ABSTRACT Well logs and biostratigraphic data from six wells in the “XB Field”, central Swamp Depobelt, Niger Delta were integrated to carry out a sequence stratigraphic analysis of depositional systems in the field. The analysis revealed four 3rd order depositional sequences (SEQ1 to 4) bounded by three erosional unconformities interpreted as Sequence Boundaries (SB1 to 3). Transgressive Surfaces of Erosion (TSE1 to 3) that mark the onset of marine flooding and turnarounds from progradational facies to retrogradational facies during sequence build-up were delineated. Three 3rd order Maximum Flooding Surfaces (MFS1, MFS2 and MFS3) characterized by marker shales, high faunal abundance and diversity were also delineated and dated 15.9, 17.4 and 19.4 Ma, respectively. The delineated sequences comprised Lowstand Systems Tracts (progradational packages), Transgressive Systems Tracts (retrogradational packages) and Highstand Systems Tracts (aggradational packages), which reflect depositional systems deposited during different phases of base level changes. The Lowstand Systems Tract (LST) consists of Basin Floor Fans (BFF), Slope Fans and Channel Sands deposited when sea level was low and accommodation space lower than rate of sediment influx. Transgressive Systems Tract (TST) consists of retrogradational marine shales deposited during high relative sea levels and when accommodation space was higher than rate of sediment influx. Highstand Systems Tracts (HST) consisted of shoreface sands displaying mostly aggradational to progradational stacking patterns. The sands of LST and HST show good reservoir qualities while the shales of the TSTs could form potential reservoir seals. The above recognized sequences, were deposited within the Neritic to Bathyal paleoenvironments and are dated mid-Miocene (15.9 - 20.4 Ma) in age.
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S. Onyekuru, E. Ibelegbu, J. Iwuagwu, A. Essien and C. Akaolisa, "Sequence Stratigraphic Analysis of “XB Field”, Central Swamp Depobelt, Niger Delta Basin, Southern Nigeria," International Journal of Geosciences, Vol. 3 No. 1, 2012, pp. 237-257. doi: 10.4236/ijg.2012.31027.
 H. Posamentier, M. Jervey and P. Vail, “Eustatic Controls on Clastic Deposition in Conceptual Framework,” In: C. Wilgus, B. S. Hastings, C. G. Kendall, H. W. Posamentier, C. A. Ross and J. C. Van Wagoner, Eds., Sea level Changes: An Integrated Approach, Vol. 42, SEPM Special Publication, 1988, pp. 109-124.
 B. D. Evamy, J. Haremboure, P. Kamerling, W. A. Knaap, F. A. Molloy and P. H. Rowlands, “Hydrocarbon Habitat of Tertiary Niger Delta,” American Association of Pe-troleum Geologists Bulletin, Vol. 62, No. 1, 1978, pp. 1-39.
 K. C. Short and A. J. Stauble, “Outline of Geology of Niger Delta,” American Association of Petroleum Geologists Bulletin, Vol. 51, No. 5, 1967, pp. 761-779.
 A. J. White-man, “Nigeria, Its Petroleum, Geology, Resources and Poten-tial,” Graham and Trotman, London, 1982.
 H. Doust and E. Omatsola, “Niger Delta,” In: J. D. Edwards and P. A. San-togrossi, Eds., Divergent/Passive Margin Basins, American Association of Petroleum Geologists Memoir, Vol. 48, 1990, pp. 201-238.
 H. Kulke, “Nigeria,” In: H. Kulke, Ed., Re-gional Petroleum Geology of the World, Part II: Africa, Amer-ica, Australia and Antarctica, Gebrüder Borntraeger, Berlin, 1995, pp. 143-172.
 J. Hospers, “Gravity Field and Struc-ture of the Niger Delta, Nigeria, West Africa,” Geological So-ciety of Ame- rican Bulletin, Vol. 76, No. 4, 1965, pp. 407-422.
 A. Kaplan, C. U. Lusser and I. O. Norton, “Tectonic Map of the World, Panel 10, Tulsa,” American Association of Petroleum Geologists, Scale 1:10000000, 1994.
 M. L. W. Tuttle, R. R. Charpentier and M. E. Brownfield, “The Niger Delta Petro-leum System: Niger Delta Province, Nigeria, Cameroon, and Equatorial Guinea, Africa,” USGS Open-File Report 99-50-H, 1999.
 C. G. Kendall and L. Pomar, “Systems Tract, Bounding Surfaces, Lithofacies, Geometric Hierarchies and Stacking Patterns: Keys to Shallow Water Carbonate Interpre-tation,” American Association of Petroleum Geologistst Bulle-tin, Vol. 89, 2005.
 S. H. Williams, “Graptolites, Acri-tarchs and Scolecodonts at Green Point, Western Newfound-land,” International Cambrian-Ordovician Boundary Working Group, Circular, 1997, pp. 6-15.
