1887
  1. Home
  2. A-Z Publications
  3. Basin Research
  4. Volume 22, Issue 4
  5. Article
Volume 22 Number 4
  • E-ISSN: 1365-2117

Abstract

ABSTRACT

This paper documents a large number of large km‐scale fluid escape pipes with complex seismic expression and a diatreme‐like geometry from the mapping of a 3D seismic survey, offshore Namibia. These pipes are crudely cylindrical, but occasionally have steep conical geometry either narrowing upwards or downwards. They are generally ovoid in planform and their ellipticity varies with pipe height. Vertical dimensions range from . 100 to >1000 m and diameters range between 50 and 600 m. The lower part of the typical pipe is characterised by a sag‐like or collapse type of structure, but this is only imaged well in the wider pipes. The upper part of the typical pipe is characterised by gently concave upwards reflections, with a negative relief of tens of metres. There is some evidence (pipe cross‐section geometrical variations and amplitude anomalies) that these concave upwards reflections are vertically stacked palaeo‐pockmarks. A conceptual model for pipe formation is proposed that involves hydraulic fracturing and localisation of focused vertical fluid escape with volume loss at the base of the pipe inducing collapse within the pipe. Continuing episodic fluid migration through the pipe produces further collapsing of the core of the pipe and pockmark structures at the top of the pipe. Longer term seepage through pipes is manifested in zones of amplification of reflections above the top of the pipe.

© 2010 The Authors. Journal Compilation © Blackwell Publishing Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Loading

Article metrics loading...

