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Magma-compensated crustal thinning in continental rift zones

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Abstract

Continental rift zones are long, narrow tectonic depressions in the Earth’s surface where the entire lithosphere has been modified in extension1. Rifting can eventually lead to rupture of the continental lithosphere and creation of new oceanic lithosphere or, alternatively, lead to formation of wide sedimentary basins around failed rift zones. Conventional models of rift zones include three characteristic features: surface manifestation as an elongated topographic trough, Moho shallowing due to crustal thinning, and reduced seismic velocity in the uppermost mantle due to decompression melting or heating from the Earth’s interior2,3,4. Here we demonstrate that only the surface manifestation is observed at the Baikal rift zone, whereas the crustal and mantle characteristics can be ruled out by a new seismic profile across southern Lake Baikal in Siberia. Instead we observe a localized zone in the lower crust which has exceptionally high seismic velocity and is highly reflective. We suggest that the expected Moho uplift was compensated by magmatic intrusion into the lower crust, producing the observed high-velocity zone. This finding demonstrates a previously unknown role for magmatism in rifting processes with significant implications for estimation of stretching factors and modelling of sedimentary basins around failed rift structures.

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Figure 1: Shaded relief topographic map and tectonic setting.
Figure 2: Model of seismic compressional velocity along the seismic profile across the BRZ.
Figure 3: Seismic sections across southern Lake Baikal with 8.0 km s-1 reduction velocity, with superimposed calculated travel times for the model in Fig. 2 .
Figure 4: Three models for formation of the BRZ superimposed on the seismic velocity model.

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References

  1. Olsen, K. H. (ed.) Continental Rifts: Evolution, Structure, Tectonics (Elsevier, 1995)

    Google Scholar 

  2. McKenzie, D. Some remarks on the development of sedimentary basins. Earth Planet. Sci. Lett. 40, 25–32 (1978)

    Article  ADS  Google Scholar 

  3. Wernicke, B. P. Uniform-sense normal simple shear of the continental lithosphere. Can. J. Earth Sci. 22, 108–125 (1985)

    Article  ADS  Google Scholar 

  4. Ruppel, C. Extensional processes in continental lithosphere. J. Geophys. Res. B 100, 24,187–24,215 (1995)

    Article  ADS  Google Scholar 

  5. Moore, T. C., Klitgord, K. D., Golmshtok, A. J. & Weber, E. Sedimentation and subsidence patterns in the central and north basins of Lake Baikal from seismic stratigraphy. Geol. Soc. Am. Bull. 109, 746–766 (1997)

    Article  ADS  Google Scholar 

  6. Zorin, Y. A. et al. The Baikal rift zone: The effect of mantle plumes on older structure. Tectonophysics 371, 153–173 (2003)

    Article  ADS  Google Scholar 

  7. Petit, C. & Deverchere, J. Structure and evolution of the Baikal rift: A synthesis. Geochem. Geophys. Geosyst. 7 10.1029/2006GC001265 (2006)

  8. Kiselev, A. I. Volcanism of the Baikal rift zone. Tectonophysics 143, 235–244 (1987)

    Article  ADS  CAS  Google Scholar 

  9. Achauer, U. & Masson, F. Seismic tomography of continental rifts revisited: From relative to absolute heterogeneities. Tectonophysics 358, 17–37 (2002)

    Article  ADS  Google Scholar 

  10. Windley, B. F. & Allen, M. B. Mongolian plateau: Evidence for a late Cenozoic mantle plume under central Asia. Geology 21, 295–298 (1993)

    Article  ADS  Google Scholar 

  11. Petit, C., Koulakov, I. & Deverchere, J. Velocity structure around the Baikal rift zone from teleseismic and local earthquake traveltimes and geodynamic implications. Tectonophysics 296, 125–144 (1998)

    Article  ADS  Google Scholar 

  12. Zhao, D. P., Lei, J. S., Inoue, T., Yamada, A. & Gao, S. S. Deep structure and origin of the Baikal rift zone. Earth Planet. Sci. Lett. 243, 681–691 (2006)

    Article  ADS  CAS  Google Scholar 

  13. Tapponier, P. & Molnar, P. Active faulting and Cenezoic tectonics of the Tien Shan, Mongolia, and Baykal regions. J. Geophys. Res. 84, 3425–3459 (1979)

    Article  ADS  Google Scholar 

  14. ten Brink, U. S. & Taylor, M. H. Crustal structure of central Lake Baikal: Insights into intracontinental rifting. J. Geophys. Res. 107 (B7). 10.1029/2001JB000300 (2002)

  15. Ionov, D. Mantle structure and rifting processes in the Baikal-Mongolia region: Geophysical data and evidence from xenoliths in volcanic rocks. Tectonophysics 351, 41–60 (2002)

