International Journal of Earth Sciences

, Volume 107, Issue 8, pp 2907–2929 | Cite as

Downslope-shifting pockmarks: interplay between hydrocarbon leakage, sedimentations, currents and slope’s topography

  • Sutieng Ho
  • Patrice Imbert
  • Martin Hovland
  • Andreas Wetzel
  • Jean-Philippe Blouet
  • Daniel Carruthers
Original Paper


Pockmarks in Pliocene-Quaternary continental slope deposits offshore Angola show features related to: (1) fluid leakage craters that formed repeatedly, (2) authigenic methane-derived carbonates that indicate the (former) presence of hydrocarbons and (3) erosional–depositional structures that are clearly related to current activity. Depending on topography, the pockmarks show differing development: “Advancing Pockmarks” preferentially developed on regional slopes or inclined topography (> 2.5°–3°). They arranged in a chain-like pattern and mimic the outline of buried turbidite channels below. These pockmarks and their infill migrated downslope in response to shifting vents. “Nested Pockmarks” occur in gently sloping areas (< 2°). Their isolated conical infill records slope-parallel migration within a specific depth range pointing to the influence of contour currents. Both pockmark types are long-lived and they record preferential fluid migration along specific pathways, which developed at the downcurrent sidewalls of pockmarks due to flow separation initiating “cavity flow” within the pockmarks. The durable specific migration paths include pockmark sidewalls, vertically stacked erosional-interface of sediment waves, or entire pockmark bodies. The vertical extent of both pockmark types from End Miocene to the present-day seafloor documents various intensities of episodic fluid bursts followed by periods of quiescence and fill.


Pockmark migration Pockmark infill Hydrocarbon leakage Angola 



We thank Total S.A. for providing data, funding and its partner for publication permission, and the Ministry of Science and Technology of Taiwan for the Grant MOST1052914I002069A1. Our work is based on and extended from S. Ho’s PhD. The scientific work was fully carried out in Total S.A. and under its direction. S. Ho thanks Benoit Paternoster for his supervision on Geophysics. S. Ho also thanks Cardiff University and JA Cartwright for his great interest in this work and general support. Thanks also for the advices and the enormous support from Gordon Lawrence, David Hutchings, Ludvig Löwemark, and Char-Shine Liu.


  1. Abelson A, Denny M (1997) Settlement of marine organisms in flow. Ann Rev Ecol Syst 28(1):317–339CrossRefGoogle Scholar
  2. Allen JRL (1984) Sedimentary structures, their character and physical basis (I + II). Elsevier, AmsterdamGoogle Scholar
  3. Andresen KJ, Huuse M (2011) ‘Bulls-eye’ pockmarks and polygonal faulting in the Lower Congo Basin: relative timing and implications for fluid expulsion during shallow burial. Mar Geol 279:111–127CrossRefGoogle Scholar
  4. Baraza J, Ercilla G (1996) Gas-charged sediments and large pockmark-like features on the Gulf of Cadiz slope (SW Spain). Mar Pet Geol 13:253–261CrossRefGoogle Scholar
  5. Benjamin U, Huuse M, Hodgetts D (2015) Canyon-confined pockmarks on the western Niger Delta slope. J Afr Earth Sc 107:15–27CrossRefGoogle Scholar
  6. Berger WH, Lange CB, Wefer G (2002) Upwelling history of the Benguela–Namibia system: a synthesis of Leg 175 results. Proc Ocean Drill Progr Sci Results 175:1–103Google Scholar
