1887
Volume 20 Number 4
  • E-ISSN: 1365-2117

Abstract

ABSTRACT

At convergent margins, the structure of the subducting oceanic plate is one of the key factors controlling the morphology of the upper plate. We use high‐resolution seafloor mapping and multichannel seismic reflection data along the accretionary Sumatra trench system to investigate the morphotectonic response of the upper plate to the subduction of lower plate fabric. Upper plate segmentation is reflected in varying modes of mass transfer. The deformation front in the southern Enggano segment is characterized by neotectonic formation of a broad and shallow fold‐and‐thrust belt consistent with the resumption of frontal sediment accretion in the wake of oceanic relief subduction. Conversely, surface erosion increasingly shapes the morphology of the lower slope and accretionary prism towards the north where significant oceanic relief is subducted. Subduction of the Investigator Fracture Zone and the fossil Wharton spreading centre in the Siberut segment exemplifies this. Such features also correlate with an irregularly trending deformation front suggesting active frontal erosion of the upper plate. Lower plate fabric extensively modulates upper plate morphology and the large‐scale morphotectonic segmentation of the Sumatra trench system is linked to the subduction of reactivated fracture zones and aseismic ridges of the Wharton Basin. In general, increasing intensity of mass‐wasting processes, from south to north, correlates with the extent of oversteepening of the lower slope (lower slope angle of 3.8° in the south compared with 7.6° in the north), probably in response to alternating phases of frontal accretion and sediment underthrusting. Accretionary mechanics thus pose a second‐order factor in shaping upper plate morphology near the trench.

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2008-09-17
2020-04-05
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References

