Geochemistry and geotectonic setting of neoproterozoic granitoids from Artoli area, Berber Province, northern Sudan

The research aimed at deciphering the genetic relationship of the Artoli area, Berber Province, Northern Sudan with the domains of Saharan Metacraton and Arabian Nubian Shield and tries to define the boundary between them. In order to determine the tectonic environment, the petrographic characteristics and the original protoliths of granitoid rocks occurring within the area, several discrimination and variation diagrams were constructed using their whole-rock geochemical analysis and integrated with field observations and petrographic investigations. The results revealed that the rocks constitute voluminous, intermediate to acidic granitoidal batholith of granodiorite, quartz-diorite and diorite with lesser amount of granite that emplaced in a crystalline Proterozoic basement complex, comprising of low-grade schistosed metavolcanic rocks and minor high-grade metasediments. The Artoli granitoids are identified as medium-to high-K, calc-alkaline, metaluminous and I-type granitoid suite emplaced as volcanic arc granites above a Noeproterozoic subduction zone during the syn- to late-collision stages of crust evolution. The magmas of these granitoids were derived from the mantle with involvement of minor crust components. The overall geological and geochemical characteristics of the Artoli granitoids are comparable to the plutonic rocks of the Arabian-Nubian shield in Arabia, Egypt and NE Sudan. Thus, the area considered as a part of the westernmost Nubian Shield with its boundary with Saharan Metacraton lying further west. © 2011 Asian Network for Scientific Information.