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Crustal transect across the North Atlantic

  • R. MjeldeEmail author
  • T. Raum
  • A. J. Breivik
  • J. I. Faleide
Original Research Paper

Abstract

Two dimensional crustal models derived from four different ocean bottom seismographic (OBS) surveys have been compiled into a 1,580 km long transect across the North Atlantic, from the Norwegian Møre coast, across the extinct Aegir Ridge, the continental Jan Mayen Ridge, the presently active Kolbeinsey Ridge north of Iceland, into Scoresby Sund in East Greenland. Backstripping of the transect suggests that the continental break-up at ca. 55 Ma occurred along a west-dipping detachment localized near the western end of a ca. 300 km wide basin thinned to less than 20 km crustal thickness. It is likely that an east-dipping detachment near the present day Liverpool Land Escarpment was active during the late stages of continental rifting. A lower crustal high-velocity layer (7.2–7.4 km/s) interpreted as mafic intrusions/underplating, was present beneath the entire basin. The observations are consistent with the plume hypothesis, involving the Early Tertiary arrival of a mantle plume beneath central Greenland and focused decompression melting beneath the thinnest portions of the lithosphere. The mid-Eocene to Oligocene continental extension in East Greenland is interpreted as fairly symmetric and strongly concentrated in the lower crustal layer. Continental break-up which rifted off the Jan Mayen Ridge, occurred at ca. 25 Ma, when the Aegir Ridge became extinct. The first ca. 2 m.y. of oceanic accretion along the Kolbeinsey Ridge was characterized by thin magmatic crust (ca. 5.5 km), whereas the oceanic crustal formation since ca. 23 Ma documents ca. 8 km thick crust and high magma budget.

Keywords

Crustal transect North Atlantic OBS data Crustal evolution 

Notes

Acknowledgements

The crew of R/V Håkon Mosby and engineers from the University of Bergen are greatly acknowledged for their skills and help in acquiring the OBS data from the Norwegian Coastline to the Kolbeinsey Ridge. We also thank H. Shimamura, H. Shiobara, S. Kodaira, Y. Murai and engineers from Hokkaido University for invaluable participation in planning and executing these surveys, as well as for initial processing of the OBS data, and we thank Beata Mjelde for drawing figures. The Norwegian Petroleum Directorate (NPD), Statoil and Norsk Hydro funded these projects, and we thank in particular to E. Bråstein and H. Brekke (NPD), S. Thorbjørnsen (Statoil), as well as G. Haatvedt and R. Karpuz (Hydro). The modeling was done with help of the inversion/forward modeling software developed by C. Zelt (Rice University, Houston). The present paper can to a large extent be attributed to the fruitful environment for scientific discussions the first author experienced during a research stay in 2006 at SOEST, University of Hawaii. The paper was finalized during a research stay in 2007 at Institute for Seismology and Volcanology, Hokkaido University. We finally thank Peter Clift and two anonymous reviewers for very constructive comments.