  7. Bøe R, Rise L, Ottesen D (1998) Elongate depressions on the southern slope of the Norwegian Trench (Skagerrak): morphology and evolution. Mar Geol 146:191–203CrossRefGoogle Scholar
  8. Brothers LL, Kelley JT, Belknap DF, Barnhardt WA, Andrews BD, Maynard ML (2011) More than a century of bathymetric observations and present-day shallow sediment characterization in Belfast Bay, Maine, USA: implications for pockmark field longevity. Geo-Mar Lett 31:237–248CrossRefGoogle Scholar
  9. Broucke O, Temple F, Rouby D, Robin C, Calassou S, Nalpas T, Guillocheau F (2004) The role of deformation processes on the geometry of mud-dominated turbiditic systems, Oligocene and Lower–Middle Miocene of the Lower Congo basin (West African Margin). Mar Pet Geol 21:327–348CrossRefGoogle Scholar
  10. Casas D, Ercilla G, Baraza J (2003) Acoustic evidences of gas in the continental slope sediments of the Gulf of Cadiz (E Atlantic). Geo Mar Lett 23:300–310CrossRefGoogle Scholar
  11. Cattaneo A, Correggiari A, Marsset T, Thomas Y, Marsset B, Trincardi F (2004) Seafloor undulation pattern on the Adriatic shelf and comparison to deep-water sediment waves. Mar Geol 213:121–148CrossRefGoogle Scholar
  12. Cauquil E, Adamy J (2008) Seabed imagery and chemosynthetic communities: examples from deep offshore West Africa. In: 2008 Offshore Technology Conference, pp 5–8Google Scholar
  13. Cauquil E, Stephane L, George R, Shyu J-P (2003) High-resolution autonomous underwater vehicle (AUV) geophysical survey of a large, deep water pockmark offshore Nigeria. In: 65th EAGE Conference and Exhibition, pp 56–59Google Scholar
  14. Çifçi G, Dondurur D, Ergün M (2003) Deep and shallow structures of large pockmarks in the Turkish shelf, Eastern Black Sea. Geo Mar Lett 23:311–322CrossRefGoogle Scholar
  15. Coffeen JA (1986) Seismic exploration fundamentals. Pennwell Books, TulsaGoogle Scholar
  16. Collinson JD, Thomson DB (1988) Sedimentary structures. Hyman and Allen, London, p 204Google Scholar
  17. Coterill K, Tari G, Valasek D, van Dyke S (2005) 3D Gulf of Guinea seismic images offer useful comparisons with offshore Morocco. World Oil 226:43Google Scholar
  18. Curzi PV, Veggiani A (1985) I pockmarks nel mare Adriatico. centrale. Acta Nat Ateneo Parmense 21:9–90Google Scholar
  19. Davies RJ (2003) Kilometer-scale fluidization structures formed during early burial of a deep-water slope channel on the Niger Delta. Geology 31:949–952CrossRefGoogle Scholar
  20. De Vries MH, Svanø G, Tjelta TI, Emdal AJ (2007) Pockmarks: created by reduced sedimentation or a sudden blow-out? In: Proceeding of the seventeenth international offshore and polar engineering conference. International Society of Offshore and Polar Engineers, Lison, pp 1361–1365Google Scholar
  21. Dimitrov L, Dontcheva V (1994) Seabed pockmarks in the southern Bulgarian Black Sea zone. Bull Geol Soc Den 41:24–33Google Scholar
  22. Dondurur D, Çifçi G (2009) Anomalous strong reflections on high resolution seismic data from the Turkish Shelf of the Eastern Black Sea: possible indicators of shallow hydrogen sulphide-rich gas hydrate layers. Turk J Earth Sci 18:299–313Google Scholar
  23. Fang L, Nicolaou D, Cleaver J (1999) Transient removal of a contaminated fluid from a cavity. Int J Heat Fluid Flow 20:605–613CrossRefGoogle Scholar
  24. Feng D, Chen D, Peckmann J, Bohrmann G (2010) Authigenic carbonates from methane seeps of the northern Congo fan: microbial formation mechanism. Mar Pet Geol 27:748–756CrossRefGoogle Scholar
