Sandstones Petrography of the Devonian Zakeen Formation, Southern Iran
A sequence of the Devonian clastic sediments (Zakeen Formation) at 103 km north of Bandar-Abbas, south of Iran was studied. This study has been done to determine the clastic size, petrofacies and roundness variations throughout the lithological column of the Zakeen Formation. The Devonian sediment in Iran is a new prospect for gas exploration. The Zakeen Formation can be correlated to the Devonian gas-bearing formations (Tawil, Jauf and Jubah) of Saudi Arabia. Clean sandstone have been frequently found in Lower half of this Formation but in upper half winnowing of sandstone decreased and sedimentary structures of shallow marine environments such as flaser bedding and cross-stratification are less frequent. The Zakeen sandstones are much cleaner than that of sandstones of Tavil,Jauf and Jubah formations. Six petrofacies such as Arkosic arenit,Subarkose,Quartz arenite,Siltstone,Dolomite and Shale have been recognized. Investigation on sandstone samples indicated that arkosic arenite is outstanding in upper half, caused increases of feldspar toward top. Measured roundness of the most sandstones of the Zakeen Formation is in sub rounded realm and the least frequent type is sub angular. Measurement of clastic size throughout the lithological column of this Formation indicates a fining upward trend which corresponds to the fact that muddy continental shelf facies frequently has been found in upper part .The greatest size of quartz and feldspar belongs to sub-tidal sand wave facies. Some quartz grains of this Formation inherited an eroded quartz overgrowth rim which indicates presence of recycled grains in the sandstone.
Permo-Carboniferous (Classic Gondwana) Basins and Reservoirs
2006 AAPG International Conference and Exhibition, (November 5-8, 2006) Technical Program