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The distribution of Pre-Westphalian source rocks in the North German Basin – Evidence from magnetotelluric and geochemical data

Published online by Cambridge University Press:  01 April 2016

N. Hoffmann
Affiliation:
Bundesanstalt für Geowissenschaften und Rohstoffe, Dienstbereich Berlin, Wilhelmstr. 25–30, D-13593 Berlin, Germany
H. Jödicke
Affiliation:
Institut für Geophysik der Westfälischen Wilhelms-Universität Münster, Corrensstr. 24, D-48149 Münster, Germany
P. Gerling*
Affiliation:
Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover, Germany
*
1Corresponding author; e-mail: peter.gerling@bgr.de

Abstract

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For the first time this project attempts to directly correlate magnetotelluric and geochemical data with the aim of creating a model on the regional distribution of potential pre-Westphalian source rocks deposited in marine environments in the North German basin.

Analysis of the magnetotelluric data shows, that there is a deep good conductor at the north-eastern fringe of the North German basin around the islands of Rügen and Usedom and on the mainland north east of the Anklam Fault. Through integration with seismic data and the offshore well G14 the conductor can be correlated with the Cambro-Ordovician Scandinavian Alum shales. To the south an adjoining area approximately corresponding to the depo-centre of the Rotliegend basin lacks a deep good conductor. Therefore it can be assumed that a regional distribution of comparable source rocks is unlikely. Another excellent and important conductor starts to the south west of the Lower Elbe Line extending along the Dutch-German border into the North Sea, and into the Münsterland. Its place in the local stratigraphy has not been adequately established. It is most likely that this good conductor corresponds to the black shales of the Early Namurian and the Dinantian, which is the case in the boreholes Münsterland 1 and Pröttlin 1 for example. In this paper they are collectively called Rhenohercynian Alum shales. On the Dutch-German border a transition into the “Bowland Shale” facies or equivalents is to be expected. It cannot be ruled out that even stratigraphically older black shales, possibly from the Cambro-Ordovician could contribute to the high integrated conductivity of the deep good conductor.

The evidence of highly conductive layers in the deep subsurface poses the question whether these layers could be potential source rocks for the gases in the north German gas fields. This question can be answered with a clear yes. Gas and isotope geochemical studies on gases from producing Rotliegend deposits have shown that Rhenohercynian Alum shales have been a significant source for these fields. This will be illustrated in detail using the gas fields from the production province “Ems Estuary” as an example.

Type
Conference papers
Copyright
Copyright © Stichting Netherlands Journal of Geosciences 2001

