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Magnetostratigraphy and rock magnetism of the Boom Clay (Rupelian stratotype) in Belgium

  • D. Lagrou (a1), N. Vandenberghe (a1), S. Van Simaeys (a1) and J. Van Hus (a2)

This paper presents the results of a detailed rock magnetic and magnetostratigraphic study of the Lower Oligocene Rupelian unit-stratotype. Notwithstanding the relatively low intensity of the natural remanent magnetisation and the diverse and often unstable behaviour during demagnetisation, close-spaced sampling and accurate polarity determinations allowed us to determine the magnetic polarity zonation. The recognition of the characteristic magnetic polarity and the correlation with the standard magnetobiochronologic time scale yields an accurate chronostratigraphic dating of the Boom Clay Formation. The boundary between the geomagnetic chrons C12n and C12r nearly coincides with the lithostratigraphic boundary between the Terhagen and Putte Members. Rock magnetic techniques point to magnetite and probably also iron sulphides as the main magnetic remanence carriers. These magnetic minerals could, however, not be identified with classical mineralogical techniques performed on magnetic extractions. The failure to detect them may be due to the low concentration of these minerals, the small grain size, and the close physical relation with pyrite.

Corresponding author
* Flemish Institute for Technological Research (Vito), Boeretang 200, B-2400 Mol, Belgium. E-mail:
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Ali J.R., King C. & Hailwood E.A., 1993. Magnetostratigraphic calibration of early Eocene depositional sequences in the southern North sea basin. In: Hailwood E.A. & Kidd R.B. (eds) : High Resolution Stratigraphy, Geological Society London Special Publication 70 (London): 99125.
Berggren W.A., Kent D.V., Swisher C.C. III & Aubry M.-P., 1995. A revised Cenozoic Geochronology and Chronostratigraphy. In: Berggren W.A., Kent D.V., Aubry M-R. & Hardenbol J. (eds): Geochronology, Time Scales and Global Stratigraphic Correlation, Society for Sedimentary Geology (SEPM), Special Publication 54: 129212.
Berner R.A., 1984. Sedimentary pyrite formation: An update. Geochimica et Cosmochimica Acta 48: 605615.
Blow W.H., 1979. The Cainozoic Globigerinida (3 volumes). Brill: 1412 pp.
Cande S.C. & Kent D.V., 1992. A new geomagnetic polarity time scale of the Late Cretaceous and Cenozoic. Journal of Geophysical Research 97: 1391713951.
De Craen M., Swennen R. & Keppens E., 1999. Petrography and geochemistry of septarian carbonate concretions from the Boom Clay Formation (Oligocene, Belgium). Geologie en Mijnbouw 77: 6376.
Dekkers M.J., 1989. Magnetic properties of natural pyrrhotite part II: High- and low-temperature behaviour of Jrs and TRM as function of grain size. Physics of the Earth and Planetary Interiors 57: 266283.
Dekkers M.J., 1997. Environmental magnetism: an introduction. Geologie en Mijnbouw 76: 163182.
Florindo F. & Sagnotti L., 1995. Palaeomagnetism and rock magnetism in the upper Pliocene Valle Ricca (Rome, Italy). Geophysical Journal International 123: 340354.
Hailwood E.A. & Ting E., 1990. Preliminary magnetostratigraphic investigations of the Oligocene Boom Clay (Belgium) and Bovey Beds (UK). Tertiary Research 11: 209.
Haq B.U, Hardenbol J. & Vail P.R., 1987. Chronology of fluctuating sea level since the Triassic. Science 235: 11561167.
Hardenbol J., Thierry J., Farley M.B., Jacquin T., de Graciansky P.C. & Vail P., 1998. Mesozoic and Cenozoic sequence chronostratigraphic framework of European Basins. In: Graciansky P.C., Hardenbol J., Jacquin T. & Vail P.R. (eds): Mesozoic and Cenozoic Sequence Stratigraphy of European Basins, Society for Sedimentary Geology (SEPM), Special Publication 60: 313.
