Boninites are unusual island arc volcanic rocks with high MgO (>9%), high Si0 2 (>55%) contents, and exceptionally low TiO 2 (<0.4%) contents. High MgO contents, MgO/(MgO + EFeO), Ni, Cr and Co contents indicate that boninites have equilibrated with mantle peridotite. Experimental petrologic studies and high Cr/(Cr + Al) in spinels in boninites suggest that they have separated from extremely re...

Investigations have been undertaken to provide constraints on the nature of geochemically active processes in the mantle and their effects on mantle evolution and magma generation. Three types of approaches have been implemented: (1) To study isotopic systematics and trace element abundances in young, mantle-derived volcanic rocks, which, because of their tectonic setting, had little or no chan...

To elucidate the influence of airborne materials on the ecosystem of Japan's Yakushima Island, we determined the elemental compositions and Sr and Nd isotope ratios in streamwater, soils, vegetation, and rocks. Streamwater had high Na and Cl contents, low Ca and HCO(3) contents, and Na/Cl and Mg/Cl ratios close to those of seawater, but it had low pH (5.4 to 7.1), a higher Ca/Cl ratio than seaw...

Lunar Mg-suite norite 78238 was dated using the Sm–Nd, Rb–Sr, and U–Pb isotopic systems in order to constrain the age of lunar magma ocean solidification and the beginning of Mg-suite magmatism, as well as to provide a direct comparison between the three isotopic systems. The Sm–Nd isotopic system yields a crystallization age for 78238 of 4334 ± 37 Ma and an initial e Nd value of 0.27 ± 0.74. T...

In this article, we examine a broad sample of socially responsible (SR) and conventional mutual funds with respect to nancial and ethical parameters. We cannot document profound differences in their nancial performance. With regard to ethical performance, we indeed nd that an investor who seeks to avoid the least ethical of all available funds can do so by purchasing SR mutual funds. Still, we ...

In order to characterize the provenance of lithogenic surface sediments from the Eastern Mediterranean Sea (EMS), residual (leached) fraction of 34 surface samples have been analysed for their Nd/Nd and Sr/Sr isotope ratios. The sample locations bracket all important entrances of riverine suspended matter into the EMS as well as all sub-basins of the EMS. The combined analyses of these two isot...

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...

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...