  25. Gay A (2002) Les marqueurs géologiques de la migration et de l’expulsion des fluides sédimentaires sur le plancher des marges passives matures: exemples dans le bassin du Congo. Doctoral dissertation. University of Lille IGoogle Scholar
  26. 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. Geol Soc Lond Spec Publ 216:173–189CrossRefGoogle Scholar
  27. Gay A, Lopez M, Ondreas H, Charlou JL, Sermondadaz G, Cochonat P (2006) Seafloor facies related to upward methane flux within a Giant Pockmark of the Lower Congo Basin. Mar Geol 226:81–95CrossRefGoogle Scholar
  28. Gong C, Wang Y, Steel RJ, Peakall J, Zhao X, Sun Q (2016) Flow processes and sedimentation in unidirectionally migrating deep-water channels: From a three-dimensional seismic perspective. Sedimentology 63:645–661CrossRefGoogle Scholar
  29. Greenspan D (1969) Numerical studies of prototype cavity flow problems. Comput J 12:88–93CrossRefGoogle Scholar
  30. Gross TF, Williams AJ (1991) Characterisation of deep-sea storms. Mar Geol 99:281–301CrossRefGoogle Scholar
  31. Guillon S, Keskes N (2004) Sismage and the 3-D visualization at total. In: American Association of Petroleum Geologists International Conference, Cancun, Mexico, pp 24–27Google Scholar
  32. Haigermoser C, Vesely L, Novara M, Zuzio D, Onorato M (2007) Time-resolved PIV applied to cavity unsteady flows. AIAA Paper, 3432Google Scholar
  33. Haskell N, Nissen S, Whitman D, Antrim L (1997) Structural features on the West African continental slope delineated by 3D seismic coherency. Am Asso Pet Geol Bull 81:1382Google Scholar
  34. Heezen BC, Menzies RJ, Schneider ED, Ewing WM, Granelli NCL (1964) Congo submarine Canyon. Am Asso Pet Geol Bull 48:1126–1149Google Scholar
  35. Heiniö P, Davies RJ (2009) Trails of depressions and sediment waves along submarine channels on the continental margin of Espirito Santo Basin, Brazil. Geol Soc Am Bull 121:698–711CrossRefGoogle Scholar
  36. Henderson J (2001) Investigation of cavity flow aerodynamics using computational fluid dynamics. Doctoral dissertation. University of GlasgowGoogle Scholar
  37. Higdon JJ (1985) Stokes flow in arbitrary two-dimensional domains: shear flow over ridges and cavities. J Fluid Mech 159:195–226CrossRefGoogle Scholar
  38. Ho S (2013) [first submission; 2014 validated correction]. Evolution of complex vertical successions of fluid venting systems during continental margin sedimentation. Doctoral dissertation. Cardiff UniversityGoogle Scholar
  39. Ho S, Cartwright JA, Imbert P (2012a) Vertical evolution of fluid venting structures in relation to gas flux, in the Neogene-Quaternary of the Lower Congo Basin, Offshore Angola. Mar Geol 332:40–55CrossRefGoogle Scholar
  40. Ho S, Cartwright J, Imbert P (2012b) The formation of advancing pockmarks arrays: an interplay between hydrocarbon leakage and slope sedimentation. American Association of Petroleum Geologists Annual Convention and Exhibition, Long Beach, pp 22–25Google Scholar
  41. Ho S, Carruthers TD, Imbert P, Cartwright J (2013) Spatial variations in geometries of polygonal faults due to stress perturbations and interplay with fluid venting features. In: 75th EAGE Conference and Exhibition incorporating SPE EUROPEC 2013Google Scholar
  42. Ho S, Carruthers D, Imbert P (2016) Insights into the permeability of polygonal faults from their intersection geometries with linear chimneys: a case study from the Lower Congo Basin. Carnets de Géologie 16:17Google Scholar
  43. Hovland M (1981) A classification of pockmark related features in the Norwegian Trench. Continental Shelf Institute, IKU, Publication 106:28Google Scholar