Hartl P., Tauxe L. & Constable C., 1993. Early Oligocene geomagnetic field behaviour from deep sea drilling Project site 522. Journal of Geophysical Research 98: 1964919665.
Hooyberghs H., 1983. Contributions to the study of planktonic Foraminifera in the Belgian Tertiary. Aardkundige Mededelingen (Leuven University Press) 2: 131 pp.
Hooyberghs H.J.F., 1992. Planktonic foraminiferal biostratigraphy in the Boom Formation at Kruibeke and Antwerp (Northern Belgium). In: Hooyberghs H., Vercauteren T., De Meuter F. & Symons F. (eds): Foraminiferal studies in the Boom Formation. Professional Paper, Belgian Geological Survey (Brussels) 258: 110.
Laenen B. & De Craen M., 2004. Eogenetic siderite as an indicator for fluctuations in sedimentation rate in the Oligocene Boom Clay Formation (Belgium). Sedimentary Geology 163: 165174.
Lagrou D., 1992. Magnetostratigrafie van de Boomse Klei in het stratotype gebied. Master thesis, KU Leuven, Leuven: 92 pp. (in Dutch).
Lowrie W., 1990. Identification of ferromagnetic minerals in a rock by coercivity and unblocking temperature properties. Geophysical Research Letters 17: 159162.
Lowrie W. & Lanci L., 1994. Magnetostratigraphy of Eocene-Oligocene boundary sections in Italy: No evidence for short subchrons within chrons C12R and C13R. Earth and Planetary Science Letters 126: 247258.
Martini E., 1971. Standard Tertiary and Quaternary calcareous nannoplankton zonation. Proceedings of the second planktonic Conference in Roma 1970. Edizioni Tecnoscienza, Roma, 2: 739785.
Mary C, Iaccarino S., Courtillot, V, Besse J. & Aissaoui D.M., 1993. Magnetostratigraphy of Pliocene sediments from the Stirone river (Po Valley). Geophysical Journal International 112: 359380.
Mullender T.A.T., Van Velzen A.J. & Dekkers M.J., 1993. Continuous drift correction and separate identification of ferrimagnetic and paramagnetic contributions in thermo-magnetic runs. Geophysical Journal International 114: 663672.
Poore R.Z., Tauxe L., Percival S.F. Jr. & LaBrecque J.L., 1982. Late Eocene-Oligocene magnetostratigraphy and biostratigraphy at South Atlantic DSDP site 522. Geology 10: 508511.
Prince R.A., Heath G.R. & Kominz M., 1980. Paleomagnetic studies of Central North Pacific sediment cores: Stratigraphy, sedimentation rates, and the origin of magnetic instability. Geological Society of America Bulletin 91: 17891835.
Reynolds R.L., Tuttle M.L., Rice C.A., Fishman N.S., Karachewski J.A. & Sherman D.M., 1994. Magnetization and geochemistry of greigite-bearing Cretaceous strata, North Slope Basin, Alaska. American Journal of Science 294: 485528.
Roberts A.P., 1995. Magnetic properties of sedimentary greigite (Fe3S4). Earth and Planetary Science Letters 134: 227236.
Roberts A.P. &Turner G.M., 1993. Diagenetic formation of ferrimagnetic iron sulphide minerals in rapidly deposited marine sediments, South Island, New Zealand. Earth and Planetary Science Letters 115: 57273.
Snowball I.F., 1994. Bacterial magnetite and the magnetic properties of sediments in a Swedish lake. Earth Planetary Science Letters 126: 129142.
Snowball I.F. & Thompson R., 1990. A stable chemical remanence in Holocene sediments. Journal of Geophysical Research 95: 44714479.
Steurbaut E., 1986. Late Middle Eocene to Middle Oligocene Calcareous nannoplankton from the Kallo well, some boreholes and exposures in Belgium and a description of the Ruisbroek Sand Member. Mededelingen Werkgroep Tertiair en Kwartair Geologie 23(2): 4983.
