Surface and sub-surface study to interpret the paleo basin morphology during Hauterivian-Albian in Kurdistan Region and North-Iraq
Sirwan H. Ahmed1*, Amanj I. Qaradaghi1 & Aram N. Tofiq1
1 Geology Department, University of Sulaimani, 1838, New campus, Bakhibakhtiary, Sulaimani, Iraq
Article infoOriginal: 06.10.2015
The depositional basin shape configuration and evolution of western flank of the Neo-Tethys can be modelization during Hauterivian-Albian depends on (1) detail study of the outcrops in Northeastern Kurdistan and (2) seismic interpretation in the south and western of Kurdistan-Iraq. During Hauterivian-Albian, the Kurdistan was a path through series basin changes. Lateral and vertical facies changes are directly related to the (1) final active rifting phase of the Tethys and (2) the Kurdistan was located on the western margin of the depositional basin. During Hauterivian-Barremian, the northwestern flank of the Tethys extends to the extreme northwestern of Iraq. The distribution facies of shallow clastic (Zubair Formation) in the west inner-shelf facies in the center (Garague Formation), outer-shelf Lower Sarmord Formation in the northeast of Kurdistan and deep open-sea Balambo Formation in the extreme east of Kurdistan indicate the gentle sloping of the Tethys. No exist (1) shallow facies between deep-facies, (2) Shallow to deep facies change step by step regularly and (3) no any large scale extensional Syn-depositional faults in the seismic lines are clearly indicate no any active graben formed during this period. Consequently during Hauterivian-Berriasian most possibly the rift of the Tethys was slow. The Aptian-Albian period is the time of development the reefal platform that formed among deep-open sea and outer-shelf in the east and west consequently. The N-S longitudinal large Qamchuqa Platform well developed with the final opening of the Tethys. The Qamchuqa platform is the factor in terminating the Hauterivian-Barremian outer-shelf and changed into the shallow basin in the west and deep opens sea in the East. The fast vertically and laterally facies change without any interruption of deposition indicate the active period of N-S extension faults corresponding to the Tethys rifting. During Albian, the continuous development of the Qamchuqa reefal platform and deep-open-sea in the east indicate nearly same situation as much as Aptian time. But in the northwest and west, the dominant marly facies of Upper Sarmord Formation developed that is deeper than shallow Shuaiba and Nahr Omer formations. From the Seismic line and interpretation, we clearly identified the NW-SE trend graben in the Kirkuk and Mosul area. Occur of the graben nearly perpendicular to the main Qamchuqa reefal indicating of the development of the NW-SE trending extension fault as a result of the flexibility of the Arabian Plate between final steps of rifting and initiating the Arabia-Eurasia obduction event.