Dolomitization of the Lower Part of the Sargelu Formation, Northeastern Iraq
Article Sidebar
Main Article Content
Abstract
The prominent characteristic of the lower part of the Sargelu Formation of the Middle Jurassic is the occurrence of destructive dolomitization. This dolomitized unit, cropped out in the high folded and Imbricated zones in Northern Iraq, is situated in the Gotnia Basin and has been distinctly identified and are documented in previous studies. Dolomite crystals are euhedral in shape; hence, they are classified as saccharoidal dolomite, resulting in the elimination of all biocontent and the destruction of the original rock fabrics. Despite the abundance of intercrystalline pores in this unit and their role in the quality of reservoirs in the oil fields, the origin or mechanism of dolomitization is not well understood yet. The aim of this investigation is to find out a suitable model for the dolomitization and to propose possible mechanisms that led to the dolomitization. At the top of the Lower Jurassic Sehkaniyan Formation, an extensive mass of destructive dolomitization has also occurred. The dolomitic unit of the Sargelu Formation, which extends for hundred kilometers constantly. Stratigraphic correlation reveals that the Sargelu Formation is juxtaposed with different successions, such as the Alan and Sehkaniyan formations, that show evidence about peritidal and sabkha environments, where the dolomitization units were associated with solution collapse breccia and microbial stromatolite. This study proposes that the reflux and burial dolomitization models for the lower part of the Sargelu Formation by comparing the paleoenvironmental conditions of the late Lower Jurassic and early Middle Jurassic in the Gotnia basin with a modern analogue model.
Article Details
This work is licensed under a Creative Commons Attribution 4.0 International License.
Tikrit Journal of Pure Science is licensed under the Creative Commons Attribution 4.0 International License, which allows users to copy, create extracts, abstracts, and new works from the article, alter and revise the article, and make commercial use of the article (including reuse and/or resale of the article by commercial entities), provided the user gives appropriate credit (with a link to the formal publication through the relevant DOI), provides a link to the license, indicates if changes were made, and the licensor is not represented as endorsing the use made of the work. The authors hold the copyright for their published work on the Tikrit J. Pure Sci. website, while Tikrit J. Pure Sci. is responsible for appreciate citation of their work, which is released under CC-BY-4.0, enabling the unrestricted use, distribution, and reproduction of an article in any medium, provided that the original work is properly cited.
References
[1] Buday, T. (1980). The regional geology of Iraq: stratigraphy and paleogeography (Vol. 1). State Organization for Minerals, Directorate General for Geological Survey and Mineral Investigations. [2] Balaky, S.M.H. (2004). Stratigraphy and sedimentology of Sargelu Formation (Middle Jurassic) in selected sections in Erbil and Duhok governorates, Iraqi Kurdistan. M. Sc. Thesis, Univ. of Salahaddin, 109p. [3] Saeed, A. (2017). Sedimentology and stratigraphy of the Middle to Upper Jurassic succession of northern Iraq. Unpublished (Doctoral dissertation, Royal Holloway, University of London). [4] Flügel, E., & Munnecke, A. (2010). Microfacies of carbonate rocks: analysis, interpretation and application (Vol. 976, p. 2004). Berlin: springer. [5] Zenger, D.H., Dunham, J.B., & Ethington, R.L. (1980). Concepts and models of dolomitization. SEPM Society for Sedimentary Geology.
