PALYNOMORPH BIOSTRATIGRAPHY OF THE SUBSURFACE DEVONIAN ROCKS, GHAZALAT BASIN, WEST QATTARA DEPRESSION, EGYPT

Abstract

Well–preserved palynomorphs dominated by miospores and subordinate acritarchs and chitinozoans are recovered from some cuttings of Ie 11 2 borehole drilled in the Ghazalat Basin in the west of Qattara depression, Egypt . A total of 36 species of palynomorphs (25species of spores, 8 species of acritarchs and 3 chitinozoan species) are identified. The palynological investigation of the studied stratigraphic interval enabled the recognition of three informal zones ranging in age from Lochkovian to Emsian. Most of the palynomorph taxa encountered are closely comparable with coeval assemblages recorded from North Africa, Saudi Arabia, Western Europe and Canada, indicating the close relationship of the present area to other parts of the western Gondwana and southern Euramerican provinces during that time interval. Frequent representation of marine taxa (acritarchs and chitinozoans) together with associated spores indicate near-shore marine depositional environment for the Lower and Middle Devonian (Zeitoun Formation) deposits in north Western Desert region of Egypt. Keyword: Devonian; palynomorphs biostratigraphy; Ghazalat Basin; West Qattara Depression.