 P. R. Vail, R. M. Mitchum and S. Thompson, “Seismic Stratigraphy and Global Changes of Sea Level, Part 3: Relative Changes of Sea Level from Coastal Onlap,” In: C. E. Payton, Ed., Seismic Stratigra-phy-Applications to Hydrocarbon Exploration, AAPG Memoir, Vol. 26, 1977, pp. 63-81.
 J. C. Van Wagoner, H. W. Posamentier, R. M. Mitchum, P. R. Vail, J. F. Sarg, T. S. Loutit and J. Hardenbol, “An Overview of the Fundamentals of Se-quence Stratigraphy and Key Definitions,” In: C. Wilgus, B. S. Hastings, C. G. Kendall, H. W. Posamentier, C. A. Ross and J. C. Van Wagoner, Eds., Sea Level Changes: An Integrated Ap-proach, Vol. 42, SEPM Special Publication, 1988, pp. 39- 46.
 B. U. Haq, J. Hardenbol, P. R. Vail, “Mesozoic and Cenozoic Chronostratigraphy and Cycles of Sea-Level Change,” In: C. Wilgus, B. S. Hastings, C. G. Kendall, H. W. Posamentier, C. A. Ross and J. C. Van Wagoner, Eds., Sea Level Changes: An Integrated Approach, Vol. 42, SEPM Spe-cial Publication, 1988, pp. 72-108.
 O. S. Adegoke, M. E. Omatsola and M. B. Salami, “Benthic Foraminifera Biofacies, off the Niger Delta,” Maritime Sediments Special Publication, Vol. 1, 1976, pp. 279-292.
 H. M. Bolli and J. B. Saunders, “Oligocene to Holocene Low Latitude Planktic Foraminifera,” In: H. M. Bolli, J. B. Saunders and K. Perch-Nielsen, Eds., Plankton Stratigraphy, Cambridge University Press, Cambridge, 1985, pp. 155-257.
 K. Perch-Nielsen, “Cenozoic Cal-careous Nannofossils,” In: H. Bolli, J. Saunders and K. Perch-Nielsen, Eds., Plankton Stratigraphy, Cambridge Univer-sity Press, Cambridge, 1985, pp. 427-545.
 F. T. Beka and M. N. Oti, “The Distal Offshore Niger Delta: Frontier Prospects of a Mature Petroleum Province,” In: M. N. Oti and G. Postma, Eds., Geology of Deltas, A. A. Balkema, Rotterdam, 1995, pp. 237-241.
 A. M. McCABE, G. F. Dardis and P. M. Hanvey, “Glacial Sedimentology in Northern and Western Ireland, In: Pre- and Post-Symposium Field Excursion Guide Book, Anglia Polytechnic, Cambridge, 1992.
 G. P. Allen and H. W. Posamentier, “Sequence Stratigraphy and Facies Model of an Incised Valley Fill: The Gironde Estuary, France,” Journal of Sedimentary Petrology, Vol. 63, No. 3, 1993, pp. 378-391.
 D. Emery and K. Myers, “Sequence Stratigra-phy,” Blackwell Science Ltd., Oxford, 1996.
 S. Boggs, “Principles of Sedimentology and Stratigraphy,” 2nd Edition, Prentice Hall, Englewood Cliffs, 1995.
 R. G. Walker and A. G. Plint, “Wave- and Storm-Dominated Shallow Marine Systems,” In: R. G. Walker and N. P. James, Eds., Facies Mod-els-Response to Sea-Level Changes, Geological Association of Canada, Newfoundland, 1992, pp. 219-238.
 H. Posamen-tier and P. R. Vail, “Eustatic Controls on Clastic Deposition II—Sequence and Systems Tract Models,” In: C. Wilgus, B. S. Hastings, C. G. Kendall, H. W. Posamentier, C. A. Ross and J. C. Van Wagoner, Eds., Sea Level Changes: An Integrated Ap-proach, Vol. 42, SEPM Special Publication, 1988, pp. 125-154.
 M. Shaffer, “Minimum Viable Populations: Coping with Uncertainty,” In: M. E. Soule, Ed., Viable Popula-tions for Conservation, Cambridge University Press, Cam-bridge, 1987, pp. 69-86. doi:10.1017/CBO9780511623400.006
 C. D. Winker, “Cenozoic Shelf Margins, Northwestern Gulf of Mexico,” Gulf Coast Association of Geological Societies, Vol. 32, 1982, pp. 427-448.
 P. Stacher, “Present Understanding of the Niger Delta Hydrocarbon Habitat,” In: M. N. Oti and G. Postma, Eds., Geology of Deltas, A. A. Balkema, Rotterdam, 1995, pp. 257-267.
 W. Galloway, “Genetic Stratigraphic Sequences in Basin Analysis I: Architecture and Genesis of Flooding Sur-face Bounded Depositional Units,” American Association of Petroleum Geologists Bulletin, Vol. 73, No. 2, 1989, pp. 125-142.