[6] Zhu, D., Zhang, D., Liu, Q., Xing, F., He, Z., Zhang, R., & Liu, Z. (2018). Formation mechanism of dolomite reservoir controlled by fourth-order sequence in an evaporated marine environment–an example from the lower Ordovician Tongzi Formation in the Sichuan Basin. Energy Exploration & Exploitation, 36(4), 620-644. [7] Land, L.S. (1980). The isotopic and trace element geochemistry of dolomite: The State of the Art. [8] Warren, J. (2000). Dolomite: occurrence, evolution and economically important associations. Earth-Science Reviews, 52(1-3), 1-81. [9] Machel, H.G. (2004). Concepts and models of dolomitization: A critical reappraisal. Geological Society, London, Special Publications, 235(1), 7-63. [10] Tucker, M.E., Sedimentary petrology: An introduction to the origin of sedimentary rocks. 2001: John Wiley & Sons. [11] Jassim, S. Z., & Goff, J. C. (Eds.). (2006). Geology of Iraq. DOLIN, sro, distributed by Geological Society of London. [12] Fouad, S. F., & Sissakian, V. K. (2011). Tectonic and structural evolution of the Mesopotamia Plain. Iraqi Bulletin of Geology and Mining, special issue, 4, 33-46. [13] Dercourt, J.E.A., Zonenshain, L.P., Ricou, L.E., Kazmin, V.G., Le Pichon, X., Knipper, A.L., ... & Biju-Duval, B. (1986). Geological evolution of the Tethys belt from the Atlantic to the Pamirs since the Lias. Tectonophysics, 123(1-4), 241-315. [14] Faqi, A., Abdullah, B., Bowden, S., & Ali, A. (2018). Source rock evaluation and lateral changes in thermal maturity of the Sargelu Formation (Middle Jurassic) in Kurdistan Region-Northern Iraq. UKH Journal of Science and Engineering (UKHJSE), 2(1), 7-17. [15] Sharland, P.R., Casey, D.M., Davies, R.B., Simmons, M.D., & Sutcliffe, O.E. (2004). Arabian Plate sequence stratigraphy–revisions to SP2. GeoArabia, 9(1), 199-214. [16] Aqrawi, A.A., Goff, J.C., Horbury, A.D., & Sadooni, F.N. (2010). The petroleum geology of Iraq. Scientific press. [17] Al-Husseini, M.I. (1997). Jurassic sequence stratigraphy of the western and southern Arabian Gulf. GeoArabia, 2(4), 361-382. [18] Numan, N.M. (1997). A plate tectonic scenario for the Phanerozoic succession in Iraq. Iraqi Geological Journal, 30(2), 85-110. [19] Wilson, A.O. (2020). Chapter 1 Introduction to the Jurassic Arabian Intrashelf Basin. Geological Society, London, Memoirs, 53(1), 1-19. [20] Bellen, R.V., Dunnington, H.V., Wetzel, R., & Morton, D. (1959). Lexique stratigraphique international. Asie, Iraq, 3(10a), 324. [21] Surdashy, A.M. (1999). Sequence stratigraphic analysis of the Early-Jurassic central and northern Iraq. Unpublished (Doctoral dissertation, Science College, University of Baghdad). [22] Mohialdeen, I.M. (2018). Hydrocarbon generation potential and palynological study of the early Jurassic succession (Alan, Mus, and Adaiyah Formations) in well Miran-2, Sulaimaniyah, Kurdistan region, Iraq. Iraqi Bulletin of Geology and Mining, 14(1), 13-30. [23] Rashid, F. (204820). Reservoir productivity analysis of intercalated limestone and anhydrite beds in Zagros Folded Belt, Kurdistan Region of Iraq. Kurdistan Journal of Applied Research, 5(1), 1-15. [24] Abdula, R.A. (2016). Organic geochemical assessment of Jurassic potential source rock from Zab-1 well, Iraqi Kurdistan. Iraqi Bulletin of Geology and Mining, 16(3), 53-64. [25] Sissakian, V.K., & Mohammed, B.S. (2007). Stratigraphy. Iraqi Bulletin of Geology and Mining, (1), 51-124. [26] Csató, I., Kiss, K., Toth, S., & Varga, M. (2014). Upper Triassic-Jurassic depositional systems in the Akri-Bijeel exploration block, Iraqi Kurdistan. MOL Group Scientific Magazine, 1, 54-71. [27] Abdula, R.A., Balaky, S.M., Nurmohamadi, M.S., & Piroui, M. (2015). Microfacies analysis and depositional environment of the Sargelu Formation (Middle Jurassic) from Kurdistan Region, northern Iraq. Donnish Journal of Geology and Mining Research, 1(1), 001-026. [28] Al-Ameri, T.K., & Al-Nagshbandi, S.F. (2015). Age assessments and palynofacies of the Jurassic oil source rocks succession of North Iraq. Arabian Journal of Geosciences, 8, 759-771. [29] Aqrawi, A.A., & Badics, B. (2015). Geochemical characterisation, volumetric assessment and shale-oil/gas potential of the Middle Jurassic–Lower Cretaceous source rocks of NE Arabian Plate. GeoArabia, 20(3), 99-140. [30] Hussein, H.S., & Abdula, R.A. (2018). Multiple linear regression approach for the vitrinite reflectance estimation from well logs: A case study in Sargelu and Naokelekan Formations–Shaikhan-2 Well, Shaikhan oil field, Iraq. Egyptian journal of petroleum, 27(4), 1095-1102.
