Abstract
The study is based on subsurface sequences of bioclastic limestone in Kirkuk area, Northeastern Iraq. These sequences were deposited in a shallow, open marine environment during late Oligocene. Tests of larger foraminifera Lepidocyclina (Nephrolepidina) are abundant in the lower and upper parts of the Baba Formation. Biometric investigations of the oriented tests megalospheric of Nephrolepidina assemblages from, Bai-Hassan well-25 section, identified three morphometrically species (Lepidocyclina praemarginata, Lepidocyclina ex.interc praemarginata-morgani, and Lepidocyclina morgani). The identification is based on the combination of three parameters, the first is factor A which consist of degree of embracement of protoconch by the deuteroconch. The second one (factor B) includes the number of accessory auxiliary chambers on the deuteroconch. The last one (factor C) is the expression of the angle (Alfa) which is formed by the two hypothetical line from the center of protoconch through the outer attachment points of the deuteroconch walls protoconch.
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References
Abid AA (1997) Biostratigraphy and microfacies of the late oligocene-M formations center and north Iraq. (Unpublished) Ph.D. Thesis, Coll. of Baghdad Univ., p 258. (In Arabic)
Adams CG (1987) On the classification of the Lepidocyclinidae (foraminifera) wire-description of the unrelated Paleocene genera Actinosiphon and Orbitosiphon. Micropaleontology 33(4):289–317, pls. 1-4
Al-Gburi HMQ, El-Esia RM (2002) The stratigraphy and depositional environment of Paleogene –Lower Neogene subsurface sequence in the area between Bai-Hassan and Al-Qayarah oil fields. 5th Iraqi Geological Congress, Baghdad
Al-Hashimi HAJ, Amer RM (1985) Tertiary microfacies of Iraq. D.G. geol. Surv. Min. Invest. Puli., Baghdad, 56pp, 17figs., 159pls. (S.O.M.)
Bellen RC Van (1956) The stratigraphy of the main limestone of Kirkuk, Bai-Hassan and qarah Chaugh Dagh strucures in Northern Iraq. Inst. Petroleum found. 42. London
Berning B, Reuter M, Piller WE, Harzhauser M, Kroh A (2009) Larger foraminifera as a substratum for encrusting bryozoans (Late Oligocene, Tethyan Seaway, Iran). Facies. doi:10.1007/s10347-008-0169-x
Cole WS (1938) Stratigraphy and micropaleontology of two deep wells in Florida. Florida Geol Surv Bull 16:1–73
De Mulder EFJ (1975) Microphona and sedimentary tectonic history of the Oligo-Miocene of the Joniane Islamnd and Western Europe (Greece). Ulrecht Micropal Bull 13:140
Douvillé H (1898) Sur I’age des couches traverse/es par le canal du Panama. Soc Ge/ol France Bull 3(26):587–600
Drooger CW (1993) Radial foraminifera morphometrics and evolution, verhamd, Kon. Ned. Akad. Wetensch. Amesterdam, pp. 1–241
Drooger CW, Freudenthal T (1964) Associations of Miogypsina and Lepidocyclina at some European localities. Eclogae Geol Helv 57:509–528
Drooger CW, Laagland HM (1986) Larger foraminiferal zonation of the Europian-Mediteeriane Oligocene. Proc Kon Ned Akad Wet ser B 189:135–148
Drooger CW, Rohling Ej (1988) Lepidocylina migration across the Atlantic, Journal of Paleontology, Procceedings loninklijike Nederlandse Academie wetenschappen, (B), 91:39–52
El-Eisa MES (1992) Coral reef of late oligocene-early miocene, Kirkuk and surrounding area. Iraqi Geol J 25(2):17–32, In Arabic