Steurbaut E., 1992. Integrated stratigraphic analysis of Lower Rupelian Deposits (Oligocene) in the Belgian basin. Annales de la Société Géologique de Belgique 115: 287306.
Stover L.E. & Hardenbol J., 1994. Dinoflagellates and depositional sequences in the Lower Oligocene (Rupelian) Boom Clay Formation, Belgium. Bulletin van de Belgische Vereniging voor Geologie 102 (12): 577.
Thompson R. & Cameron T.D.J., 1995. Paleomagnetic study of Cenozoic sediments in North Sea boreholes: an example of a magnetostratigraphic conundrum in a hydrocarbon producing area. In: Turner P. & Turner A. (eds): Palaeomagnetic Applications in Hydrocarbon Exploration and Production. Geological Society London, Special Publication 98: 223236.
Vandenberghe N., 1978. Sedimentology of the Boom Clay (Rupelian) in Belgium. Verhandelingen Koninklijke Academie Wetenschappen Letteren en Schone Kunsten van België, Klasse Wetenschappen (Brussel) 147: 137 pp.
Vandenberghe N. & Laga P., 1986. The septaria of the Boom Clay (Rupelian) in its type area in Belgium. Aardkundige Mededelingen (Leuven University Press) 3: 229238.
Vandenberghe N. & Van Echelpoel E., 1987. Field guide to the Rupelian stratotype. Bulletin van de Belgische Vereniging voor Geologie 96: 325337.
Vandenberghe N., Laenen B., Van Echelpoel E. & Lagrou D., 1997. Cyclostratigraphy and climatic eustasy. Example of the Rupelian stratotype. Comptes Rendus de l’Académie des Sciences (Paris), Sciences de la Terre et des Planètes 325: 305315.
Vandenberghe N., Laga P., Steurbaut E., Hardenbol J. & Vail P., 1998. Tertiary Sequence Stratigraphy at the Southern Border of the North Sea Basin in Belgium. In: de Graciansky P.C., Hardenbol J., Jaquin T. & Vail P.R. (eds): Mesozoic and Cenozoic Sequence Stratigraphy of European Basins. Society for Sedimentary Geology (SEPM), Special Publication 60: 119154.
Van Hoof A.A.M. & Langereis C.G., 1991. Reversal records in marine marls and delayed acquisition of remanent magnetization. Nature 351: 223225.
Van Simaeys S., De Man E., Vandenberghe N., Brinkhuis H., Steurbaut E., 2004. Stratigraphic and palaeoenvironmental analysis of the Rupelian-Chattian transition in the type region: evidence from dinoflagellate cysts, foraminifera and calcareous nannofossils. Palaeogeography, Palaeoclimatology, Palaeoecology 208:3158.
Van Velzen A.J., Dekkers M.J. & Zijderveld J.D.A., 1993. Magnetic iron-nickel sulphides in the Pliocene and Pleistocene marine marls from the Vrica section (Calabria, Italy). Earth and Planetary Science Letters 115: 4355.
Wei W. & Wise S.W., 1989. Discoaster praebifax n.sp. – A possible ancestor of Discoaster bifax Bukry (Coccolithophoridae). Journal of Paleontology 63: 1014.
Williams G.L., Brinkhuis H., Pearce M.A., Fensome R.A., Weegink J.W., 2004. Southern Ocean and global dinoflagellate cyst events compared; Index events for the Late Cretaceous-Neogene. In: Exon N.F., Kennett J.P. & Malone M.J. (eds), Proceedings of the Ocean Drilling Program, Scientific Results ODP Leg 189: 198 [Online]. Available from World Wide Web: <>.
Zijderveld J.D.A., Hilgen F.J., Langereis C.G., Verhallen P.J.J.M. & Zachariasse W.J., 1991. Integrated magnetostratigraphy and biostratigraphy of the upper Pliocene-lower Pleistocene from the Monte Singa and Crotone areas in Calabria, Italy. Earth and Planetary Science Letters 107: 697714.
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