[31] J. Al-Atroshi, S.,H. Sherwani, G., & Al-Naqshbandi, S.F. (2019). Assessment of the hydrocarbon potentiality of the Late Jurassic formations of NW Iraq: A case study based on TOC and Rock-Eval pyrolysis in selected oil-wells. Open Geosciences, 11(1), 918-928. [32] Abdula, R.A., Asaad, H.R., Qasim, O.K., Hashmi, H.S. K., & Abdi, B.S. (2020). Volumetric Calculation of Generated Hydrocarbon from Sargelu Formation in Kurdistan Region, Iraq. UKH Journal of Science and Engineering, 4(2), 166-177. [33] Hakimi, M.H., Najaf, A.A., Abdula, R.A., and Mohialdeen, I.M.J., 2018, Generation and expulsion history of oil-source rock (Middle Jurassic Sargelu Formation) in the Kurdistan of north Iraq, Zagros folded belt: Implications from 1D basin modeling study, Journal of Petroleum Science and Engineering, v. 162, pp. 852-872. [34] Abdula, R.A., 2015, Hydrocarbon potential of Sargelu Formation and oil-source correlation, Iraqi Kurdistan, Arabian Journal of Geosciences, v. 8, issue 8, pp. 5845-5868 [35] Abdula, R.A., “Petroleum source rock analysis of the Jurassic Sargelu Formation, northern Iraq,” Master's thesis (unpublished), Colorado School of Mines, Golden, Colorado, June 2010, 106p. [36] Akram, R., Edilbi, A. N., Mamaseni, W. J., Sherwani, G. H., & Al-Ansari, N. (2021). Source Rock Evaluation and 1-D Basin Modelling Approach for the Sargelu Formation, Atrush-2 Well, Kurdistan Region-Iraq. Open Journal of Geology, 11(3), 49-60. [37] Coe, A.L. (Ed.). (2003). The sedimentary record of sea-level change. Cambridge University Press [38] Emery, D., & Myers, K. (Eds.). (2009). Sequence stratigraphy. John Wiley & Sons. [39] Bernoulli, D., & Jenkyns, H. C. (1974). Alpine Mediterranean and central Atlantic Mesozoic facies in relation to the early evolution of the Tethys. [40] Purdy, E.G. (1964). Sediments as substrates. Approaches to paleoecology, 238. [41] Boggs, S. (2009). Petrology of sedimentary rocks. Cambridge university press. [42] Sibley, D.F., & Gregg, J.M. (1987). Classification of dolomite rock textures. Journal of Sedimentary Research, 57(6), 967-975. [43] Meister, P., Mckenzie, J.A., Bernasconi, S.M., & Brack, P. (2013). Dolomite formation in the shallow seas of the Alpine Triassic. Sedimentology, 60(1), 270-291. [44] Melim, L.A., & Scholle, P.A. (2002). Dolomitization of the Capitan Formation forereef facies (Permian, west Texas and New Mexico): Seepage reflux revisited. Sedimentology, 49(6), 1207-1227. [45] Qing, H., Bosence, D.W., & Rose, E.P. (2001). Dolomitization by penesaline sea water in Early Jurassic peritidal platform carbonates, Gibraltar, western Mediterranean. Sedimentology, 48(1), 153-163. [46] Oliver, J. (1986). Fluids expelled tectonically from orogenic belts: their role in hydrocarbon migration and other geologic phenomena. Geology, 14(2), 99-102. [47] Moore, C.H., Carbonate diagenesis and porosity. 1989: Elsevier. [48] Sadooni, F., & Al Awadi, M. (2009). Dolomite: perspectives on a perplexing mineral. Oilfield review, 21(3). [49] Reinhardt, E.G., Cavazza, W., Patterson, R.T., & Blenkinsop, J. (2000). Differential diagenesis of sedimentary components and the implication for strontium isotope analysis of carbonate rocks. Chemical Geology, 164(3-4), 331-343. [50] Xiulian, Z., Yinghua, W., & Xiaolong, C. (2000). Diagenesis and Porosity of the Cambrian‐Ordovician Carbonate Shoal Facies at Yangjiaping, Shimen, Hunan. Acta Geologica Sinica‐English Edition, 74(1), 29-45. [51] Xiulian, Z., & Lingzhi, J. (2001). Research on diageneses of Cambrian shoal facies carbonate rocks in the Xiadong area, Hubei province. Acta Geologica Sinica‐English Edition, 75(2), 161-174. [52] Adams, J.E., & Rhodes, M.L. (1960). Dolomitization by seepage refluxion: American Association of Petroleum Geologists Bulletin, v. 44. [53] Jones, G.D., & Rostron, B.J. (2000). Analysis of fluid flow constraints in regional-scale reflux dolomitization: constant versus variable-flux hydrogeological models. Bulletin of Canadian Petroleum Geology, 48(3), 230-245. [54] Rameil, N. (2008). Early diagenetic dolomitization and dedolomitization of Late Jurassic and earliest Cretaceous platform carbonates: a case study from the Jura Mountains (NW Switzerland, E France). Sedimentary Geology, 212(1-4), 70-85. [55] Makhloufi, Y., Rusillon, E., Brentini, M., Moscariello, A., Meyer, M., & Samankassou, E. (2018). Dolomitization of the Upper Jurassic carbonate rocks in the Geneva Basin, Switzerland and France. Swiss Journal of Geosciences, 111, 475-500. [56] Sharland, P.R., Archer, R., Casey, D.M., Davies, R.B., Hall, S.H., Heward, A.P., ... & Simmons, M.D. (2001). Sequence stratigraphy of the Arabian Plate. GeoArabia, 2(37), 1.