1887
Volume 25, Issue 1
  • ISSN: 1354-0793
  • E-ISSN:

Abstract

Salt welds form due to salt thinning by mechanical (e.g. salt-flow) and/or chemical (e.g. salt-dissolution) processes. Despite being ubiquitous in salt-bearing sedimentary basins, where they may trap large volumes of hydrocarbons, little is published on weld thickness and composition. We here use 3D seismic reflection, borehole and biostratigraphic data from the Atwater Valley protraction area of the northern Gulf of Mexico to constrain the thickness and composition of a salt weld. Seismic data image an ‘apparent weld’ at the base of a Plio-Pleistocene minibasin that subsided into allochthonous salt. Borehole data indicate the weld is actually ‘incomplete’, being 24 m thick, and containing an upper 5 m-thick halite and a lower 15 m-thick halite, separated by a 4 m-thick mudstone. The age and origin of the intra-weld mudstone is unclear, although we speculate it is either: (i) Late Jurassic, representing material transported upwards from the autochthonous level within a feeder, and subsequently trapped as allochthonous salt thinned and welded; or, perhaps, more likely (ii) Pliocene, representing a piece of salt carapace reworked from the top of and eventually trapped in the now locally welded sheet. We show that 3D seismic reflection data may not resolve weld thickness, with the presence of relatively thin remnant salt lending support to models of welding based on viscous flow. The halite-dominated character of the weld also supports the hypothesis that tectonic purification may occur during salt flow.

uninterpreted seismic reflection profiles, raw biostratigraphic data and a BOEM biostratigraphic chart are available at https://doi.org/10.6084/m9.figshare.c.4183061

Loading

Article metrics loading...

/content/journals/10.1144/petgeo2018-008
2018-08-28
2024-04-24
Loading full text...

Full text loading...