/content/journals/10.1111/j.1365-2117.2010.00461.x
2010-02-17
2024-04-20

  • From This Site

    /content/journals/10.1111/j.1365-2117.2010.00461.x
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Aizawa, M., Bluck, B., Cartwright, J., Milner, S., Swart, R. & Ward, J. (2000) Constraints on the geomorphological evolution of Namibia from the offshore stratigraphic record. Commun. Geol. Surv. Namibia, 12, 337–346.
    [Google Scholar]
  2. Arntsen, B., Wensaas, L., Løseth, H. & Hermanrud, C. (2007) Seismic modeling of gas chimneys. Geophysics, 72, SM251–SM259.
    [Google Scholar]
  3. AustinJr., J.A. & Uchupi, E. (1982) Continental‐ oceanic crustal transition off southwest Africa. Am. Assoc. Petrol. Geol. Bull., 66, 1328–1347.
    [Google Scholar]
  4. Bagguley, J. & Prosser, S. (1999) The interpretation of passive margin depositional processes using seismic stratigraphy: examples from offshore Namibia. Geol. Soc. Spec. Publ., 153, 321–344.
    [Google Scholar]
  5. Baraza, J. & Ercilla, G. (1996) Gas‐charged sediments and large pockmark‐like features on the Gulf of Cadiz slope (SW Spain). Mar. Petrol. Geol., 13, 253–261.
    [Google Scholar]
  6. Berger, W.H., Lange, C.B. & Wefer, G. (2002) Upwelling history of the Benguela‐Namibia system: a synthesis of leg 175 results. In: Proceedings of the ODP, Initial Reports, Vol. 175 (Ed. by G.Wefer , W.H.Berger & C.Richter ), ODP, Texas pp. 1–103.
    [Google Scholar]
  7. Berndt, C., Bunz, S. & Mienert, J. (2003) Polygonal fault systems on the mid‐Norwegian margin: a long‐term source for fluid flow. In: Subsurface Sediment Mobilization (Ed. by P.Van Rensbergen , R.R.Hiollis , A.J.Maltman & C.K.Morley ), Geol. Soc. Spec. Publ., 216, 283–290.
    [Google Scholar]
  8. Bertoni, C. & Cartwright, J.A. (2005) 3D seismic analysis of circular evaporite dissolution structures, Eastern Mediterranean. J. Geol. Soc., 162, 909–926.
    [Google Scholar]
  9. Bluck, B.J., Ward, J.D., Cartwright, J. & Swart, R. (2007) The Orange River, southern Africa: an extreme example of a wave-dominated sediment dispersal system in the South Atlantic Ocean. J. Geol. Soc., 164, 341–351.
    [Google Scholar]
  10. Bouriak, S., Vanneste, M. & Saoutkine, A. (2000) Inferred gas hydrates and clay diapirs near the Storegga Slide on the southern edge of the Voring Plateau, offshore Norway. Mar. Geol., 163, 125–148.
    [Google Scholar]
  11. Branney, M.J. (1995) Downsag and extension at calderas: new perspectives on collapse geometries from ice-melt, mining, and volcanic subsidence. Bul. Volcanol., 57, 303–318.
    [Google Scholar]
  12. Brown, A.R. (2004) Interpretation of three‐dimensional seismic data, Canada. AAPG Mem., 42, 541.
    [Google Scholar]
  13. Brown, K.M.1990The nature and hydrogeologic significance of mud diapirs and diatremes for accretionary systems. J. Geophys. Res., 95, 8969–8982.
    [Google Scholar]
  14. Bünz, S., Mienert, J. & Berndt, C. (2003) Geological controls on the Storegga gas‐hydrate system of the mid‐Norwegian continental margin. Earth Planet. Sci. Lett., 209, 291–307.
    [Google Scholar]
  15. Cartwright, J., Huuse, M. & Aplin, A. (2007) Seal bypass systems. AAPG Bull., 91, 1141–1166.
    [Google Scholar]
  16. Cartwright, J., Swart, R., Corner, B., Bluck, B. & Ward, J. (2008) Offshore stratigraphy of Namibia. In: The Geology of Namibia (Ed. by R.Mc G.Millar ), Namibian Geol. Surv. Mem., 2, 59–72.
    [Google Scholar]
  17. Cartwright, J.A. & Dewhurst, D.N. (1998) Layer‐bound compaction faults in fine‐grained sediments. Bull. Geol. Soc. Am., 110, 1242–1257.
    [Google Scholar]
  18. Çifçi, G., Dondurur, D. & Ergün, M. (2003) Deep and shallow structures of large pockmarks in the Turkish shelf, Eastern Black Sea. Geo-Mar. Lett., 23, 311–322.
    [Google Scholar]
  19. Clemson, J., Cartwright, J. & Booth, J. (1997) Structural segmentation and the influence of basement structure on the Namibian passive margin. J. Geol. Soc., 154, 477–482.
    [Google Scholar]
  20. Clemson, J., Cartwright, J. & Swart, R. (1999) The Namib rift: a rift system of possible Karoo age, offshore Namibia. Geol. Soc. Spec. Publ., 153, 381–402.
    [Google Scholar]
  21. Cunningham, R. & Lindholm, R.M. (2000) Seismic evidence for widespread gas hydrate formationoffshore West Africa. AAPG Memoir., 73, 93–105.
    [Google Scholar]