References

Andersson, A., Dahlman, B., Gee, D.G., & Snail, S., 1985. The Scandinavian Alum shales. Sveriges Geologiska Undersökning, Ser. Ca Nr. 56; Uppsala.Google Scholar
Arner, U. & Faber, E., 1996. Empirical carbon isotope/maturity relationships for gases from algal kerogens and terrigenous organic matter, based on dry, open-system pyrolysis. Organic Geochemistry 24: 947955 Google Scholar
Buchardt, B. & Lewin, M.D., 1990. Reflectance of vitrinite-like maceráis as a thermal maturity index for Cambro-Ordovician Alum shales, southern Scandinavia. Am. Ass. Petrol. Geol. Bull. 74, 4: 394406;Tulsa.Google Scholar
Cameron, T.D.J., 1993. Carboniferous and Devonian (southern North Sea). In: Knox, & Cordey, (eds.): Lithostratigraphic nomenclature of the UK North Sea 5: 193; Nottingham; BGS & UKOOA.Google Scholar
Dohr, G., 1989. Ergebnisse geophysikalischer Arbeiten zur Untersuchung des tieferen Untergrundes in Norddeutschland. Nds. Akad. Geowiss. Veröfftl. 2: 447; Hannover.Google Scholar
Duba, A., Huenges, E., Nover, G., Will, G. & Jödicke, H., 1988. Impedance of black shale from Münsterland 1 borehole: an anomalously good conductor? Geophys. J. 94: 413419.Google Scholar
Everlien, G., 1997. Hydrous pyrolysis of high-maturity Paleozoic coals and black shales from Central Europe and adjacent areas -Thermodynamic Considerations. Geol. Jb. D 103: 4364; Hannover.Google Scholar
Everlien, G. & Wehner, H., 1994. Organisch-geochemische und nass-pyrolytische Untersuchungen an prä-westfalen Muttergesteinen aus Zentral- und Westeuropa. BGR-internal report 112.393: 1–57, 28 Abb., 21 Tab.; Hannover.Google Scholar
Franke, D., Gründel, J., Lindert, W., Meissner, B., Schulz, E., Zagora, I. & Zagora, K., 1994. Die Ostseebohrung G14 - Eine Profilübersicht. Z. Geol. Wiss. 22(1-2): 235240; Berlin.Google Scholar
Gerling, P., Idiz, E., Everlien, G. & Sohns, E., 1997. New aspects on the origin of nitrogen in natural gas in northern Germany. Geologisches Jahrbuch, Reihe D, 103: 6584; Hannover.Google Scholar
Gerling, P., Lokhorst, A., Nicholson, R.A. & Kotarba, M., 1998. Natural gas from pre-Westphalian sources in Northwest Europe - A new exploration target? 1998 International Gas Research Conference, 8–11 November 1998, San Diego, California USA; Proceedings (CD ROM): 219229.Google Scholar
Gerling, P., Kockel, F. & Krull, P., 1999. Das Kohlenwasserstoff-Potential des Präwestfals im Norddeutschen Becken - Eine Synthese. DGMK-Forschungsbericht 433: XII + 107 S., 1 Anhang; Hamburg.Google Scholar
Göthe, W., 1990. Zur elektrischen Leitfähigkeit des tieferen Untergrundes im Norden der DDR. In: Haak, V. & Homilius, J. (Hrsg. Prot. 13. Koli. „Elektromagnetische Tiefenforschung” Hornburg, 19.-23.3.1990: 13–21 ; Frankfurt/Main, Hannover.Google Scholar
Gurk, M., Jording, A. & Jödicke, H., 1996. Magnetotellurik zwischen Nienburg/Weser und Lauenburg/Elbe. In: Bahr, K. und Junge, A. (Hrsg.): Prot. 16. Koli. “Elektromagnetische Tiefenforschung” auf Burg Ludwigstein, 9. - 11.4.1996: 3–14; Potsdam, Frankfurt.Google Scholar
Hoffmann, N., Jödicke, H., Fluche, B., Jording, A. & Müller, W., 1998. Modellvorstellungen zur Verbreitung potentieller präwest-falischer Erdgas-Muttergesteine in Norddeutschland - Ergebnisse neuer magnetotellurischer Messungen - Z. angew. Geol. 44: 140158.Google Scholar
Jödicke, H., 1984. Zur Deutung magnetotellurisch nachgewiesener guter Leiter im tieferen Untergrund Nordwestdeutschlands. In: Haak, V. & Homilius, J. (Hrsg.): Prot. 10. Koli. “Elektromagnetische Tiefenforschung” Grafrath/Oberbayern, 19.-23.3.1984: 331–334; Berlin.Google Scholar
Jödicke, H., 1992. Water and Graphite in the Earth’s Crust- An Approach to Interpretation of Conductivity Models. Surv. Geophys. 13:381407.Google Scholar
Kessel, G., 1994. Potentielle Muttergesteine des Dinant und Namur in Zentral- und NW-Europa. BGR-internal report 111.525: 1–136, 54 Abb., 9 Ani.; Hannover.Google Scholar
Knödel, K., Losecke, W. & Wohlenberg, J., 1979. A Comparison of Results of Geothermal and Magnetotelluric Investigations in Northwestern Germany. J. Geophys. 45: 199207.Google Scholar
Kockel, F. (Hrsg.), 1996. Geotektonischer Atlas von NW-Deutschland (1:300 000). Bundesanstalt für Geowissenschaften und Rohstoffe; Hannover.Google Scholar