References

  1. Chemia, Z., Koyi, H. & Schmeling, H.
    2008. Numerical modelling of rise and fall of a dense layer in salt diapirs. Geophysical Journal International, 172, 798–816.
    [Google Scholar]
  2. Cohen, H.A. & Hardy, S.
    1996. Numerical modelling of stratal architectures resulting from differential loading of a mobile substrate. In: Alsop, G.I., Blundell, D.J. & Davison, I. (eds) Salt Tectonics. Geological Society, London, Special Publications, 100, 265–273, https://doi.org/10.1144/GSL.SP.1996.100.01.17
    [Google Scholar]
  3. Dalgarno, C.R. & Johnson, J.E.
    1968. Diapiric structures and late Precambrian–Early Cambrian sedimentation in the Flinders Ranges, South Australia. In: Braunstein, J. & O'Brien, G.D. (eds) Diapirism and Diapirs: A Symposium. AAPG Memoirs, 8, 301–314.
    [Google Scholar]
  4. Diegel, F.A., Karlo, J.F., Schuster, D.C., Shoup, R.C. & Tauvers, P.R.
    1995. Cenozoic structural evolution and tectono-stratigraphic framework of the northern Gulf Coast continental margin. In: Jackson, M.P.A., Roberts, D.G. & Snelson, S. (eds) Salt Tectonics: A Global Perspective. AAPG Memoirs, 65, 109–151.
    [Google Scholar]
  5. Fiduk, J.C. & Rowan, M.G.
    2012. Analysis of folding and deformation within layered evaporites in Blocks BM-S-8 & -9, Santos Basin, Brazil. In: Alsop, G.I., Archer, S.G., Hartley, A.J., Grant, N.T. & Hodgkinson, R. (eds) Salt Tectonics, Sediments and Prospectivity. Geological Society, London, Special Publications, 363, 471–487, https://doi.org/10.1144/SP363.22
    [Google Scholar]
  6. Gansser, A.
    1992. The enigma of the Persian salt-dome inclusions. Eclogae Geologicae Helvetiae, 85, 825–846.
    [Google Scholar]
  7. Hazzard, R.T., Spooner, W.C. & Blanpied, B.W.
    1947. Notes on the stratigraphy of the formations which underlie the Smackover Limestone in south Arkansas, northeast Texas, and north Louisiana. In: Shreveport Geological Society Reference Report on Certain Oil and Gas Fields of North Louisiana, South Arkansas, Mississippi and Alabama, Volume II. Shreveport Geological Society, Shreveport, IL, USA, 483–503.
    [Google Scholar]
  8. Hilchie, D.W.
    1968. Caliper logging – theory and practice. The Log Analyst, 9, 3–12.
    [Google Scholar]
  9. Hoetz, G., Steenbrinkl, J., Bekkers, N., Vogelaar, A. & Luthi, S.
    2011. Salt-induced stress anomalies: an explanation for variations in seismic velocity and reservoir quality. Petroleum Geoscience, 17, 385–396, https://doi.org/10.1144/1354-079311-002
    [Google Scholar]
  10. Hudec, M.R. & Jackson, M.P.A.
    2007. Terra infirm: understanding salt tectonics. Earth-Science Reviews, 82, 1–28.
    [Google Scholar]
  11. 2011. The Salt Mine: A Digital Atlas of Salt Tectonics. AAPG Memoirs, 99.
    [Google Scholar]
  12. Hudec, M.R., Jackson, M.P.A. & Peel, F.J.
    2013a. Influence of deep Louann structure on the evolution of the northern Gulf of Mexico. AAPG Bulletin, 97, 1711–1735.
    [Google Scholar]
  13. Hudec, M.R., Norton, I.O., Jackson, M.P.A. & Peel, F.J.
    2013b. Jurassic evolution of the Gulf of Mexico salt basin. AAPG Bulletin, 97, 1683–1710.
    [Google Scholar]
  14. Humphris, C.C., Jr
    . 1978. Salt movement on continental slope, northern Gulf of Mexico. In: Bouma, A.H., Moore, G.T. & Coleman, J.M. (eds) Framework, Facies, and Oil-Trapping Characteristics of the Upper Continental Margin. AAPG Studies in Geology, 7, 69–86.
    [Google Scholar]
  15. Jackson, M.P.A. & Cramez, C.
    1989. Seismic recognition of salt welds in salt tectonic regimes. In: Gulf of Mexico Salt Tectonics: Associated Processes and Exploration Potential. Tenth Annual Research Conference Program and Extended and Illustrated Abstracts . GCSSEPM Foundation, Austin, TX, USA, 66–71.
    [Google Scholar]
  16. Jackson, M.P.A. & Hudec, M.R.
    2017. Salt Tectonics: Principles and Practice. Cambridge University Press, Cambridge.
    [Google Scholar]
  17. Jackson, C.A.-L., Rodriguez, C.R., Rotevatn, A. & Bell, R.E.
    2014. Geological and geophysical expression of a primary salt weld: An example from the Santos Basin, Brazil. Interpretation, 2, SM77–SM89.
    [Google Scholar]
  18. Jackson, C.A.-L., Jackson, M.P.A., Hudec, M.R. & Rodriguez, C.R.
    2015. Enigmatic structures within salt walls of the Santos Basin – Part 1: Geometry and kinematics from 3D seismic reflection and well data. Journal of Structural Geology, 75, 135–162.
    [Google Scholar]
  19. Kent, P.E.
    1979. The emergent Hormuz salt plugs of southern Iran. Journal of Petroleum Geology, 2, 117–144.
    [Google Scholar]
  20. Kneller, E.A. & Johnson, C.A.
    2011. Plate kinematics of the Gulf of Mexico based on integrated observations from the Central and South Atlantic. Gulf Coast Association of Geological Societies Transactions, 61, 283–300.