  22. Dangerfield, J.A. (1992) Ekofisk field development: making images of a gas obscured reservoir. In: Reservoir Geophysics SEG (Ed. by R.E.Sheriff ), SEG, Tulsa UK pp. 98–109.
    [Google Scholar]
  23. Downey, M.W. (1984) Evaluating seals for hydrocarbon accumulation. AAPG Bull., 68, 1752–1763.
    [Google Scholar]
  24. England, P.C. (1987) Diffuse continental deformation: length scales, rates and metamorphic evolution. Philos. Trans. Royal Soc. London, A321, 1557–1577.
    [Google Scholar]
  25. Flemings, P.B., Liu, X. & Winters, W.J. (2003) Critical pressure and multiphase flow in Blake Ridge gas hydrates. Geology, 31, 1057–1060.
    [Google Scholar]
  26. Gay, A., Lopez, M., Berndt, C. & Séranne, M. (2007) Geological controls on focussed fluid flow associated with seafloor seeps in the Lower Congo Basin. Mar. Geol., 244, 68–92.
    [Google Scholar]
  27. Gay, A., Lopez, M., Cochonat, P., Levaché, D., Sermondadaz, G. & Seranne, M. (2006a) Evidences of early to late fluid migration from an upper Miocene turbiditic channel revealed by 3D seismic coupled to geochemical sampling within seafloor pockmarks, Lower Congo Basin. Mar. Petrol. Geol., 23, 387–399.
    [Google Scholar]
  28. Gay, A., Lopez, M., Cochonat, P., Séranne, M., Levaché, D. & Sermondadaz, G. (2006b) Isolated seafloor pockmarks linked to BSRs, fluid chimneys, polygonal faults and stacked Oligocene–Miocene turbiditic palaeochannels in the Lower Congo Basin. Mar. Geol., 226, 25–40.
    [Google Scholar]
  29. Gay, A., Lopez, M., Cochonat, P., Sultan, N., Cauquil, E. & Brigaud, F. (2003) Sinuous pockmark belt as indicator of a shallow buried turbiditic channel on the lower slope of the Congo basin, West African margin. In: Subsurface Sediment Mobilization (Ed. by P.Van Rensbergen , R.R.Hiollis , A.J.Maltman & C.K.Morley ), Geol. Soc. Spec. Publ., 216, 173–189.
    [Google Scholar]
  30. Gladczenko, T.P., Skogseid, J. & Eldhom, O. (1998) Namibia volcanic margin. Mar. Geophys. Res., 20, 313–341.
    [Google Scholar]
  31. Gorman, A.R., Holbrook, W.S., Hornbach, M.J., Hackwith, K.L., Lizarralde, D. & Pecher, I. (2002) Migration of methane gas through the hydrate stability zone in a low‐flux hydrate province. Geology, 30, 327–330.
    [Google Scholar]
  32. Goudie, A.S. (2005) The drainage of Africa since the Cretaceous. Geomorphology, 67, 437–456.
    [Google Scholar]
  33. Granli, J.R., Arntsen, B., Sollid, A. & Hilde, E. (1999) Imaging through gas‐filled sediments using marine shear‐wave data. Geophysics, 64, 668–677.
    [Google Scholar]
  34. Guiraud, R. & Maurin, J.C. (1992) Early Cretaceous rifts of Western and Central Africa: an overview. Tectonophysics, 213, 153–168.
    [Google Scholar]
  35. Hanken, N., Rønholt, G. & Hovland, M. (1999) Dannelsen av “Blow‐out pipes” basert på studier av Plio‐Pleistocene sedimenter på Rhodos (Abstract in Norwegian), Norwegian Geological Union, Vintermøte, Conference Proceedings: Stavanger, Norway. January 6–8, p. 52.
  36. Hansen, D.M. (2006) The morphology of intrusion‐related vent structures and their implications for constraining the timing of intrusive events along the NE Atlantic margin. J. Geol. Soc., 163, 789–800.
    [Google Scholar]
  37. Holm, N.G. & Charlou, J.L. (2001) Initial indications of abiotic formation of hydrocarbons in the Rainbow ultramafic hydrothermal system, Mid‐Atlantic Ridge. Earth Planet. Sci. Lett., 191, 1–8.
    [Google Scholar]
  38. Holtar, E. & Forsberg, A.W. (2000) Postrift development of the Walvis Basin, Namibia: results from the exploration campaign in Quadrant 1911. AAPG Mem., 73, 429–446.
    [Google Scholar]
  39. Hopkins, A.E. (2006) Seismic stratigraphic interpretation of contourite systems, Namibian continental margin. PhD Thesis, University of Cardiff, Cardiff.
  40. Hovland, M. & Judd, A.G. (1988) Seabed Pockmarks and Seepages: Impact on Geology, Biology and the Marine Environment. Graham & Trotman, London.
    [Google Scholar]
  41. Hovland, M. & Svensen, H. (2006) Submarine pingoes: indicators of shallow gas hydrates in a pockmark at Nyegga, Norwegian Sea. Mar. Geol., 228, 15–23.
    [Google Scholar]
  42. Hovland, M., Svensen, H., Forsberg, C.F., Johansen, H., Fichler, C., Fossa, J.H., Jonsson, R. & Rueslåtten, H. (2005) Complex pockmarks with carbonate‐ridges off mid‐Norway: products of sediment degassing. Mar. Geol., 218, 191–206.