Krooss, B., Leythaeuser, D. & Lillack, H., 1993. Nitrogen-rich natural gases - Qualitative and quantitative aspects of natural gas accumulation in reservoirs. Erdöl und Kohle, Erdgas, Petrochemie vereinigt mit Brennstoff-Chemie 46: 271276.Google Scholar
Lokhorst, A., Adlam, K., Brugge, J.V.M., David, R. Diapari, L., Fermom, W.J.J., Geluk, M., Gerling, P., Heckers, J., Kockel, F., Kotarba, M., Laier, T., Lott, G.K., Milaczewski, E., Milaczewski, L. Nicholson, R.A., Platen, F.v. & Pokorski, J., 1998. NW European Gas Atlas - Composition and Isotope Ratios of Natural Gases. CD ROM (ISBN: 90-72869-60-5).Google Scholar
Losecke, W., Knödel, K. & Müller, W., 1979. The conductivity distribution in the North German sedimentary basin derived from widely spaced areal magnetotelluric measurements. Geophys. J. R. astr. Soc. 58: 169179.Google Scholar
Markfort, R., 1998. Die Erprobung eines Impedanz-Phasen-analysators zur Messung elektrischer Gesteinsparameter im Frequenzbereich von 1 mHz bis 32 Mhz. Dipi.-Arb. Inst. f. Geophys. Univ. Münster [unveröff.].Google Scholar
McCartney, J.T. & Ergun, S., 1965. Electron microscopy of graphite crystallites in metaanthracite. Nature 205: 962 – 964.CrossRefGoogle Scholar
Patijn, R.J.H., 1964. Die Entstehung von Erdgas infolge der Nachinkohlung im Nordosten der Niederlande. Erdöl und Kohle; Erdgas, Petrochemie 17: 29.Google Scholar
Porstendorfer, G., 1965. Methodische und apparative Entwicklung magneto-tellurischer Verfahren mit Anwendung auf die Tiefenerkundung im Bereich der norddeutschen Leitfähigkeitsanomalie. Veröff. Inst. f. Geodynamik Jena 3; Deutsche Akad. Wiss., Berlin.Google Scholar
Porstendorfer, G., 1984. Studie zur Durchführung magneto-tellurischer Untersuchungen im Rahmen der Präzechstein-Erkundung der DDR. Forschungsbericht Bergakademie Freiberg, Sektion Geowissenschaften [unveröff.].Google Scholar
Richwien, J., Schuster, A., Teichmüller, R. & Wolburg, J., 1963. Überblick über das Profil der Bohrung Münsterland 1. Fortschr. Geol. Rheinld. u. Westf. 11:9-18; Krefeld.Google Scholar
Schmucker, U., 1959. Erdmagnetische Tiefensondierung in Deutschland 1957–59; Magnetogramme und erste Auswertung. Abh. Akad. Wiss. Göttingen, Math.-Phys. Kl. 5.Google Scholar
Schön, J., 1983. Petrophysik. Physikalische Eigenschaften von Gesteinen und Mineralen. Ferdinand Enke Verlag; Stuttgart.Google Scholar
Stach, E., MacKowsky, M.-Th., Teichmüller, M., Taylor, G.H., Chandra, D., & Teichmüller, R., 1982. Stach’s Textbook of Coal Petrology. 3rd ed.; Gebrüder Borntraeger Verlag; Berlin, Stuttgart.Google Scholar
Stahl, W.J., 1968. Kohlenstoff-Isotopenanalysen zur Klärung der Herkunft norddeutscher Erdgase. PhD Thesis Techn. University Clausthal: 107 pp.Google Scholar
Stahl, W.J. & Jr.Carey, B.D., 1975. Source-rock identification by isotope analyses of natural gases from fields in the Val Verde and the Delaware Basins, West Texas. Chemical Geology 16: 257267.CrossRefGoogle Scholar
Stahl, W.J., Gerling, P., Bandlowa, T., Brückner-Röhling, S., Everlien, G., Hoffmann, N., Kessel, G., Koch, J., Kockel, F., Krull, P., Mittag-Brendel, E., Sohns, E. & Wehner, H., 1996. Deep natural gas, a challenge for the future? In: Kürsten, M. [ed.], World Energy, a Changing Scene, Proc. of the 7th Int. Symp. held in Hannover, Germany, at the Federal Institute for Geosciences and Natural Resources, Oct. 25–27, 1994 169191; E. Schweizerbart’sche Buchhandlung, Stuttgart.Google Scholar
Strobeck, K., 1998. Ein- und zweidimensionale magnetotellurische Modellrechnungen auf Profilen zwischen Fehmarn (Ostsee) und Lippstadt (südliches Münsterland). Dipl.-Arb. Inst. f. Geophys. Univ. Münster [unveröff.].Google Scholar
Teichmüller, M., Teichmüller, R. & Weber, K., 1979. Inkohlung und Ulit-Kristallinität - Vergleichende Untersuchungen im Mesozoikum und Paläozoikum von Westfalen. Fortschr. Geol. Rheinld. u. Westf. 27: 201276; Krefeld.Google Scholar
Tissot, B.P. & Welte, D.H., 1984. Petroleum Formation and Occurrence. Springer-Verlag; Berlin, Heidelberg, New York, Tokyo. Google Scholar
Weidelt, P., 1978. Konstruktion und Erprobung eines Verfahrens zur Inversion zweidimensionaler Leitfähigkeitsstrukturen in E-Polarisation. Habilitationsschrift, Math.-Nat. Fak. Univ. Göttingen.Google Scholar