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 ...

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...

The early Proterozoic Taltson Magmatic Zone (TMZ) comprises the southern part of the Taltson-Thelon orogenic belt of northwestern Canada. The TMZ is dominated by 1.96–1.99-Ga I-type and 1.93–1.95-Ga S-type suites of granitoids. Previous workers attributed the formation of the I-type granitoids to subduction of oceanic crust beneath the Churchill craton in an Andean-type setting, and generation ...

Many of the late Paleozoic granitoid plutons of the southern Appalachians are composite bodies with coarsegrained amphibole + biotite and biotite varietal facies (Speer et al., 1980). From field relations, these facies appear closely related, and multiple intrusion or differentiation comes to mind as an explanation for the relationship. In the Liberty Hill pluton, the coarse-grained central amp...

The Papuk Mt. belongs to the Slavonian Mountains in Croatia. It is situated in the southernmost part of the Tisza Megaunit (Fig. 1). Comprehensive reviews of the geological setting of this area are given by JAMIČIĆ & BRKIĆ (1987), JAMIČIĆ (1989) and KOROLIJA & JAMIČIĆ (1989). VRAGOVIĆ (1965) gave a detailed petrographic description of the gneisses, granitoids and the pegmatites of this region. ...

Two crustal-scale shear zone systems, the Storsjön–Edsbyn deformation zone and the Hassela shear zone join in the western part of central Sweden and form an anastomosing pattern of ductile shear zones. Several of these, up to 1 km wide, zones truncate an intrusion previously defined as a component of the major, ca. 1.80–1.77 Ga magmatic suite (the Revsund granitoids) in north central Sweden. Ho...

Five calc-alkaline plutons; Um Tagher, Abu Zawil, Um Gidri, Um Anab and El Ghuzah, in the northern Eastern Desert of Egypt were subjected to petrographic and mineralogical investigations. They are composed of varying proportions of quartz + plagioclase +potash feldspar+ biotite + hornblende± epidote ± calcite + titanite +magnetite + apatite and zircon. Electron microprobe analyses of coexisting...