    [Google Scholar]
  43. Hustoft, S., Mienert, J., Bünz, S. & Nouze, H. (2007) High‐resolution 3D‐seismic data indicate focussed fluid migration pathways above polygonal fault systems of the mid‐Norwegian margin. Mar. Geol., 245, 89–106.
    [Google Scholar]
  44. Judd, A.G. & Hovland, M. (2007) Seabed Fluid Flow: The Impact on Geology, Biology and the Marine Environment. Cambridge University Press, Cambridge.
    [Google Scholar]
  45. Karner, G.D., Driscoll, N.W. & Barker, D.H.N. (2003) Syn‐rift regional subsidence across the West African continental margin: the role of lower plate ductile extension. Geol. Soc. Spec. Publ., 207, 105–129.
    [Google Scholar]
  46. Kieft, T.L., McCuddy, S.M., Onstott, T.C., Davidson, M., Lin, L.H., Mislowack, B., Pratt, L., Boice, E., Lollar, B.S., Lippmann‐Pipke, J., Pfiffner, S.M., Phelps, T.J., Gihring, T., Moser, D. & Van Heerden, A. (2005) Geochemically generated, energy‐rich substrates and indigenous microorganisms in deep, ancient groundwater. Geomicrobiol. J., 22, 325–335.
    [Google Scholar]
  47. King, L.H. & MacLean, B. (1970) Pockmarks on the Scotian shelf. Geol. Soc. Am. Bull., 81, 3141–3148.
    [Google Scholar]
  48. Light, M.P.R., Maslanyj, M.P., Greenwood, R.J. & Banks, N.L. (1993) Seismic sequence stratigraphy and tectonics offshore Namibia. Geol. Soc. Spec. Publ., 71, 163–191.
    [Google Scholar]
  49. Ligtenberg, J.H. (2005) Detection of Fluid migration pathways in seismic data: implications for fault seal analysis. Basin Res., 17, 141–153.
    [Google Scholar]
  50. Lollar, B.S., Lacrampe‐Couloume, G., Slater, G.F., Ward, J., Moser, D.P., Gihring, T.M., Lin, L.H. & Onstott, T.C. (2006) Unravelling abiogenic and biogenic sources of methane in the Earth's deep subsurface. Chem. Geol., 226, 328–339.
    [Google Scholar]
  51. Loncke, L. & Mascle, J. (2004) Mud volcanoes, gas chimneys, pockmarks and mounds in the Nile deep‐sea fan (Eastern Mediterranean): geophysical evidences. Mar. Petrol. Geol., 21, 669–689.
    [Google Scholar]
  52. Løseth, H., Gading, M. & Wensaas, L. (2009) Hydrocarbon leakage interpreted on seismic data. Mar. Petrol. Geol., 26, 1304–1319.
    [Google Scholar]
  53. Løseth, H., Wensaas, L., Arntsen, B., Hanken, N., Basire, C. & Graue, K. (2001) 1000 m long gas blow out pipes. 63rd EAGE Conference and Exhibition, Extended Abstracts, 524p.
  54. Løseth, H., Wensaas, L., Arntsen, B. & Hovland, M. (2003) Gas and fluid injection triggering shallow mud mobilization in the Hordaland Group, North Sea. In: Subsurface Sediment Mobilization (Ed. by P.Van Rensbergen , R.R.Hiollis , A.J.Maltman & C.K.Morley ), Geol. Soc. Spec. Publ., 216, 139–157.
  55. Maslanyj, M.P., Light, M.P.R., Greenwood, R.J. & Banks, N.L. (1992) Extension tectonics offshore Namibia and evidence for passive rifting in the South Atlantic. Mar. Petrol. Geol., 9, 590–601.
    [Google Scholar]
  56. Mazzotti, L., Segantini, S., Tramontana, M. & Wezel, F.C. (1987) Characteristics of pockmarks on the Jabuka Trough floor (central Adriatic Sea). Boll. Oceanol. Teor. Appl., 5, 237–250.
    [Google Scholar]
  57. McCallum, M.E. (1985) Experimental evidence for fluidization processes in Breccia pipe formation. Econom. Geol., 80, 1523–1543.
    [Google Scholar]
  58. McDonnell, A., Loucks, R.G. & Dooley, T. (2007) Quantifying the origin and geometry of circular sag structures in northern Fort Worth Basin, Texas: Paleocave collapse, pull-apart fault systems, or hydrothermal alteration? AAPG Bull., 91, 1295–1318.
    [Google Scholar]
  59. Mienert, J. & Posewang, J. (1999) Evidence of shallow‐ and deep‐water gas hydrate destabilizations in North Atlantic polar continental margin sediments. Geo-Mar. Lett., 19, 143–149.
    [Google Scholar]
  60. Mienert, J., Posewang, J. & Baumann, M. (1998) Gas hydrates along the northeastern Atlantic margin: possible hydrate- bound margin instabilities and possible release of methane. Geol. Soc. Spec. Publ., 137, 275–291.
    [Google Scholar]
  61. Nürnberg, D. & Müller, R.D. (1991) The tectonic evolution of the South Atlantic from Late Jurassic to present. Tectonophysics, 191, 27–53.
    [Google Scholar]
  62. O'Brien, J. (2004) Seismic amplitudes from low gas saturation sands. Leading Edge (Tulsa, OK), 23, 1236–1243.
    [Google Scholar]