    [Google Scholar]
  21. Koyi, H.
    2001. Modeling the influence of sinking anhydrite blocks on salt diapirs targeted for hazardous waste disposal. Geology, 29, 387–390.
    [Google Scholar]
  22. Koyi, H. & Schott, B.
    2000. The rise and fall of denser blocks within salt diapirs. Bollettino di Geofisica teorica ed applicata, 42, 64–66.
    [Google Scholar]
  23. Kupfer, D.H.
    1968. Relationship of internal and external structure of salt domes. In: Braunstein, J. & O'Brien, G.D. (eds) Diapirism and Diapirs. AAPG Memoirs, 8, 79–89.
    [Google Scholar]
  24. Lawton, T.F. & Amato, J.M.
    2017. U–Pb ages of igneous xenoliths in a salt diapir, La Popa basin: Implications for salt age in onshore Mexico salt basins. Lithosphere, 9, 745–758.
    [Google Scholar]
  25. Liro, L. & Holdaway, S.M.
    2011. Salt welds in the deepwater Gulf of Mexico – Uncertainties in the amount of remnant salt: seismic and well examples. Paper presented at theAAPG Annual Convention And Exhibition on Making the Next Giant Leap in Geosciences, April 10–13, 2011, Houston, Texas, USA.
    [Google Scholar]
  26. Peel, F.J., Travis, C.J. & Hossack, J.R.
    1995. Genetic structural provinces and salt tectonics of the Cenozoic offshore U.S. Gulf of Mexico: A preliminary analysis. In: Jackson, M.P.A., Roberts, D.G. & Snelson, S. (eds) Salt Tectonics: A Global Perspective. AAPG Memoirs, 65, 153–175.
    [Google Scholar]
  27. Pilcher, R.S., Kilsdonk, B. & Trude, J.
    2011. Primary basins and their boundaries in the deep-water northern Gulf of Mexico: Origin, trap types, and petroleum system implications. AAPG Bulletin, 95, 219–240.
    [Google Scholar]
  28. Pindell, J. & Dewey, J.F.
    1982. Permo-Triassic reconstruction of western Pangea and the evolution of the Gulf of Mexico/Caribbean region. Tectonics, 1, 179–211.
    [Google Scholar]
  29. Richter-Bernburg, G.
    1980. Salt domes in northwest Germany. Bulletin des Centres de Recherches Exploration–Production, Elf Aquitaine, 4, 373–393.
    [Google Scholar]
  30. Rider, M. & Kennedy, M.
    2011. The Geological Interpretation of Well Logs. 3rd edn. Rider-French Consulting Ltd, Rogart, Sutherland, UK.
    [Google Scholar]
  31. Rowan, M.G.
    1995. Structural styles and evolution of allochthonous salt, central Louisiana outer shelf and upper slope. In: Jackson, M.P.A., Roberts, D.G. & Snelson, S. (eds) Salt Tectonics: A Global Perspective. AAPG Memoirs, 65, 199–228.
    [Google Scholar]
  32. 2004. Do salt welds seal?In: Post, P.J., Olson, D.L., Lyons, K.T., Palmes, S.L. Harrison, P.F. & Rosen, N.C. (eds) Salt–Sediment Interactions and Hydrocarbon Prospectivity: Concepts, Applications, and Case Studies for the 21st Century.Proceedings of the GCSSEPM Foundation 24th Annual Bob F. Perkins Research Conference. GCSSEPM Foundation, Austin, TX, USA, 390–403.
    [Google Scholar]
  33. Rowan, M.G., Lawton, T.F. & Giles, K.A.
    2012. Anatomy of an exposed vertical salt weld and flanking strata La Popa Basin, Mexico. In: Alsop, G.I., Archer, S.G., Hartley, A.J., Grant, N.T. & Hodgkinson, R. (eds) Salt Tectonics, Sediments and Prospectivity. Geological Society, London, Special Publications, 363, 33–57, https://doi.org/10.1144/SP363.3
    [Google Scholar]
  34. Salvador, A.
    1987. Late Triassic–Jurassic paleogeography and origin of Gulf of Mexico Basin. AAPG Bulletin, 71, 419–451.
    [Google Scholar]
  35. Strozyk, F., Van Gent, H., Urai, J.L. & Kukla, P.A.
    2012. 3D seismic study of complex intra-salt deformation: An example from the Upper Permian Zechstein 3 stringer, western Dutch offshore. In: Alsop, G.I., Archer, S.G., Hartley, A.J., Grant, N.T. & Hodgkinson, R. (eds) Salt Tectonics, Sediments and Prospectivity. Geological Society, London, Special Publications, 363, 489–501, https://doi.org/10.1144/SP363.23
    [Google Scholar]
  36. Theys, P.
    1999. Log Data Acquisition and Quality Controls. 2nd edn. Editions Technip, Paris.
    [Google Scholar]
  37. Van Gent, H., Urai, J.L. & de Keijzer, M.
    2011. The internal geometry of salt structures – a first look using 3D seismic data from the Zechstein of the Netherlands. Journal of Structural Geology, 33, 292–311.
    [Google Scholar]
  38. Wagner, B.H., III
    . 2010. An analysis of salt welding. PhD dissertation, University of Texas at Austin, Austin, TX, USA.
    [Google Scholar]
  39. Wagner, B.H., III & Jackson, M.P.A.
    2011. Viscous flow during salt welding. Tectonophysics, 510, 309–326.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1144/petgeo2018-008
Loading
/content/journals/10.1144/petgeo2018-008
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