Lessons Learned from Electron Microscopy of Deformed Opalinus Clay

  • Ben LaurichEmail author
  • Janos L. Urai
  • Guillaume Desbois
  • Jop Klaver
  • Christian Vollmer
  • Christophe Nussbaum
Conference paper
Part of the Springer Series in Geomechanics and Geoengineering book series (SSGG)


Using a combined approach of ion-beam milling and electron microscopy, we observe, describe and quantify the microstructure of naturally and synthetically deformed Opalinus Clay (OPA) and deduce its microstructural evolution and underlying deformation mechanisms. The investigated samples derive from the so-called Main Fault, a 10 m offset fold-bend thrust fault crossing the Mont Terri Rock Laboratory in the Swiss Jura Mountains. The samples are slightly overconsolidated, experienced a burial depth of 1350 m and a maximum temperature of 55 °C. Most impact on strain is attributed to frictional sliding and rigid body rotation. However, trans-granular fracturing, dissolution-precipitation of calcite, clay particle neoformation and grain deformation by intracrystalline plasticity have a significant contribution to the fabric evolution. The long-term in-situ deformation behavior of OPA is inferred to be more viscous than measured at laboratory conditions.


Shear Zone Clay Particle Accretionary Prism Rigid Body Rotation Rock Laboratory 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Amann F, Vogelhuber M (2015) Expert Report - Assessment of Geomechanical Properties of Intact Opalinus ClayGoogle Scholar
  2. Clauer N, Techer I, Nussbaum C, Laurich B (accepted) Geochemical signatures of paleofluids in calcite from microstructures and matrix of the main fault in the opalinus clay: a contribution to the regional evolutionary model. Swiss J GeosciGoogle Scholar
  3. Hobbs B, Means W, Williams P (1976) An outline of structural geology. Wiley, New YorkGoogle Scholar
  4. Houben ME, Desbois G, Urai JL (2013) Pore morphology and distribution in the shaly facies of opalinus clay (Mont Terri, Switzerland): insights from representative 2D BIB–SEM investigations on mm to nm scale. Appl Clay Sci 71:82–97. doi: 10.1016/j.clay.2012.11.006 CrossRefGoogle Scholar
  5. Klaver J, Desbois G, Urai JL, Littke R (2012) BIB-SEM study of the pore space morphology in early mature posidonia shale from the hills area. Germany Int J Coal Geol 103:12–25. doi: 10.1016/j.coal.2012.06.012 CrossRefGoogle Scholar
  6. Laurich B (2015) Evolution of microstructure and porosity in faulted Opalinus Clay. RWTH-AachenGoogle Scholar
  7. Laurich B, Urai JL, Desbois G, Vollmer C, Nussbaum C (2014) Microstructural evolution of an incipient fault zone in opalinus clay: insights from an optical and electron microscopic study of ion-beam polished samples from the main fault in the mt-terri underground research laboratory. J Struct Geol 67:107–128. doi: 10.1016/j.jsg.2014.07.014 CrossRefGoogle Scholar
  8. Laurich B, Urai JL, Nussbaum C (2016) Microstructures and deformation mechanisms in opalinus clay: insights from scaly clay from the Main Fault in the Mont Terri Rock Laboratory (CH). Solid Earth Discuss, 1–30. doi: 10.5194/se-2016-94
  9. Mazurek M, Hurford AJ, Leu W (2006) Unravelling the multi-stage burial history of the Swiss Molasse Basin: integration of apatite fission track, vitrinite reflectance and biomarker isomerisation analysis. Basin Res 18:27–50. doi: 10.1111/j.1365-2117.2006.00286.x CrossRefGoogle Scholar
  10. Niemeijer A, Marone C, Elsworth D (2008) Healing of simulated fault gouges aided by pressure solution: results from rock analogue experiments. J Geophys Res 113:B04204. doi: 10.1029/2007JB005376 CrossRefGoogle Scholar
  11. Nussbaum C, Kloppenburg A, Caer T, Bossart P (accepted) Tectonic evolution of the Mont Terri region, northwestern Swiss Jura: constraints from kinematic forward modelling. Swiss J GeosciGoogle Scholar
  12. Rutter EH, Holdsworth RE, Knipe RJ (2001) The nature and tectonic significance of fault-zone weakening: an introduction. Geological Society, London, Special Publications, vol. 186, pp. 1–11. doi: 10.1144/GSL.SP.2001.186.01.01
  13. Warr LN, Wojatschke J, Carpenter BM, Marone C, Schleicher AM, van der Pluijm BA (2014) A “slice-and-view” (FIB–SEM) study of clay gouge from the SAFOD creeping section of the San Andreas fault at ∼2.7 km depth. J Struct Geol 69:234–244. doi: 10.1016/j.jsg.2014.10.006 CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • Ben Laurich
    • 1
    Email author
  • Janos L. Urai
    • 1
    • 2
  • Guillaume Desbois
    • 2
  • Jop Klaver
    • 2
  • Christian Vollmer
    • 3
  • Christophe Nussbaum
    • 4
  1. 1.Federal Institute for Geosciences and Natural Resources (BGR)HannoverGermany
  2. 2.Structural Geology, Tectonics and GeomechanicsRWTH Aachen UniversityAachenGermany
  3. 3.Institute for MineralogyUniversity MünsterMünsterGermany
  4. 4.Swiss Geological Survey, Federal Office of Topography SwisstopoWabernSwitzerland

Personalised recommendations