The comagmatic volcanic and plutonic rock units along Wadi Abu Marawat, Central Eastern Desert, Egypt: Petrological and Geochemical evidences

The basement rocks of Abu Marawat area comprise talc-carbonates (oldest), metavolcanics and their equivalentpyroclastics, intrusive metagabbro- diorite complex, synkinematic granitoids, Hammamat sediments and basic- ultrabasic intrusion (youngest).Talc-carbonates are represented by lensoidal bodies technically incorporated in the metavolcanics. The metavolcanics comprise basalts, andesite and subordinate dacites together with their equivalent pyroclastics, they were regionally metamorphosed up to the greenschist fades. The metavolcanic suites are of Island arc setting where meta-basalts are of tholeiitic affinity, while the meta-andesites and meta-dacites are of calc-alkaline character. The meta-gabbro-diorite complex is made up of meta-gabbros, diorites and qartz diorites, whereas the synkinematic granitoids are formed of tonalites and granodiorites. The meta-gabbroic and granitoid rocks are of I- type, calc-alkaline affinity and were formed in arc tectonic setting. They are enriched in LIL elements and depleted in Nb and HFS elements, a characteristic feature of subduction related magmatism. The regular variation trends among the major and trace elements as well as the coincidence of the plotted samples favor the assumption that they are comagmatic and formed by processes such fractional crystallization