1887
Volume 17, Issue 4
  • E-ISSN: 1365-2117

Abstract

ABSTRACT

A two‐dimensional, discrete‐element modelling technique is used to investigate the initiation and growth of detachment folds in sedimentary rocks above a weak décollement level. The model depicts the sedimentary rocks as an assemblage of spheres that obey Newton's equations of motion and that interact with elastic forces under the influence of gravity. Faulting or fracturing between neighbouring elements is represented by a transition from repulsive–attractive forces to solely repulsive forces. The sedimentary sequence is mechanically heterogeneous, consisting of intercalated layers of markedly different strengths and thicknesses. The interlayering of weak and strong layers within the sedimentary rocks promotes the localization of flexural flow deformation within the weak layers. Even with simple displacement boundary conditions, and straightforward interlayering of weak and strong layers, the structural geometries that develop are complex, with a combination of box, lift‐off and disharmonic detachment fold styles forming above the décollement. In detail, it is found that the modelled folds grow by both limb rotation and limb lengthening. The combination of these two mechanisms results in uplift patterns above the folds that are difficult, or misleading, to interpret in terms of simple kinematic models. Comparison of modelling results with natural examples and with kinematic models highlights the complexities of structural interpretation in such settings.

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2005-11-29
2020-04-10
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References

  1. Allen, M.P. & Tildesley, D.J. (1987) Computer Simulation of Liquids. Oxford Science Publications, Oxford.
    [Google Scholar]
  2. Allmendinger, R.W. (1998) Inverse and forward numerical modelling of trishear fault propagation folds. Tectonics, 17, 640–656.
    [Google Scholar]
  3. Anastasio, D.J., Fisher, D.M., Messina, T.A. & Holl, J.E. (1997) Kinematics of decollement folding in the Lost River Range, Idaho. J. Struct. Geol., 19, 355–368.
    [Google Scholar]
  4. Antonellini, M.A. & Pollard, D.D. (1995) Distinct element modelling of deformation bands in sandstone. J. Struct. Geol., 17, 1165–1182.
    [Google Scholar]
  5. Atkinson, P.A. & Wallace, W.K. (2003) Competent unit thickness in detachment folds in the Northeastern Brooks Range, Alaska: geometric analysis and a conceptual model. J. Struct. Geol., 25, 1751–1771.
    [Google Scholar]
  6. Bardet, J.P. & Proubet, J. (1992) The structure of shear bands in idealised granular materials. Appl. Mech. Rev., 45 (3), S118–S122.
    [Google Scholar]
  7. Bieniawski, Z.T. (1984) Rock Mechanics Design in Mining and Tunnelling. A.A. Balkema, The Netherlands, 272pp.
    [Google Scholar]
  8. Camborde, F., Mariotti, C. & Donzé, F.V. (2000) Numerical study of rock and concrete behaviour by discrete element modelling. Computers Geotech., 27, 225–247.
    [Google Scholar]
  9. Castelltort, S., Pochat, S. & Van den Driessche, J. (2004) How reliable are growth strata in interpreting short‐term (10 s to 100 s ka) growth structure kinematics?C. R. Geosci., 336, 151–158.
    [Google Scholar]
  10. Cundall, P.A. (1971) Distinct Element Models of rock and soil structure. In: Analytical and Computational Methods in Engineering Rock Mechanics (Ed. by E.T.Brown , pp. 129–163. Unwin Publishers, London.