  44. Hovland M (1984) Gas-induced erosion features in the North Sea. Earth Surf Proc Land 9:209–228CrossRefGoogle Scholar
  45. Hovland M, Judd A (1988) Seabed pockmarks and seepages: impact on geology, biology, and the marine environment. Graham and Trotman, LondonGoogle Scholar
  46. Hovland M, Talbot MR, Qvale H, Olaussen S, Aasberg L (1987) Methane-related carbonate cements in pockmarks of the North Sea. J Sediment Res 57:881–892Google Scholar
  47. Hovland M, Heggland R, De Vries MH, Tjelta TI (2010) Unit-pockmarks and their potential significance for predicting fluid flow. Mar Pet Geol 27:1190–1199CrossRefGoogle Scholar
  48. Hustoft S, Mienert J, Bünz S, Nouzé H (2007) High-resolution 3D-seismic data indicate focussed fluid migration pathways above polygonal fault systems of the mid-Norwegian margin. Mar Geol 245:89–106CrossRefGoogle Scholar
  49. Imbert P, Ho S (2012) Seismic-scale funnel-shaped collapse features from the Paleocene–Eocene of the North West Shelf of Australia. Mar Geol 332:198–221CrossRefGoogle Scholar
  50. Jobe ZR, Lowe DR, Uchytil SJ (2011) Two fundamentally different types of submarine canyons along the continental margin of Equatorial Guinea. Mar Pet Geol 28:843–860CrossRefGoogle Scholar
  51. Jopling AV (1965) Hydraulic factors controlling the shape of laminae in laboratory deltas. J Sediment Res 35:777–791Google Scholar
  52. Josenhans HW, King LH, Fader GB (1978) A side-scan sonar mosaic of pockmarks on the Scotian Shelf. Can J Earth Sci 15:831–840CrossRefGoogle Scholar
  53. Judd AG, Hovland M (2007) Seabed fluid flow: the impact of geology, biology and the marine environment. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  54. Kelley JT, Dickson SM, Belknap DF, Barnhardt WA, Henderson M (1994) Giant sea-bed pockmarks: evidence for gas escape from Belfast Bay. Maine Geol 22:59–62Google Scholar
  55. Larson RL, Ladd JW (1973) Evidence for the opening of the South Atlantic in the Early Cretaceous. Nature 246:209–212CrossRefGoogle Scholar
  56. Lavier LL, Steckler MS, Brigaud F (2001) Climatic and tectonic control on the Cenozoic evolution of the West African margin. Mar Geol 178:63–80CrossRefGoogle Scholar
  57. Liro LM, Dawson WC (2000) Reservoir systems of selected basins of the South Atlantic. In: Mello MR, Katz BJ (eds) Petroleum systems of South Atlantic margins, vol 73. American Association of Petroleum Geologists Memoir, Tulsa, pp 77–92Google Scholar
  58. Lutjeharms J, Meeuwis J (1987) The extent and variability of south-east Atlantic upwelling. S Afr J Mar Sci 5:51–62CrossRefGoogle Scholar
  59. Manley PL, Manley T, Watzin MC, Gutierrez J (2004) Lakebed pockmarks in Burlington Bay, Lake Champlain: I. Hydrodynamics and implications of origin. In: Manley TO, Manley PL, Mihuc TB (eds) Lake champlain: partnerships and research in the New Millennium. Springer, New York, pp 299–399CrossRefGoogle Scholar
  60. Maroga B (2008) Pockmarks of pliocene in the lower congo basin: morphology and mechanism of formation. (Les pockmarks du Pliocène du Bassin du Bas-Congo: Morphologie et mécanismes de mise en place). Master thesis, Université des Pays de lAdour Google Scholar
  61. Marton G, Tari L, Lehmann GC CT (2000) Evolution of the Angolan passive margin, West Africa, with emphasis on post-salt structural styles. Atlantic rifts and continental margins. Am Geophys Union 115:129–149Google Scholar
  62. Mascle J, Phillips JD (1972) Magnetic smooth zones in the South Atlantic. Nature 240:80–84CrossRefGoogle Scholar