  1. Abercrombie, R.E., Antolik, M. & Ekström, G. (2003) The June 2000 Mw 7.9 earthquakes south of Sumatra: deformation in the India-Australia plate. J. Geophys. Res., 108 (B1), 2018, doi: DOI: 10.1029/2001JB000674.
    [Google Scholar]
  2. Barckhausen, U. & SeaCause Scientific Party (2006) The segmentation of the subduction zone offshore Sumatra: relations between upper and lower plate, EOS Trans. AGU, 87(52), Fall Meet. Suppl., Abstract U53A‐0029.
  3. Cande, S.C., LaBrecque, J.L., Larson, R.L., Pitman, W.C., Golovchenko, X. & Haxby, W.F. (1989) Magnetic lineations of World's Ocean Basins. Amer. Ass. Petrol. Geol., Tulsa.
    [Google Scholar]
  4. Caress, D.W. & Chayes, D.N. (1996) Improved processing of Hydrosweep DS multibeam data on the R/V Maurice Ewing. Mar. Geophys. Res., 18, 631–650.
    [Google Scholar]
  5. Collot, J.‐Y. & Fisher, M.A. (1989) Formation of forearc basins by collision between seamounts and accretionary wedges: an example from the New Hebrides subduction zone. Geology, 17, 930–933.
    [Google Scholar]
  6. Davis, D., Suppe, J. & Dahlen, F.A. (1983) Mechanics of fold‐and‐thrust belts and accretionary wedges: cohesive coulomb theory. J. Geophys. Res., 88, 1153–1172.
    [Google Scholar]
  7. Deplus, C., Diament, M., Hébert, H., Bertrand, G., Dominguez, S., Dubois, J., Malod, J., Patriat, P., Pontoise, B. & Sibilla, J.‐J. (1998) Direct evidence of active deformation in the eastern Indian oceanic plate. Geology, 26, 131–134.
    [Google Scholar]
  8. Dominguez, S., Lallemand, S., Malavielle, J. & Schnuerle, P. (1998) Oblique subduction of the Gagua Ridge beneath the Ryukyu accretionary wedge system: insights from marine observations and sandbox experiments. Mar. Geophys. Res., 20, 383–402.
    [Google Scholar]
  9. Fisher, D., Mosher, D., Austin, J.A., Gulick, S., Masterlark, T. & Moran, K. (2007) Active deformation across the Sumatran forearc over the December 2004 Mw 9.2 rupture. Geology, 35 (2), 99–102, doi: DOI: 10.1130/G22993A.1.
    [Google Scholar]
  10. Franke, D., Schnabel, M., Ladage, S., Tappin, D.R., Neben, S., Djajadihardja, Y., Mueller, C., Kopp, H. & Gaedicke, C. (2008) The great Sumatra–Andaman earthquakes‐imaging the boundary between the ruptures of the great 2004 and 2005 earthquakes. Earth Planet. Sci. Lett., 269, 1–2, doi: DOI: 10.1016/j.epsl.2008.01.047.
    [Google Scholar]
  11. Gaedicke, C. (Ed). (2006) Cruise Report SO186 Leg 2 Seacause II, BGR Report, 0125999, 144pp.
  12. Gutscher, M.‐A., Kukowski, N., Malavielle, J. & Lallemand, S. (1998) Episodic imbricate thrusting and underthrusting: analog experiments and mechanical analysis applied to the Alaskan Accretionary Wedge. J. Geophys. Res., 103, 10161–10176.
    [Google Scholar]
  13. Hampel, A. (2002) The migration history of the Nazca Ridge along the Peruvian active margin: a re-evaluation. Earth Planet. Sci. Lett., 203, 665–679.
    [Google Scholar]
  14. Hampel, A., Adam, J. & Kukowski, N. (2004) Response of the tectonically erosive south Peruvian forearc to subduction of the Nazca Ridge, Analysis of three‐dimensional analogue experiments. Tectonics, 23, TC5003, doi: DOI: 10.1029/2003TC001585.
    [Google Scholar]
  15. Hébert, H. (1998) Etudes géophysiques d'une dorsale naissante (dorsale d'Aden à l'Ouest de 46°E) et d'une dorsale fossile (dorsale de Wharton): implications sur les processus de l'accrétion océanique, et la deformation intraplaque de l'Océan Indien, PhD Thesis, University of Paris, 372pp.
  16. Henstock, T.J., McNeill, L.C. & Tappin, D.R. (2006) Seafloor morphology of the Sumatran subduction zone: surface rupture during megathrust earthquakes? Geology, 34, 485–488.
    [Google Scholar]
  17. Kopp, H. & Flueh, E.R. (Eds). (2006) Cruise Report SO186 Leg 3 Seacause II, IFM‐GEOMAR Rep., 6, 205pp.
  18. Kopp, H., Flueh, E.R., Klaeschen, D., Bialas, J. & Reichert, C. (2001) Crustal structure of the central Sunda margin at the onset of oblique subduction. Geophys. J. Int., 147, 449–474.
    [Google Scholar]
  19. Kopp, H. & Kukowski, N. (2003) Backstop geometry and accretionary mechanics of the Sunda margin. Tectonics, 22 (6), 1072, doi: DOI: 10.1029/2002TC001420.
    [Google Scholar]
  20. Ladage, S., Weinrebe, W., Gaedicke, C., Barckhausen, U., Flueh, E.R., Heyde, I., Krabbenhoeft, A., Kopp, H., Fajar, S. & Djajadihardja, Y. (2006) Bathymetric survey images structure off Sumatra. EOS, 87 (17), 165–172.
    [Google Scholar]
  21. Lallemand, S., Schnürle, P. & Mallavielle, J. (1994) Coulomb theory applied to accretionary and nonaccretionary wedges: possible causes for tectonic erosion and/or frontal accretion. J. Geophys. Res., 99, 12033–12055.
    [Google Scholar]
  22. Laursen, J., Scholl, D.W. & Von Huene, R. (2002) Neotectonic deformation of the central Chile margin: deepwater forearc basin formation in response to hot spot and seamount subduction. Tectonics, 21 (5), 1038, doi: DOI: 10.1029/2001TC901023.
    [Google Scholar]
  23. Liu, C., Curray, J.R. & McDonald, J.M. (1983) New constraints on the tectonic evolution of the eastern Indian Ocean. Earth Planet. Sci. Lett., 65, 331–342.
    [Google Scholar]
  24. Mackay, S. & Abma, R. (1993) Depth focusing analysis using wavefront‐cruvature criterion. Geophysics, 58, 1148–1156.
    [Google Scholar]
  25. Moore, G.F. & Curray, J. (1980) Structure of the Sunda trench lower slope off Sumatra from multichannel seismic reflection data. Mar. Geophys. Res., 4, 319–340.
    [Google Scholar]
  26. Royer, J.Y. & Sandwell, D.T. (1989) Evolution of the eastern Indian ocean since late cretaceous: constraints from Geosat altimetry. J. Geophys. Res., 94, 13755–13782.
    [Google Scholar]
  27. Sandwell, D.T. & Smith, W.H.F. (1997) Marine gravity anomaly from Geosat and ERS‐1 altimetry. J. Geophys. Res., 102 (B1), 10039–10054.
    [Google Scholar]
  28. Schlüter, H.U., Gaedicke, C., Roeser, H.A., Schreckenberger, B., Meyer, H., Reichert, C., Djajadihardja, Y. & Prexl, A. (2002) Tectonic features of the southern Sumatra‐western Java forearc of Indonesia. Tectonics, 21 (5), 1047, doi: DOI: 10.1029/2001TC901048.
    [Google Scholar]
  29. Stein, C.A., Cloethingh, S. & Wortel, R. (1989) Seasat‐derived gravity constraints on stress and deformation in the northeastern Indian Ocean. Geophys. Res. Lett., 16, 823–826.
    [Google Scholar]
  30. Von Huene, R., Klaeschen, D., Gutscher, M.‐A. & Fruehn, J. (1998) Mass and fluid flux during accretion at the Alaska margin. Geol. Soc. Am. Bull, 110 (4), 468–482.
    [Google Scholar]
  31. Wang, K. & Hu, Y. (2006) Accretionary prisms in subduction earthquake cycles: the theory of dynamic Coulomb wedge. J. Geophys. Res., 111, B06410, doi: DOI: 10.1029/2005JB004094.
    [Google Scholar]
  32. Wessel, P. & Smith, W.H.F. (1995) New Version of the Generic Mapping Tools Released, EOS Trans. AGU, 76, 329.
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