    [Google Scholar]
  11. Cundall, P.A. & Strack, O.D.L. (1979) A discrete numerical model for granular assemblies. Geotechnique, 29 (1), 47–65.
    [Google Scholar]
  12. Donzé, F., Magnier, S.‐A. & Bouchez, J. (1996) Numerical modelling of a highly explosive source in an elastic‐brittle rock mass. J. Geophys. Res., 101 (2), 3103–3112.
    [Google Scholar]
  13. Donzé, F., Mora, P. & Magnier, S.‐A. (1994) Numerical simulation of faults and shear zones. Geophys. J. Int., 116, 46–52.
    [Google Scholar]
  14. Epard, J‐L. & Groshong, R.H. (1995) Kinematic models of detachment folding including limb rotation, fixed hinges, and layer‐parallel shortening. J. Struct. Geol., 247, 85–103.
    [Google Scholar]
  15. Finch, E., Hardy, S. & Gawthorpe, R.L. (2003) Discrete element modelling of contractional fault‐propagation folding above rigid basement blocks. J. Struct. Geol., 25, 515–528.
    [Google Scholar]
  16. Finch, E., Hardy, S. & Gawthorpe, R.L. (2004) Discrete element modelling of extensional fault‐propagation folding above rigid basement blocks. Basin Res., 16 (4), 467–488.
    [Google Scholar]
  17. Gould, H. & Tobochnik, J. (1988) Computer Simulation Methods Part I. Addison Wesley, Reading, MA.
    [Google Scholar]
  18. Grando, G. & McClay, K.R. (2004) Structural evolution of the Frampton growth fold system, Atwater valley‐Southern Green Canyon area, deep water Gulf of Mexico. Marine Petrol. Geol., 21 (7), 889–910.
    [Google Scholar]
  19. Hardy, S. & Poblet, J. (1994) Geometric and numerical model of progressive limb rotation in detachment folds. Geology, 22, 371–374.
    [Google Scholar]
  20. Heim, A. (1921) Geoligie der Schweitz. Leipsig. C.H. Tranchnitz, 704pp.
    [Google Scholar]
  21. Homza, T.X. & Wallace, W.K. (1995) Geometric and kinematic models for detachment folds with fixed and variable detachment depths. J. Struct. Geol., 17, 475–488.
    [Google Scholar]
  22. Homza, T.X. & Wallace, W.K. (1997) Detachment folds with fixed hinges and variable detachment depth, Northeastern Brooks Range. J. Struct. Geol., 19, 337–354.
    [Google Scholar]
  23. Iwashita, K. & Oda, M. (2000) Micro‐deformation mechanism of shear banding process based on modified distinct element method. Powder Technol., 109, 192–205.
    [Google Scholar]
  24. Jamison, W.R. (1987) Geometric analysis of fold development in overthrust terranes. J. Struct. Geol., 9, 207–219.
    [Google Scholar]
  25. Johnson, K.M. & Johnson, A.M. (2002a) Mechanical models of trishear‐like folds. J. Struct. Geol., 24, 277–287.
    [Google Scholar]
  26. Johnson, K.M. & Johnson, A.M. (2002b) Mechanical analysis of the geometry of forced‐folds. J. Struct. Geol., 24, 401–410.
    [Google Scholar]
  27. Kuhn, M.R. (1999) Structured deformation in granular materials. Mech. Mater., 31, 407–429.
    [Google Scholar]
  28. Mitra, S. (2003) A unified kinematic model for the evolution of detachment folds. J. Struct. Geol., 25, 1659–1673.
    [Google Scholar]
  29. Mora, P. & Place, D. (1993) A lattice solid model for the non‐linear dynamics of earthquakes. Int. J. Mod. Phys. C, 4 (6), 1059–1074.
    [Google Scholar]
  30. Mora, P. & Place, D. (1994) Simulation of the frictional stick‐slip instability. Pure Appl. Geophys., 143 (1–3), 61–87.
    [Google Scholar]
  31. Niño, F., Philip, H. & Chery, J. (1998) The role of bed‐parallel slip in the formation of blind thrust faults. J. Struct. Geol., 20, 503–516.
    [Google Scholar]
