The Precambrian rocks in western Ethiopia consist of highand low-grade terranes intruded by granitoids with a wide compositional spectrum. The formation ages of these granitoid rocks are, so far, poorly understood. Single-grain zircon Pb/Pb evaporation and conventional U/Pb dating conducted on four granitoids places time constraints on their emplacement and tectonothermal events. Three granitoi...

Article history: Received 6 October 2016 Accepted 29 January 2017 Available online 08 February 2017 Widespread Late Triassic granitoid rocks in the SouthQinling Belt (SQB) represent excellent subjects to study the geochemical and geodynamic evolution of magmatic rocks during the collision between the North China Craton and South China Block. In this study, we report new geological, geochemical,...

The rocks of the Wadi Umm Gheig/El-Shush area in the central Eastern Desert of Egypt form part of the Nubian Shield, a component of the Neoproterozoic Pan-African Orogeny. The rocks have been divided into three units: (i) low-grade metamorphosed rocks, which consist of metavolcanic rocks interleaved with slices of ophiolitic melange; (ii) high-grade metamorphic rocks, which consist of syn-tecto...

Modelling the groundwater contamination in the aquifer above a repository for high-level nuclear waste is a complex task. The usual procedure is based on modelling the transport of radionuclides in one or two dimensions only (NAGRA, 2002; Kosakowski, 2004; Keesmann et al., 2006; SKB, 2006; Nykyri et al., 2008). However, modern computing techniques allow to perform simulations in three dimension...

[1] A unique spectral component has been identified near and on the central peaks of two 30 km diameter craters in northern Syrtis Major. These exposures are clearly visible in Thermal Emission Imaging System (THEMIS) color radiance images as well as THEMIS and Thermal Emission Spectrometer (TES) surface emissivity data. Both TES and THEMIS data indicate the presence of increased 1050–1250 cm 1...

A model for the formation of granitoid systems is developed involving melt production spatially below a rising isotherm that defines melt initiation. Production of the melt volumes necessary to form granitoid complexes within 10(4)-10(7) years demands control of the isotherm velocity by melt advection. This velocity is one control on the melt flux generated spatially just above the melt isother...

We recognize eight types of ferroan granitoid that can be distinguished on the basis of major element chemistry.These include alkalic granitoids that may be metaluminous or peralkaline, alkali-calcic granitoids that may be metaluminous, peraluminous or peralkaline, calc-alkalic granitoids that may be metaluminous or peraluminous, and rare calcic ferroan granitoids. These granitoids may form by ...