Facies analysis and sequence stratigraphy of lower-middle Miocene Euphrates formation (WadiHajar), West of Iraq

Subject Areas : Stratigraphy

Muthana  Al-Tharb ¹ (Deptrtment of Applied Geology, Faculty of Science. Tikrit University. Tikrit. Iraq.)
Abdulhameed  Al-Hadaithy ² (Deptartment of Applied Geology, Faculty of Science. University of Anbar. Anbar, Iraq.)
Furat  Al-Musawi ³ (Deptartment of Geophysics, College of Remote Sensing and Geophysics, Alkarkh University of Science. Baghdad, Iraq.)
Amer  Al-Jibouri ⁴ (Deptartment of Applied Geology, Faculty of Science. University of Anbar. Anbar, Iraq.)

Received: 2022-08-27 Accepted : 2023-04-03 Published : 2023-07-01

Keywords: sequence stratigraphy, Facies Analysis, microfacies, Euphrates, Iraq,

Abstract :

The section located in WadiHajar, Haditha area, west of Iraq was sampled for microfacies analysis of the Euphrates Formation. Microfacies analysis led to the recognition of eleven microfacies association types; Mudstone, Peloidalgrainstone, ooidsgrainstone, Miliolids-Peneroplidsgrainstone, Peneroplidsgrainstone, Echinoidalwackestone, Miliolidswackestone, Alveolinidswackestone, Bioclasticpackstone, Peneroplidspackstone and Rotaliidspackstone, were deposited in restricted marine, shoal, and open marine environments. The study of the vertical succession of microfacies shows four primary 4th order cycles (1, 2, 3, and 4) each show a different episode of stills tands sea level rises. Cycle 1 is represented by LST of basal conglomerate followed by a thick succession of open marine facies of TST, overlain by sh0rt episode of still stand. According to minor sea level changes, cycle 2 is subdivided into 2a, 2b, and 2c consisting TST of bioclastic, miliolids, peloidswackestone to packstone, followed by thin HST consisting restricted marine facies. Cycle 3 consists of a short episode of sea level rise of TST followed by a long episode of sea level still standing and subdivided into 3a and 3b. Cycle 4 is marked by open marine facies (TST), overlain by HST of restricted marine facies. The low subsidence rate and eustatic sea-level fluctuation are the main factors that affect the study area.

References:

1. Abid AA (1997) Biostratigraphy and Microfacies of the Late Oligocene–Middle Miocene formations, Central and North Iraq. Unpublished PhD thesis, University of Baghdad, Iraq, 258p.


2. Ahr WM (1989) Sedimentary and tectonic controls on the development of an early Mississippian carbonate ramp, Sacramento Mountainarea, NewMexico. In: Crevello DP,Wilson LJ, Sarg FJ and ReadFJ(eds) Controls  on  carbonate  platform  and  basindevelopment. Soc Econ Paleontol Miner Spec Publ.


3. Al-Dabbas M (2014) Facies analysis and geochemistry of Euphrates Formation, Central Iraq .Arab Journal of Geosciences 7(5): 1799-1810.


4. Al-Ghreri MF (2007) Biostratigraphic succession of the formations of Euphrates valley between Hit and Al-Qaim in Iraq, PhD thesis, University of Baghdad, Iraq, 121p.


5. Al-Ghreri MF, Al-Bakkal KK (1993) Sedimentological and paleontological study of Oligocene–Miocene boundary basal conglomerates unit in west Iraq. Journal of Science Nature 2(1): 22–27.


6. Al-Ghreri MF, Al-Jibouri AS, Al-Ahmed AA (2014) Facies architecture and sequence development of the Euphrates formation  in western Iraq, Arabian Journal of Geosciences 7(7): 2679–2687.


7. Al-Ghreri MF, Sayyab AS, Jassim JA (2010) Remarks on the age of the Miocene Euphrates formation, Western Iraq Proceeding of the Fifth Scientific Environmental Conference. Zagazig University, Egypt. 185–195.


