Contribution to the petrography, geochemistry, and tectonic setting of the basalt flows of the Umm-Qais plateau, north Jordan

Authors : H. El Akhal

Pages : 1-12

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Publication Date : 2004-02-01

Article Type : Research

Abstract :The Umm-Qais plateau is situated in north Jordan, south of the Yarmouk River. It consists of eleven  basalt flows (about 190 m. thickness). The basalt flows belong to the Arabian Harrat volcanism. Petrographical,  mineralogical and geochemical analysis of 11 rock samples indicated that the rocks are products of a continental  intra-plate magmatism, mostly as coarse-grained silica-undersaturated olivine-rich alkali basalt (AOB).  Nepheline and Fo-olivine are among the normative minerals. The age of the basalt flows can be correlated with the basalt of the northern extension of the Umm-Qais  plateau north the Yarmouk River (Zamlat Bkhila plateau basalt) in the Golan Heights which was found to be  3.7±0.36-3.11±0.16 Ma. Flow eruptions are contemporaneous with the second spreading stage of the Red Sea  during the Cainozoic over the past 5 Ma. Analysis of fractures showed mainly four dominant directions, namely ENE/WSW, NW/SE, NNE/SSW  and NE/SW. They coincide with the trends of the Red Sea, Dead Sea transform fault, and some other distinct tectonic  features.
Keywords : North Jordan