  63. Mazzotti L, Segantini S, Tramontana M, Wezel FC (1987) Classification and distribution of pockmarks in the Jabuka Trough (central Adriatic). Bollettino de Oceanologia Teorica ed Applicata 5:237–250Google Scholar
  64. Migeon C, Texier A, Pineau G (2000) Effects of lid-driven cavity shape on the flow establishment phase. J Fluids Struct 14:469–488CrossRefGoogle Scholar
  65. Migeon S, Savoye B, Zanella E, Mulder T, Faugères JC, Weber O (2001) Detailed seismic-reflection and sedimentary study of turbidite sediment waves on the Var Sedimentary Ridge (SE France): significance for sediment transport and deposition and for the mechanisms of sediment-wave construction. Mar Pet Geol 18:179–208CrossRefGoogle Scholar
  66. Mitchum R Jr, Vail P, Thompson III, S (1977) Seismic stratigraphy and global changes of sea level: Part 2. The depositional sequence as a basic unit for stratigraphic analysis: Sect. 2. In: Payton CE (ed) Seismic stratigraphy: application to hydrocarbon exploration, vol 26. American Association of Petroleum Geologists Memoir, Tulsa, pp 53–62Google Scholar
  67. Moss JL (2010) The spatial and temporal distribution of pipe and pockmark formation. Doctor dissertation. Cardiff UniversityGoogle Scholar
  68. Nakajima T, Satoh M, Okamura Y (1998) Channel-levee complexes, terminal deep-sea fan and sediment wave fields associated with the Toyama deep-sea channel system in the Japan Sea. Mar Geol 147:25–41CrossRefGoogle Scholar
  69. Normark WR, Piper DJW, Posamentier H, Pirmez C, Migeon S (2002) Variability in form and growth of sediment waves on turbidite channel levees. Mar Geol 192:23–58CrossRefGoogle Scholar
  70. Nowell ARM, Jumars PA (1984) Flow environments of aquatic benthos. Ann Rev Ecol Syst 15:303–328CrossRefGoogle Scholar
  71. Pau M, Gisler G, Hammer Ø (2014) Experimental investigation of the hydrodynamics in pockmarks using particle tracking velocimetry. Geo Mar Lett 34:11–19CrossRefGoogle Scholar
  72. Paull CK, Ussler W III (2008) Re-evaluating the significance of seafloor accumulations of methane-derived carbonates: seepage or erosion indicators? In: Proceedings of the 6th International Conference on Gas Hydrates (ICGH 2008). Paper 5581Google Scholar
  73. Petersen CJ, Bünz S, Hustoft S, Mienert J, Klaeschen D (2010) High-resolution P-Cable 3D seismic imaging of gas chimney structures in gas hydrated sediments of an Arctic sediment drift. Mar Pet Geol 27:1981–1994CrossRefGoogle Scholar
  74. Pey YY, Chua LP, Siauw WL (2012) The characteristics of open cavity flow with a length to depth ratio of 4. WIT Trans Eng Sci 74:59–70CrossRefGoogle Scholar
  75. Pey YY, Chua LP, Siauw WL (2014) Effect of trailing edge ramp on cavity flow structures and pressure drag. Int J Heat Fluid Flow 45:53–71CrossRefGoogle Scholar
  76. Philippe Y (2000) Angola central area and SW corner: tertiary regional structural synthesis. Internal report. Elf Exploration [Internal Report]Google Scholar
  77. Pilcher R, Argent J (2007) Mega-pockmarks and linear pockmark trains on the West African continental margin. Mar Geol 244:15–32CrossRefGoogle Scholar
  78. Plaza-Faverola A, Bünz S, Mienert J (2011) Repeated fluid expulsion through sub-seabed chimneys offshore Norway in response to glacial cycles. Earth Planet Sci Lett 305:297–308CrossRefGoogle Scholar
  79. Pozrikidis C (1994) Shear flow over a plane wall with an axisymmetric cavity or a circular orifice of finite thickness. Phys Fluids 6:68–79Google Scholar
