~62-71 wt %) to the northeast, and Selijerd granodioritic units (SiO2: ~63-69 wt %) to the southeast. The Khalkhab unit iscomposed...
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The origin and geodynamic setting of the Maden Complex, which is situated in the Bitlis–Zagros Suture Zone in the Southeast Anatolian Orogenic Belt, is still controversial due to lack of systematic geological and geochemical data. Here we present new whole rock major–trace–rare earth element data from the Middle Eocene volcanic rocks exposed in Maden Complex and discuss their origin in the ligh...
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ژورنال
عنوان ژورنال: Anais da Academia Brasileira de Ciências
سال: 2001
ISSN: 0001-3765
DOI: 10.1590/s0001-37652001000300038