  63. Paull, C.K., Ussler Iii, W., Holbrook, W.S., Hill, T.M., Keaten, R., Mienert, J., Haflidason, H., Johnson, J.E., Winters, W.J. & Lorenson, T.D. (2008) Origin of pockmarks and chimney structures on the flanks of the Storegga slide, offshore Norway. Geo-Mar. Lett., 28, 43–51.
    [Google Scholar]
  64. Pecher, I.A., Kukowski, N., Huebscher, C., Greinert, J. & Bialas, J. (2001) The link between bottom‐simulating reflections and methane flux into the gas hydrate stability zone – new evidence from Lima Basin, Peru margin. Earth Planet. Sci. Lett., 185, 343–354.
    [Google Scholar]
  65. Rabinowitz, P.D. & Labrecque, J. (1979) The Mesozoic South Atlantic ocean and evolution of its continental margins. J. Geophys. Res., 84, 5973–6002.
    [Google Scholar]
  66. Riedel, M., Novosel, I., Spence, G.D., Hyndman, R.D., Chapman, R.N., Solem, R.C. & Lewis, T. (2006) Geophysical and geochemical signatures associated with gas hydrate‐related venting in the northern Cascadia margin. Bull. Geol. Soc. Am., 118, 23–38.
    [Google Scholar]
  67. Roussel, E.G., Bonavita, M.A.C., Querellou, J., Cragg, B.A., Webster, G., Prieur, D. & Parkes, R.J. (2008) Extending the sub‐sea‐floor biosphere. Science, 320, 1046.
    [Google Scholar]
  68. Sibson, R.H. (1995) Selective fault reactivation during basin inversion: potential for fluid redistribution through fault-valve action. Geol. Soc. Spec. Publ., 88, 3–19.
    [Google Scholar]
  69. Sleep, N.H., Meibom, A., Fridriksson, T., Coleman, R.G. & Bird, D.K. (2004) H2‐rich fluids from serpentinization: geochemical and biotic implications. Proc. Natl. Acad. Sci.USA, 101, 12818–12823.
    [Google Scholar]
  70. Summerfield, M.A. (1991) Global Geomorphology: An Introduction to the Study of Landforms. Longman Scientific & Technical, New York.
    [Google Scholar]
  71. Swart, R. (2009) Hydrate occurrences in the Namibe Basin, offshore Namibia. Geol. Soci. Spec. Publ., 319, 73–80.
    [Google Scholar]
  72. Thorsen, C.E (1963) Age of growth faulting in the southeast Louisiana. Trans. Gulf Coast Assoc. Geol. Soc., 13, 103–110.
    [Google Scholar]
  73. Tréhu, A.M., Flemings, P.B., Bangs, N.L., Chevallier, J., Gracia, E., Johnson, J.E., Liu, C.‐S., Liu, X., Riedel, M. & Torres, M.E. (2004) Feeding methane vents and gas hydrate deposits at south Hydrate Ridge. Geophys. Res. Lett., 31, 1–4.
    [Google Scholar]
  74. Trincardi, F., Cattaneo, A., Correggiari, A. & Ridente, D. (2004) Evidence of soft sediment deformation, fluid escape, sediment failure and regional weak layers within the late quaternary mud deposits of the Adriatic Sea. Mar. Geol., 213, 91–119.
    [Google Scholar]
  75. Van Rensbergen, P., Morley, C.K., Ang, D.W., Hoan, T.Q. & Lam, N.T. (1999) Structural evolution of shale diapirs from reactive rise to mud volcanism: 3D seismic data from the Baram delta, offshore Brunei Darussalam. J. Geol. Soc., 156, 633–650.
    [Google Scholar]
  76. Van Rensbergen, P.V., Rabaute, A., Colpaert, A., Ghislain, T.S., Mathijs, M. & Bruggeman, A. (2007) Fluid migration and fluid seepage in the Connemara field, porcupine basin interpreted from industrial 3D seismic and well data combined with high‐resolution site survey data. Int. J. Earth Sci., 96, 185–197.
    [Google Scholar]
  77. Watts, N.L. (1987) Theoretical aspects of cap‐rock and fault seals for single‐ and two‐phase hydrocarbon columns. Mar. Petrol. Geol., 4, 274–307.
    [Google Scholar]
  78. Westbrook, G.K., Exley, R., Minshull, T.A., Nouze, H., Gailler, A., Jose, T., Ker, S. & Plaza, A. (2008) High‐resolution 3D seismic investigations of hydrate‐bearing fluid‐escape chimneys in the Nyegga region of the Voring Plateau, Norway: Vancouver BC, Canada. International Conference on Gas Hydrates, paper 5597.
  79. Whiticar, M.J. (1999) Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane. Chem. Geol., 161, 291–314.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1111/j.1365-2117.2010.00461.x
Loading
3D seismic expression of km‐scale fluid escape pipes from offshore Namibia
Basin Research 22, 481 (2010); https://doi.org/10.1111/j.1365-2117.2010.00461.x
/content/journals/10.1111/j.1365-2117.2010.00461.x
/content/journals/10.1111/j.1365-2117.2010.00461.x
Loading

Data & Media loading...

  • Article Type: Research Article

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error