The Drowned Arabian Carbonate Platform and Associated Phosphate Deposits, Coniacian- Campanian, Mardin-Mazidag Area, SE Turkey
The studied successions take place within the Karabogaz Formation and unconformably overlie the dolostones of the Derdere Formation on the Mazidag area between Diyarbakir and Mardin city, SE Turkey. There is a gray-green colored claystone/mudstone with a 5–10 cm thickness over the reddish-yellowish oxidized surface of the unconformity penetrating 10–40 cm into the underlying dolostones. Overlying next layers composed of mudstones characterized by abundant marine fish remains, teeth and bones, phosphate fragments, oncoids, bioturbations and glauconites. The middle to upper part of the succession includes clayey limestones with decreasing fish remains and phosphate fragments. In the middle part of the section, alternation of marn and clayey limestones continues towards the top of the succession and includes some vertebrate bones. A relatively thin shelled bivalve abundance can be seen near the top of the succession. At the top, there are chert nodules within clayey limestones including fish remains, solitary sponge molds and fragments. Overlying successions include bioturbated bioclastic limestones, silicified thick-bedded ostrea coquina limestones, and thin bedded limestones. This succession transgressively overlies the exposed and karstified carbonate platform in the northern Arabian Plate, and and pelagic deposits including phosphate nodules and oncoids, glauconites and fish remains cover the unconformity surface after a sudden drowning. Over the Karabogaz formation, Campanian-Maastrichtian aged pelagic successions composed of marls, shales and limestones including planktonic forams, plant fragments, innoceramus and ammonites take place. This succession belongs to Lower Germav Formation in the region. The pelagic facies with abundant shark remains and phosphate deposits on the drowned platform may be used as a key horizon on the this part of the Arabian platform and can indicate a sudden rise of tectonically controlled sea level, increase of nutrient due to upwelling currents and oceanic connection.
AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014