  32. Place, D., Lombard, F., Mora, P. & Abe, S. (2002) Simulation of the micro‐physics of rocks using LSMEarth. Pure Appl. Geophys., 159, 1911–1932.
    [Google Scholar]
  33. Place, D. & Mora, P. (2001) A random lattice solid model for simulation of fault zone dynamics and fracture processes. In: Bifurcation and Localisation Theory for Soils and Rocks, Vol. 99 (Ed. by H.‐B.Mulhaus , A.V.Dyskin & E.Pasternak ) A.A. Balkema, Rotterdam/Brookfield.
    [Google Scholar]
  34. Poblet, J. & Hardy, S. (1995) Reverse modelling of detachment folds: application to the Pico del Aguila anticline in the South Central Pyrenees (Spain). J. Struct. Geol., 17, 1707–1724.
    [Google Scholar]
  35. Poblet, J. & McClay, K.R. (1996) Geometry and kinematics of single‐layer detachment folds. Am. Assoc. Petrol. Geol. Bull., 80, 1085–1109.
    [Google Scholar]
  36. Rockwell, T.K., Keller, E.A. & Dembroff, G.R. (1988) Quaternary rate of folding of the Ventura Avenue anticline, Western Transverse Ranges, southern California. Geol. Soc. Am. Bull., 100, 850–858.
    [Google Scholar]
  37. Poblet, J., Muñoz, J.A., Travé, A. & Serra‐Kiel, J. (1998) Quantifying the kinematics of detachment folds using the 3D geometry: application to the Mediano anticline (Pyrenees, Spain). Geol. Soc. Am. Bull., 110, 111–125.
    [Google Scholar]
  38. Saltzer, S.D. & Pollard, D.D. (1992) Distinct element modeling of structures formed in sedimentary overburden by extensional reactivation of basement normal faults. Tectonics, 11, 165–174.
    [Google Scholar]
  39. Scharer, K.M., Burbank, D.W., Chen, J., Weldon, R.J., Rubin, C., Zhao, R. & Shen, J. (2004) Detachment folding in the Southwestern Tian Shan‐Tarim foreland, China: shortening estimates and rates. J. Struct. Geol., 26, 2119–2137.
    [Google Scholar]
  40. Scott, D.R. (1996) Seismicity and stress rotation in a granular model of the brittle crust. Nature, 381 (6583), 592–595.
    [Google Scholar]
  41. Shaw, J.H., Novoa, E. & Connors, C.D. (2004) Structural controls on growth stratigraphy in contractional fault‐related folds. In: Thrust Tectonics and Hydrocarbon Systems (Ed. by K.R.McClay ), AAPG Mem., 82, 400–412.
    [Google Scholar]
  42. Strayer, L.M., Erickson, S.G. & Suppe, J. (2004) Influence of growth strata on the evolution of fault‐related folds‐distinct element models. In: Thrust Tectonics and Hydrocarbon Systems (Ed. by K.R.McClay ), AAPG Mem., 82, 413–437.
    [Google Scholar]
  43. Strayer, L.M. & Huddleston, P.J. (1997) Numerical modelling of fold initiation at thrust ramps. J. Struct. Geol., 19, 551–566.
    [Google Scholar]
  44. Strayer, L.M. & Suppe, J. (2002) Out‐of‐plane motion of a thrust sheet during along‐strike propagation of a thrust ramp: a distinct element approach. J. Struct. Geol., 24, 637–650.
    [Google Scholar]
  45. Toomey, A. & Bean, C.J. (2000) Numerical simulation of seismic waves using a discrete particle scheme. Geophys. J. Int., 141, 595–604.
    [Google Scholar]
  46. Wallace, W.K. & Homza, T.X. (2004) Detachment folds versus fault‐propagation folds, and their truncation by thrust faults. In: Thrust Tectonics and Hydrocarbon Systems (Ed. by K.R.McClay ), AAPG Mem., 82, 324–355.
    [Google Scholar]
  47. Wilkerson, M.S., Medwedeff, D.A. & Marshak, S. (1991) Geometrical modeling of fault‐related folds: a pseudo-three-dimensional approach. J. Struct. Geol., 13, 801–812.
    [Google Scholar]
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