    Article  ADS  CAS  Google Scholar 

  16. Gao, S. S., Liu, K. H. & Chen, C. Significant crustal thinning beneath the Baikal rift zone: New constraints from receiver function analysis. Geophys. Res. Lett. 31, L20610 (2004)

    Article  ADS  Google Scholar 

  17. Suvorov, V. D. et al. Structure of the crust in the Baikal rift zone and adjacent areas from Deep Seismic Sounding data. Tectonophysics 351, 61–74 (2002)

    Article  ADS  Google Scholar 

  18. Thybo, H., Maguire, P. K. H., Birt, C. & Perchuc, E. Seismic reflectivity and magmatic underplating beneath the Kenya Rift. Geophys. Res. Lett. 27, 2745–2748 (2000)

    Article  ADS  Google Scholar 

  19. Lyngsie, S. B., Thybo, H. & Lang, R. Rifting and lower crustal reflectivity: A case study of the intracratonic Dniepr-Donets rift zone, Ukraine. J. Geophys. Res. 112 B12402 10.1029/2006JB004795 (2007)

    Article  ADS  Google Scholar 

  20. Artemieva, I. M. & Mooney, W. D. Thermal thickness and evolution of Precambrian lithosphere: A global study. J. Geophys. Res. 106 (B8). 16387–16414 (2001)

    Article  ADS  Google Scholar 

  21. Gerya, T. V. & Burg, J. P. Intrusion of ultramafic magmatic bodies into the continental crust: Numerical simulation. Phys. Earth Planet. Inter. 160, 124–142 (2007)

    Article  ADS  Google Scholar 

  22. Prodehl, C. et al. Large-scale variation in lithospheric structure along and across the Kenya Rift. Nature 354, 223–227 (1991)

    Article  Google Scholar 

  23. Green, W. V., Achauer, U. & Meyer, R. P. A three-dimensional seismic image of the crust and upper mantle beneath the Kenya Rift. Nature 354, 199–203 (1991)

    Article  ADS  Google Scholar 

  24. Wilson, D. et al. Lithospheric structure of the Rio Grande rift. Nature 433, 851–855 (2005)

    Article  ADS  CAS  Google Scholar 

  25. White, R. & McKenzie, D. Magmatism at rift zones — the generation of volcanic continental margins and flood basalts. J. Geophys. Res. 94 (B6). 7685–7729 (1989)

    Article  ADS  Google Scholar 

  26. Barry, T. L. et al. Petrogenesis of Cenozoic basalts from Mongolia: Evidence for the role of asthenospheric versus metasomatized lithospheric mantle sources. J. Petrol. 44, 55–91 (2003)

    Article  ADS  CAS  Google Scholar 

  27. Raum, T. et al. Crustal structure and evolution of the southern Voring basin and Voring transform margin, NE Atlantic. Tectonophysics 415, 167–202 (2006)

    Article  ADS  Google Scholar 

  28. White, R. S., Smith, L. K., Roberts, A. W., Christie, P. A. F. & Kusznir, N. J. Lower-crustal intrusion on the North Atlantic continental margin. Nature 452, 460–464 (2008)

    Article  ADS  CAS  Google Scholar 

  29. Korenaga, J., Kelemen, P. B. & Holbrook, W. S. Methods for resolving the origin of large igneous provinces from crustal seismology. J. Geophys. Res. 107 (B9). 10.1029/2001JB001030 (2002)

  30. Furlong, K. P. & Fountain, D. M. Continental crustal underplating — thermal considerations and seismic-petrologic consequences. J. Geophys. Res. 91 (B8). 8285–8294 (1986)

    Article  ADS  Google Scholar 

  31. Delvaux, D. et al. Paleostress reconstructions and geodynamics of the Baikal region, Central Asia. Part 2. Cenozoic rifting. Tectonophysics 282, 1–38 (1997)

    Article  ADS  Google Scholar 

  32. Jin, S. G., Park, P. H. & Zhu, W. Y. Micro-plate tectonics and kinematics in Northeast Asia inferred from a dense set of GPS observations. Earth Planet. Sci. Lett. 257, 486–496 (2007)

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

This study received support from the Carlsberg Foundation and the Danish Natural Science Research Council. The field work at Lake Baikal further received support from the Russian Academy of Sciences, Siberian Branch, and the Polish Academy of Sciences. The seismic instruments were provided by the University of Copenhagen and the Technical University of Vienna. We acknowledge discussions with R. S. White on melting processes, and comments received from I. Artemieva, I. Reid and W. Stratford on earlier versions of the manuscript.

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  1. Department of Geography and Geology, University of Copenhagen, Oester Voldgade 10, DK-1350 Copenhagen K, Denmark,

    H. Thybo & C. A. Nielsen

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  1. H. Thybo
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  2. C. A. Nielsen
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Correspondence to H. Thybo.

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Thybo, H., Nielsen, C. Magma-compensated crustal thinning in continental rift zones. Nature 457, 873–876 (2009). https://doi.org/10.1038/nature07688

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