References

  1. Breivik AJ, Mjelde R, Grogan P, Shimamura H, Murai Y, Nishimura Y (2003) Crustal structure and transform margin development south of Svalbard based on ocean bottom seismometer data. Tectonophysics 369:37–70CrossRefGoogle Scholar
  2. Breivik AJ, Mjelde R, Faleide JI, Murai Y (2006) Rates of continental break-up magmatism and seafloor spreading in the Norway Basin—constraints on Iceland plume activity. J Geophys Res 111:1–17CrossRefGoogle Scholar
  3. Brekke H (2000) The tectonic evolution of the Norwegian Sea continental margin, with emphasis on the Vøring and Møre Basins. In: Nøttvedt A (ed) Dynamics of the norwegian margin. Geological Society of London Special Publication 167, pp 327–378Google Scholar
  4. Christiansson P, Faleide JI, Berge AM (2000) Crustal structure in the northern North Sea: an integrated geophysical study. In: Nøttvedt A (ed) Dynamics of the norwegian margin. Geological Society of London Special Publication 167, pp 15–40Google Scholar
  5. Clift P, Lin J, Barckhausen U (2002) Evidence of low flexural rigidity and low viscosity lower continental crust during continental break-up in the South China Sea. Mar Pet Geol 19(8):951–970CrossRefGoogle Scholar
  6. Domenico SN (1984) Rock lithology and porosity determination from shear and compressional wave velocity. Geophysics 49:1188–1195CrossRefGoogle Scholar
  7. Eldholm O, Thiede J, Taylor E (1989) Evolution of the Vøring volcanic margin, Proc. ODP, Sci. Results 104, College Station, TX (Ocean Drilling Program), pp 1033–1065Google Scholar
  8. Flovenz OG (1980) Seismic structure of the Icelandic crust above layer three and the relation between body wave velocity and the alteration of the basaltic crust. J Geophys Res 47:211–220Google Scholar
  9. Foulger GR, Natland JH, Anderson DL (2005) A source for icelandic magmas in remelted Iapetus crust. J Volcanol Geotherm Res 141:23–44CrossRefGoogle Scholar
  10. Gernigon L, Ringenbach JS, Planke S, Le Gall B, Jonquet-Kolstø H (2003) Extension, crustal structure and magmatism at the outer Vøring Basin, Norwegian margin. J Geol Soc London 160:197–208CrossRefGoogle Scholar
  11. Holbrook WS, Mooney WD, Christensen J (1992) The seismic velocity structure of the deep continental crust. In: Fountain DM, Arculus R, Kay RW (eds) Continental lower crust, development in geotectonics, vol 23. Elsevier, Amsterdam, pp 1–43Google Scholar
  12. Holbrook WS, Larsen HC, Korenaga J, Dahl-Jensen T, Reid ID, Kelemen PB, Hopper JR, Kent GM, Lizarralde D, Bernstein S, Detrick RS (2001). Mantle thermal structure and active upwelling during continental breakup in the North Atlantic. Earth Planet Sci Lett 190:251–266CrossRefGoogle Scholar
  13. King SC, Anderson DL (1998) Edge-driven convection. Earth Planet Sci Lett 160:289–296CrossRefGoogle Scholar
  14. Kodaira S, Mjelde R, Shimamura H, Gunnarsson K, Shiobara H (1997) Crustal structure of the Kolbeinsey ridge, N. Atlantic, obtained by use of Ocean bottom seismographs. J Geophys Res 102:3131–3151CrossRefGoogle Scholar
  15. Kodaira S, Mjelde R, Gunnarsson K, Shiobara H, Shimamura H (1998) Structure of the Jan Mayen micro-continent and implications for its evolution. Geophys J Int 132:383–400CrossRefGoogle Scholar
  16. Kuvaas B, Kodaira S (1997) The formation of the Jan Mayen microcontinent: the missing piece in the continental puzzle between the Møre-Vøring Basins and East Greenland. First Break 15(7):239–247Google Scholar
  17. Mjelde R, Kodaira S, Shimamura H, Kanazawa T, Shiobara H, Berg EW, Riise O (1997) Crustal structure of the central part of the Vøring Basin, mid-Norway margin, from ocean bottom seismographs. Tectonophysics 277:235–257CrossRefGoogle Scholar
  18. Mjelde R, Aurvåg R, Kodaira S, Shimamura H, Gunnarsson K, Nakanishi A, Shiobara H (2002a) Vp/Vs-ratios from the central Kolbeinsey ridge to the Jan Mayen Basin, North Atlantic; implications on lithology, porosity and present-day stress field. Mar Geophys Res 23:125–145Google Scholar