8. Al-Hetty SO, Al-jibouri AS, Abid AM (2021) Description of the Karst Phenomena Spreading AlongStratified Sequence in the Western Desert of Iraq. Iraqi Geological Journal23:94-101.


9. Al-Mubarak M (1974) The regional geological mapping of upper Euphrates valle, GEOSURV, internal report. No. 673,


10. Al-Sayyab AS, Jassim AJ, Al-Ghreri MF (1988) Biostratigraphy of the Euphrates formation ( Early Lower Miocene-Middle Miocene) in its type locality. Journal of Geology Society21 (2): 12-27.


11. Awadh SM, Al-Ankaz ZS (2016) Inorganic geochemistry and origin of bitumen intruded in Euphrates and Fatha Formations in Hit area, Western Iraq. Iraqi journal of Science 57(4A): 2478-2489.


12. Awadh SM, Al-Qwaidi MR (2020) Application of triangles method for quantitative estimation of marl reserve in Euphrates Formation, Middle of Iraq. Iraqi Geological Journal53(2A): 35-49.


13. Bandy OL (1961) Distribution of foraminifera, radiolarian and diatoms in sediments of the Gulf of California. Journal of Micropaleontology 7(1):1–26.


14. Bayan MH (2010) Hydrogiologic Conditions within Al-Anbar Governorate. Journal of University of Anbar for pure science 4 (3): 1 – 15.


15. Buday T (1980)The regional geology of Iraq, Vol.1, Stratigraphy and paleogeography: Dar Al-Kutub Publishing House, University of Mosul, Mosul, Iraq, 445 pp.


16. BudayT, Jassim SZ (1987) The Regional Geology of Iraq. Vol.2: Tectonism, Magmatismand Metamorphism. State Establishment of Geological Survey and Mineral Investigation, Baghdad, Iraq, 352pp.


17. Dunham RJ (1962) Classification of carbonate rocks according to depositional texture, In: Ham, W. E. (Ed.).Classification of carbonate rocks: American Association of Petroleum Geologists Memoir.


18. Flügel E (1982) Microfacies analysis of limestones. Springer, Berlin, 633 pp.


19. Flügel E (2004) Microfacies of carbonate rocks. Analysis interpretation and application, Springer, Berlin, 976 pp.


20. Fouad SFA (2007) Tectonic Geology of the Iraqi Western desert “tectonic and structural evolution”. Iraqi Bulletin of Geology and Mining, special issue2007:29-50.


21. Geel T (2000) Recognition of stratigraphic sequences in carbonate platform and slope deposits: empirical models based on microfacies analysis of Palaeogene deposits in southeastern Spain, Palaeogeography, Palaeoclimatology,Palaeoecology 155: 211–238.


22. GhasemShirazi B, Bakhshandeh L, Yazdi A (2014) Paleoecology of Upper Cretaceous Sediments in Central Iran, Kerman (Bondar- e Bido Section) Based on Ostracods. Marine Science 4 (2): 49-57


23. Hottinger L (1997) Shallow benthic foraminiferal assemblages as signals for depth of their depositionand their limitations. Bull SocGéolFr 168(4):491–505.


24. Multer HG (1977) Field guide to some carbonate rock environments. Florida keys and westernBahamas 415p.


25. Sissakian VK, AI Amin RM, Salman BM (1997) The Nfayil formation: a new lithostratigraphic unit in the Western Desert of Iraq. Iraqi Geological Journal 30(1): 61–65.


26. Tucker ME (2001) Sedimentary petrology: An Introduction to the Origin of Sedimentary Rocks.  3rd edBlackwell Publishing Co. 262.


27. Tucker ME, Wright VP (1990) Carbonate Sedimentology: Black well, Oxford, UK, reprinted 2002,482p.


28. Wilson JL (1975) Carbonate facies in geological history springer-verlag,Berlin, 475p.