Abstract
The thick sequence of lava flows and minor pyroclastics constituting the Dokhan volcanics represents an important stratigraphic unit in the Precambrian of Egypt; the term Dokhan Formation is assigned to these rocks. At Jabal Dokhan, the volcanics (1200 m thick) are petrographically classified into andesite, quartz andesite (including the Imperial Prophyry), dacite, quartz latite, rhyodacite, quartz trachyte and pyroclastics. This nomenclature is also supported by the Niggli values, as calculated from 48 new total rock analyses. The minor and trace element distributions (P, Ti, V, Cr, Mn, Co, Ni, and S) were studied for the same samples. The Imperial Porphyry is characterized by appreciable amounts of piemontite and basaltic hornblende, the former is formed by the alteration of both plagioclase and basaltic hornblende through the effect of Mn-rich hydrothermal solutions.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call