  80. Sahling H, Bohrmann G, Spiess V, Bialas J, Breitzke M, Ivanov M, Kasten S, Krastel S, Schneider R (2008) Pockmarks in the Northern Congo Fan area, SW Africa: Complex seafloor features shaped by fluid flow. Mar Geol 249:206–225CrossRefGoogle Scholar
  81. Sangree J, Widmier J (1978) Seismic stratigraphy and global changes of sea level, part 9: seismic interpretation of clastic depositional facies. Am Asso Petrol Geol Bull 62:752–771Google Scholar
  82. Sangree JB, Waylett DC, Frazier DE, Amery GB, Fennessy WJ (1978) Recognition of continental slope facies, offshore Texas-Louisiana. In: Bouma AH, Moore GT, Coleman JM (eds) Framework, facies and oil-trapping characteristics of the upper continental margin. Studies in geology, vol 7. American Association of Petroleum Geologists, Tulsa, pp 87–116Google Scholar
  83. Séranne M, Abeigne CRN (1999) Oligocene to Holocene sediment drifts and bottom currents on the slope of Gabon continental margin (West Africa): consequences for sedimentation and southeast Atlantic upwelling. Sediment Geol 128:179–199CrossRefGoogle Scholar
  84. Séranne M, Anka Z (2005) South Atlantic continental margins of Africa: a comparison of the tectonic vs climate interplay on the evolution of equatorial West Africa and SW Africa margins. J Afr Earth Sc 43:283–300CrossRefGoogle Scholar
  85. Sheriff RE (1978) A first course in geophysical exploration and interpretation. International Human Resources Development Corporation, Boston, p 313Google Scholar
  86. Sinha SN, Gupta AK, Oberai M (1982) Laminar separating flow over backsteps and cavities. II-Cavities. AIAA J 20:370–375CrossRefGoogle Scholar
  87. Sultan N, Cochonat P, Foucher JP, Mienert J (2004) Effect of gas hydrates melting on seafloor slope instability. Mar Geol 213:379–401CrossRefGoogle Scholar
  88. Taneda S (1979) Visualization of separating Stokes flows. J Phys Soc Jpn 46:1935–1942CrossRefGoogle Scholar
  89. Thomas S, Hill AJ, Clare MA, Shreeve JW, Unterseh S (2011) Understanding engineering challenges posed by natural hydrocarbon infiltration and the development of authigenic carbonate. In: 2011 Offshore technology conference, pp 1–15Google Scholar
  90. van Bennekom A, Berger G (1984) Hydrography and silica budget of the Angola Basin. Neth J Sea Res 17:149–200CrossRefGoogle Scholar
  91. Vangriesheim A, Khripounoff A, Crassous P (2009a) Turbidity events observed in situ along the Congo submarine channel. Deep Sea Res II 56:2208–2222CrossRefGoogle Scholar
  92. Vangriesheim A, Pierre C, Aminot A, Metzl N, Baurand F, Caprais J-C (2009b) The influence of Congo River discharges in the surface and deep layers of the Gulf of Guinea. Deep Sea Res II 56:2183–2196CrossRefGoogle Scholar
  93. Vignau S, Deharbe JM, Ros JB, Boutet C, Masse P, Jaffuel F, Walgenwitz F, Gerard J, Martin R, Blake B (2000) Well study report: sedimentology—inorganic geochemistry—structural analysis—biostratigraphy. Total SA [Internal Report]Google Scholar
  94. Yager PL, Nowell AR, Jumars PA (1993) Enhanced deposition to pits: a local food source for benthos. J Mar Res 51:209–236CrossRefGoogle Scholar
  95. Zdanski P, Ortega M, Fico NG Jr (2003) Numerical study of the flow over shallow cavities. Comput Fluids 32:953–974CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of GeosciencesNational Taiwan UniversityTaipeiTaiwan
  2. 2.Total-CSTJFPauFrance
  3. 3.Center for GeobiologyUniversity of BergenBergenNorway
  4. 4.Geological InstituteUniversity of BaselBaselSwitzerland
  5. 5.Unit of Earth SciencesUniversity of FribourgFribourgSwitzerland
  6. 6.Companie Genéral GéophysiqueLlandudnoUK

Personalised recommendations