  19. Mjelde R, Kasahara J, Shimamura H, Kamimura A, Kanazawa T, Kodaira S, Raum T, Shiobara H (2002b) Lower crustal seismic velocity-anomalies; magmatic underplating or serpentinized peridotite? Evidence from the Vøring margin, NE Atlantic. Mar Geophys Res 23:169–183CrossRefGoogle Scholar
  20. Mjelde R, Raum T, Digranes P, Shimamura H, Shiobara H, Kodaira S (2003) Vp/Vs-ratio along the Vøring margin, NE Atlantic, derived from OBS-data; implications on lithology and stress-field. Tectonophysics 369:175–197CrossRefGoogle Scholar
  21. Mjelde R, Eckhoff I, Solbakken S, Kodaira S, Shimamura H, Gunnarsson K, Nakanishi A, Shiobara H (2007) Gravity and S-wave modeling across the Jan Mayen ridge, North Atlantic; implications for crustal lithology and continental break-up processes. Mar Geophys Res 28:27–41CrossRefGoogle Scholar
  22. Mjelde R, Breivik AJ, Raum T, Mittelstaedt E, Ito G, Faleide JI (2008a) Magmatic and tectonic evolution of the North Atlantic. J Geol Soc London 164:1–12Google Scholar
  23. Mjelde R, Faleide JI, Breivik AJ, Raum T, Wilson J (2008b) Lower crustal composition and crustal lineaments on the Vøring margin, NE Atlantic. Tectonophysics (in press)Google Scholar
  24. Müller RD, Royer JY, Lawver LA (1993) Revised plate motions relative to the hotspots from combined Atlantic and Indian Ocean hotspot tracks. Geology 16:275–278CrossRefGoogle Scholar
  25. Mutter JC, Buck WR, Zehnder CM (1988) Convective partial melting, a model for the formation of thick basaltic sequences during the initiation of spreading. J Geophys Res 93:1031–1048CrossRefGoogle Scholar
  26. Mutter JC, Mutter CZ, Fang J (1996). Analogies to oceanic behaviour in the continental break-up of the western Woodlark Basin. Nature 380:333–336CrossRefGoogle Scholar
  27. Nunns AG (1983) Plate tectonic evolution of the Greenland-Scotland ridge and surrounding regions. In: Bott MHP, Saxow S, Talwani M, Thiede J (eds) Structure and development of the Greenland-Scotland ridge; new methods and concepts. Nato Adv. Res. Inst., Plenum Press, New York, pp 11–30Google Scholar
  28. Raum T (2000) Crustal structure and evolution of the Faroe, Møre and Vøring margins from wide-angle seismic and gravity data. Ph.D. thesis, University of Bergen, pp 114Google Scholar
  29. Raum T, Mjelde R, Shimamura H, Murai Y, Bråstein E, Karpuz RM, Kravik K, Kolstø HJ (2006) Crustal structure and evolution of the southern Vøring Basin and Vøring transform margin, NE Atlantic. Tectonophysics 415:167–202CrossRefGoogle Scholar
  30. Smallwood JR, White RS (1998) Crustal accretion at the Reykjanes ridge. J Geophys Res 103:5185–5201CrossRefGoogle Scholar
  31. Torsvik TH, Van der Voo R, Meert JG, Mosar J, Walderhaug HJ (2001) Reconstructions of the continents around the North Atlantic at about the 60th parallel. Earth Planet Sci Lett 187:55–69CrossRefGoogle Scholar
  32. Vogt PG, Johnson GL, Kristjansson L (1980) Morphology and magnetic anomalies North of Iceland. J Geophys 47:67–80Google Scholar
  33. Weigel W, Flüh ER, Miller H, Butzke A, Dehghani GA, Gebhardt V, Harder I, Hepper J, Jokat W, Kläschen D, Kreymann S, Schüßler S, Zhao Z (1995) Investigations of the East Greenland continental margin between 70° and 72°N by deep seismic sounding and gravity studies. Mar Geophys Res 17:167–199CrossRefGoogle Scholar
  34. White RS, McKenzie D (1989) Magmatism at rift zones: the generation of volcanic continental margins and flood basalts. J Geophys Res 94:7685–7729CrossRefGoogle Scholar
  35. White RS, McKenzie D, O’Nions J (1992) Oceanic crustal thickness from seismic measurements and rare earth element inversion. J Geophys Res 97:19683–19715CrossRefGoogle Scholar
  36. Zelt CA, Smith RB (1992) Seismic traveltime inversion for 2-D crustal velocity structure. Geophys J Int 108:16–34CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • R. Mjelde
    • 1
    Email author
  • T. Raum
    • 1
  • A. J. Breivik
    • 2
  • J. I. Faleide
    • 2
  1. 1.Department of Earth ScienceUniversity of BergenBergenNorway
  2. 2.Department of GeosciencesUniversity of OsloOsloNorway

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