dyke swarms emplacement constitutes one of the conspicuous features of the neoproterozoic arabian-nubian shield (ans) (~950-540ma). based on field investigations, petrographic and geochemical characteristics the dyke swarms in nw sinai (egypt) comprise of mafic (dolerite-trachy-basalt-basalt), intermediate (basaltic-andesite trachy-andesite) and felsic (rhyodacite-rhyolite) varieties. geochemic...

There have been presented the results of study a thick (no less than 2–3 km), extended (for more 200 km) volcanogenic formation (Tsetsen-Uul or Yargait) in south Zavkhan terrane Central Asian fold belt. The is an assemblage frequently intercalating effusive rocks subalkaline basalt-andesite-dacite-rhyolite series, their tuffs, tuffites, ignimbrites, and terrigenous rocks. Felsic dominate over b...

bouin- miandasht granitoid pluton (bmgp), which outcropped to the north of bouin-miandasht- aligoudarz road, was emplaced into low to medium grade of triassic to early jurassic metapelitic rocks of sanandaj-sirjan structural zone. in this study we do provide the first investigations of bmgp by means of anisotropy of magnetic susceptibility (ams). most km values for the main felsic compositions ...

The late Precambrian Shadli Metavolcanics of SE Egypt constitute a slightly metamorphosed bimodal sequence that has been previously interpreted as manifesting volcanic activity at an island arc. We report the first Rb-Sr geochronologic, trace element (including REE), and Nd isotopic data for these rocks. Two types of basalt are recognized, the stratigraphically lower suite having compositions l...

Apatite minerals of I-type Zouzan granitoids and typical garnet-bearing S-type granites have been analyzed by electron microprobe to define trace element concentrations and compare them in different granites. Zouzan granites are composed of apatites with lower Fe, Mn, Na and HREE and higher REE and ∑REE relative to S-type ones. Trace elements abundances of apatite often vary with some parameter...