The Mont Shefford alkaline complex of southern Quebec contains mafic rocks and both silica-oversatwated and -undersaturated syenites. Chemical and isotopic studies examine the relationship of the various lithologies. Isotopic, major, and trace-element compositions are consistent with derivation of all Iithologies from a common mafic paren! some of which evolved to a syenitic itage by fractional...

Abu Hamamid (AH) Neoproterozoic (Sm/Nd model age of 770 ± 20 Ma) mafic–ultramafic intrusion lies along a NE–SW fracture zone in the Shadli Metavolcanic Belt, south Eastern Desert, Egypt. AH intrusion is concentrically zoned with cumulate clinopyroxenebearing dunite core mantled by olivine clinopyroxenite, hornblende clinopyroxenite and hornblende gabbroic rim. The observed crystallization seque...

The central part of the Fennoscandian Shield in Finland is composed of the Palaeoproterozoic Svecofennian domain and the Archaean Karelian craton with a Palaeoproterozoic allochthonous and autochthonous cover. A cryptic suture separating these areas and another tentative suture dividing the Svecofennian into central and southern parts have been proposed. The chemical composition of sedimentary ...

Inclusions of quenched mafic magma occur in a 21 Ma rhyolite lava and precursory non-welded tuff that form the Spor Mountain Formation in west-central Utah. The mafic inclusions are not lithic inclusions; no comparable volcanic unit was present at the surface when the Spor Mountain Formation erupted. Mineral and bulk compositions preclude liquid immiscibility. The mafic inclusions show clear mo...

The titanium concentrations of 484 zircons with U-Pb ages of *1 Ma to 4.4 Ga were measured by ion microprobe. Samples come from 45 different igneous rocks (365 zircons), as well as zircon megacrysts (84) from kimberlite, Early Archean detrital zircons (32), and zircon reference materials (3). Samples were chosen to represent a large range of igneous rock compositions. Most of the zircons contai...

study area is located in district of bajestan and ferdows cities, ne of iran. structurally, this area is part of lut block. the oldest exposed rocks, to the north of intrusive rocks and in eastern bajestan, are meta-chert, slate, quartzite, thin-bedded crystalline limestone and meta-argillite. the sedimentary units are: sardar formation (carboniferous), jamal formation (permian), sorkh shale an...