The Tectnostratigraphy evolution of the Late JurassicCretaceous in the Zagros Basin

The Zagros Basin is covering the northeastern margin of the Pan-African plate, which host the world largest oilfields. The Jurassic and Cretaceous tectonic events have highly affection on this thrust and fold belt. The main goal of this article is to address the so called events and their influences on sedimentation style and oil habitat of the study area.Based on global geo-dynamic studies, a narrow Ocean (Southern Neo-Tethys) may have been opened along the northern and eastern margins of the Pan-African Plate and rifting away of a narrow micro-continent or series of continental fragments (Iranian micro-plates) in the late Tithonian (Late Jurassic). In addition, a vigorous southeast-ward motion of the India and its separation from the Pan African Plate has been happened in the Late Jurassic to Valanginian (Early Jurassic). Both events led to NE NW ward extensional deformation within the Late Jurassic-Early Cretaceous Zagros Basin. Furthermore, a compressional phase is reported in late Cenomanian-middle Turonian. This tectonic event is known regionally as the Cretaceous deformation with NW-SE Shmax (possibly in Oman, SE margin of the Pan-African) and expressed as the regional Middle Turonian Unconformity which led to the reactivation of normal faults in the Jurassic level, the formation of dominantly transtensional faults in the Cretaceous strata. The NE margin of Pan-African Plate also has been suffered SW-ward compressional forces due to Intra-oceanic subduction within the Neo-Tethys (partial closure of the Southern Neo-Tethys). The Late Jurassic-Early Cretaceous extensional regime is considered as main reason for creation or reactivation of conjugate NW-SE NE-SW normal faults controlling the edge of Jurassic-Early Cretaceous Gotnia-Garau basin and the neighbouring Surmeh-Fahliyan platform. This basin was suitable location for deposition of two major source rocks (Sargelu and Garau) to feed the Jurassic Surmeh/Arab and Lower Cretaceous Fahliyan/Yamama reservoirs. The late Cenomanian-middle Turonian event changed the depositional setting from carbonate ramp into a wide-spread shelf that the Cenomanian (as a wellknown Sarvak/Mishrif reservoir rock in the Middle East) strata has been deposited on this shelf with domination of a rudist benthic foram facies.