International Journal of Geosciences, 2016, 7, 378-396 Published Online March 2016 in SciRes. http://www.scirp.org/journal/ijg http://dx.doi.org/10.4236/ijg.2016.73030 How to cite this paper: Yaseen, I.A.A.B. (2016) Petrography, Geochemistry and Petrogensis of Basal Flow from Ar-Rabba Area, Central Jordan. International Journal of Geosciences, 7, 378-396. http://dx.doi.org/10.4236/ijg.2016.73030 Petrography, Geochemistry and Petrogensis of Basal Flow from Ar-Rabba Area, Central Jordan Ibrahim Ahmad Ali Bany Yaseen Institute of Earth and Environmental Sciences, Water, Environment and Arid Regions Research Centre, Al al-Bayt University, Mafraq, Jordan Received 17 February 2016; accepted 27 March 2016; published 30 March 2016 Copyright © 2016 by author and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Thirty basaltic rock samples collected from a central Jordan at Ar-Rabba area were studied. The samples cover about 20 km 2 from the Al-Rabba basalt flow. The Al-Rabba Basalt (RB) introduced Miocene to Pleistocene period. Petrography, Geochemistry and Petrogenesis investigations were carried out for the RB. The petrography analyses of the RB rocks are composed of plagioclase, py- roxene, olivine, opaque minerals (magnetite), and including secondary minerals calcite, idding- site, and clay. The RB rocks have low range of major and trace elements concentrations, and under sodic alkaline magma series. The geochemical analysis data of RB indicated that RB was derived from a slightly fractionation magma as reflected by high MgO concentration range between (5.4 to 11.7 wt%), and Mg number from 42 to 63.8, and high concentration Cr (18 - 385 ppm), Ni (160 - 364 ppm) and low silica content ( 41.79 - 49.87 wt%). The chemical classification of RB is divided into basaltic, calc-alkaline to alkali basalt. The tectonic setting of RB is explained by using dis- crimination diagrams, Ti-Zr-Y, Ti-Zr-Sr and MgO-FeO(tot) -Al 2 O 3 , the RB plotted within the plate, calc-alkali and continental basalt respectively. The Rayleigh fractionation equation modeled for Sr and Ba vector diagram indicated the RB had fractionation for clinopyroxene, orthpyro-xene, oli- vine and trace of plagioclase. Keywords Calc-Alkaline Basalt, Fractionation, Tectonic Setting, Ar-Rabba, Jordan 1. Introduction The regional structures of the region as a result to the tectonic evolution of the Arabian plate which includes the