Freudenthal Th (1966) Nephrolepidina at some classical European localities. Proc. 3rd Sess. Comm. Med. Neog. Strat., Berne 1964:pp.55–57. Brill, Leiden
Geerates W (1983) Biometrical analysis of early middle Oligocene Nephrolepidina praemarginata and Heterostegina sp. Associations from Villajoyosa, SE.Spain Inter Rep. Dept. Stratigraphy State Univ. Utrecht. 91 pages
Ghafor IM (2004) Biometric analysis of Lepidocylina(Nephrolepidina)and Miogypsinids from Baba and Azkand formations (Oligocene-Miocene) In Kirkuk area, Iraq.Ph. D. Thesis. University of Sulaimani. Iraq. 70 Figs., 16 plates. 159 pages
Ghafor IM (2011) Microfacies and biostratigraphy of Baba formation (Late Oligocene) in Bai Hassan Oil-Well-25, Kirkuk area, Central, North Iraq. Iraqi Bulletin of Geology and Mining 7(3):25–32
Hadad NH (1991) Biostratigrapgic studies for the tertiary formations in some oilfields, in the area of N.O.C. Kirkuk Office, unpublished (In Arabic)
Mohammed QA (1983) Biostratigraphy of Kirkuk Group in Kirkuk and Bai-Hassan areas, Unpublish. M.Sc. Thesis, coll. Sci. Univ. of Baghdad
Mulenkamp JE, Amato V (1972) Cycloclypeus and Nephrolepidina from th Oligocene of mollero (N. Italy). Id., (B) 75:34–47
Muthukrishnan S, Saraswati PK (2001) Shape analysis of the nucleoconch of Lepidocyclina from Kutch-ataxonomic interpretation. Micropaleontology 47(1):87–92, text figures, 1-33, plates 1
O¨zcan E, Less G, Beke MB, Kollanyi K, Acar F (2009) Oligo-miocene foraminiferal record, (Miogypsinidae,Lepidocyclinidae and Nummulitidae) from the Western Taurides(SW Turkey): biometry and implications for the regional geology. J Asian Earth Sci 34:740–760
Saraswati PK (1995) Biometry of early oligocene Lepidocyclina from Kutch, India. Mar Micropaleontol 20:303–311
Saraswati PK, Kumar A (2000) Morphometrics of some Lepidocyclina foraminifera: applications in taxonomy and biostratigraphy. Geological data analysis: statistical methods. Hindistan Publishing Corporation, New Delhi, pp 63–70, Figs. 6
Hok TS (1936) Beitrag zur Kenntnnis der Lepidocycliniden. Proc Kon Akad Wet Amsterdam 39:990–999
Van Der Vlerk, IM (1929) Groote Foraminiferen van Noord-Oost borneo. Id., 9: p. 5–44
Van Der Vlerk IM (1957) Des Stratigrafische betekensis van het “genu Lepidocyclina”. Proc Kon Ned Akad Wet (B) 66:23–27
Van Der Vlerk IM (1959a) Modification de I’ontogénése pendant I’évolution des Lépedocyclines (Foraminifers). Bull Soc Geol Fr 1(7):669–673
Van Der Vlerk IM (1959b) Problems and principles of tertiary and quaternary stratigraphy. Q J Geol Soc Lond 115:49–63
Van Der Vlerk IM (1963a) Lepidocyclina radiata (K. Martin), 1880. Proc K Ned Akad Wet B 74:620–626
Van Der Vlerk IM (1963b) Biometrical research on Lepidocyclina. Micropaleontology 9:425–426
Van Der Vlerk IM (1974) Nomenclatural and numerical taxonomy (names and numbers). Verh Naturforsch Ges Basel 84:245–255
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Ghafor, I.M. Evolutionary aspects of Lepidocyclina (Nephrolepidina) from Baba Formation (late Oligocene) in Bai-Hassan well-25, Kirkuk area, Northeast Iraq. Arab J Geosci 8, 9423–9431 (2015). https://doi.org/10.1007/s12517-015-1865-9
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DOI: https://doi.org/10.1007/s12517-015-1865-9