Abstract
Subsurface Cretaceous-Tertiary evaporite samples collected from selected oil boreholes in northern Iraq exhibit complicated diagenetic features that resulted from deep burial and other modifying agents. Among these features are extensive dissolution, growth of larger crystals or laths from preexisting evaporitic groundmass, widespread cementation in both evaporitic and non-evaporitic rocks, and the development of stylolites and fractures. SEM examination of evaporite-carbonate replacive contacts has shown that evaporites replace carbonates in root-like structures that gradually penetrate the carbonate structure following either capillary interstitial spaces or weakness planes. Cretaceous evaporites were deposited mainly in sabkha settings, whereas Tertiary evaporites were formed in salinas and sabkhas.
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ANADON, P., ROSELL, L. and TALBOT, M.R., 1992, Carbonate replacement of lacustrine gypsum deposits in two Neogene continental basins, eastern Spain:Sedimentary Geology, v. 78, p. 201–216.
BORCHET, H. and MUIR, R. O., 1964, Salt deposits- the origin, metamorphism and deformation of evaporite. D. Van Nostrand, London, 338 p.
BRAITHWAITE, P., 1981, Illustrations of different lithologies and reservoir types, West Baghdad area, Iraq. Unpublished report, Oil Exploration Co., Baghdad, 17 p.
BUSHINSKY, G. I., 1961, Stylolites:Izv. Akad. Nauk. S.S.S.R Series Geol., v. 8, p. 31–46 (English translation).
CHATTON, M., 1961, Announcement of a new rock unit, Kifl Formation. OEC unpublished report, Baghdad, 3 p.
CLARK, D.N. and SHEARMAN, D.J., 1980, Replacement anhydrite in limestone and the recognition of moulds and pseudomorphs: a review:Revista del Instituto de Investigaciones Geologicas, v. 34, p. 161–186.
DUNNINGTON, H.V., 1959. Mesozoic and Paleozoic,in van Bellen, R.C., Dunnington, H.V., Wetzel, R. and Morton, D.M., (eds.), Iraq: F10a Lexique Stratigraphique International, 3, Asia: Paris. Centre National de la Recherche Scientifique, International Geologic Congress, Commission de Stratigraphie, 333 p.
DUNNINGTON, H.V., 1968, Salt tectonic features of northern Iraq,in Mattox, R.B., (ed.), Saline deposits. Geological Society of America, Special Paper, 88, 183–220.
EL-SAYED, M.I., FAIRCHILD, I.J. and SPIRO, B., 1991, Kuwaiti dolocrete petrology, geochemistry and groundwater origin:Sedimentary Geology, v. 73, p. 59–75.
FOLK, R.L. and PITTMAN, J.S., 1971, Length-slow chalcedony: a new testament for vanished evaporites:Journal of Sedimentary Petrology, v. 41, p. 1045–1058.
HOVORKA, Susan, 1992, Halite pseudomorphs after gypsum in bedded anhydrite-clue to gypsum-anhydrite relationships:Journal of Sedimentary Petrology, v. 62, p. 1098–1111.
HOVORKA, SUSAN, and Granger, Patricia, 1988, Subsurface to surface correlation of Permian evaporites San Andres-Blaine Flowerpot — relationships, Texas Panhandle. Midcontinent SEPM special paper No.1, p. 137–159.
IBRAHIM, G.M.S., 1978, Sabkha sediments of the Lower Fars Formation, North Iraq. Unpublished M.Sc. thesis, Department of Geology, University of Bristol, U.K., 174 p.
ION, D.C., ELDER, S., and PEDDER, A.E., 1951, The Agha Jari oilfield. Proc. Third World Petroleum Congress, section 1, p. 162–186.
KENT, K.E., 1958, Recent studies of south Persian salt plugs:American Association of Petroleum Geologists Bulletin, v. 42, p. 2951–2972.
O’BRIEN, C.A.E., 1950, Tectonic problems of oilfield belts of southwest Iran. International Geological Congress, v. 6, p. 4558.
OWEN, R.M.S. and NASR, S.N., 1958. The stratigraphy of the Kuwait-Basrah area,in Lewis, L.G., (ed.), Habitat of oil, symposium,American Association of Petroleum Geologists Bulletin, p. 1252–1278.
SADOONI, F. and MOHAMMAD, K., 1987, Recent gypcrete sediments near Tharthar Depression, upper central Iraq. Conference on Quaternary Sediments in Arabian Gulf and Mesopotamian region, Kuwait, (Abs.).
SADOONI, F. and SAEED, S., 1987, Upper Triassic carbonate evaporite sediments of NW Iraq. 8th International Association of Sedimentologists Regional Meeting, Tunisia, (Abs.).
SHAWKAT, M.G. and TUCKER, M.E., 1978, Stromatolites and sabkha cycles from the Lower Fars Formation (Miocene) of Iraq,Geol. Rundschau, v. 67, p. 1–14.
SCHOLLE, Peter A., ULMER, Dana S. and MELIM, Leslie A., 1992, Late-stage calcite in the Permian Capitan Formation and its equivalents, Delaware Basin margin, west Texas and New Mexico: evidence for replacement of precursor evaporites,Sedimentology, v. 39, p. 207–234.
SHEARMAN, D.J., 1963. Recent anhydrite, gypsum, dolomite and halite from the coastal flats of the Arabian shore of the Persian Gulf. Proceedings of the Geological Society, London, p. 63–65.
SHEARMAN, D.J., 1966, Origin of marine evaporite by diagenesis.Transaction of the Institute of Mining and Metallurgy (B), v. 75, p. 208–215.
STOCKLIN, J., 1968, Structural history and tectonics of Iran: a review,American Association of Petroleum Geologists Bulletin, v. 52, p. 1229–1258.
WETZEL, R., 1959, Kurra Chine Formation,in R.C. van Bellen, Dunnington, H. V. and Wetzel, R. and Morton, D.M., (eds.), Lexique Stratigraphique International, v. 3, Asie, 10a, Iraq: Editor: L. Dubertret. Centre National de le Recherche Scientifique, p. 160–162.
WOOD, G.V. and WOLF, M.J., 1969, Sabkha cycle in the Arab/Darb Formation of the Trucial Coast of Arabia.Sedimentology, v. 12, p. 166–191.
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Sadooni, F.N. Diagenetic features of some subsurface Tertiary-Cretaceous evaporites from northern Iraq. Carbonates Evaporites 10, 45–53 (1995). https://doi.org/10.1007/BF03175239
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DOI: https://doi.org/10.1007/BF03175239