Isotopic and elemental abundance signatures in the mass range Sr through Hf have been determined in a silicon carbide-rich sample of the Murchison carbonaceous chondrite, using inductively-coupled plasma mass spectrometry (ICP-MS). Despite the problem of isobaric interferences useful results were obtained for a number of isotopes, several for the first time. While disagreements between astrophy...

Mineral chemistry, major and trace elements and Sr-Nd isotopes are presented for basalts and trachybasalts from the Quaternary alkaline Tepi shield from southwest Ethiopia. The lavas are variably porphyritic with phenocrysts of olivine (Fo67–87), clinopyroxene (Wo45–47En38–40Fs13–16), plagioclase (An57–68) and Ti-magnetite set in a microcrystalline matrix. Although there are two high-MgO lavas ...

[1] Analyses of radiogenic neodymium (Nd), strontium (Sr), and lead (Pb) isotope compositions of clay‐ sized detrital sediments allow detailed tracing of source areas of sediment supply and present and past transport of particles by water masses in the eastern Indian Ocean. Isotope signatures in surface sediments range from −21.5 ("Nd), 0.8299 (Sr/Sr), and 19.89 (Pb/Pb) off northwest Australia ...

The probable sources of some of the famous Indian diamonds are the 1.2 Ga old Krishna lamproites of Southern India, a rare Proterozoic occurrence of lamproites which are usually Cretaceous or younger in age. In this study we report Nd, Sr, Pb and Hf isotopes and multiple trace element concentrations of the Krishna lamproites. The goals are to evaluate mantle-processes and the petrogenesis of th...

a State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China b School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK c Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China d College of Earth Sciences, Jilin University...

Abstract Understanding the processes of subducted sediment recycling in subduction zones is vital to decipher Earth’s crust-mantle interactions. This study uses along-arc geochemical variations and zircon U-Pb-Hf-O isotopes Quaternary arc basalts andesites on Sumatra Island, Indonesia assess mode zones. The Hf-O inherited zircons near Toba Caldera indicate that some them were derived from terri...

Abstract Generally all orogenic ultrapotassic rocks are formed after melting of metasomatized sub-continental lithospheric mantle via subducted crustal mica-bearing lithologies. Here we present another possible model, based on the study small Stomanovo monzonite porphyry intrusion in Central Rhodope Massif, Bulgaria. The dated at 30.50 ± 0.46 Ma is intruded into voluminous Oligocene (31.63 0.40...

[1] The neodymium isotopic composition of marine precipitates is increasingly recognized as a powerful tool for identifying changes in ocean circulation and mixing on million year to millennial timescales. Unlike nutrient proxies such as dC or Cd/Ca, Nd isotopes are not thought to be altered in any significant way by biological processes, and thus they can serve as a quasi-conservative water ma...