Journal cover Journal topic
Solid Earth An interactive open-access journal of the European Geosciences Union

Journal metrics

  • IF value: 2.083 IF 2.083
  • IF 5-year<br/> value: 2.138 IF 5-year
    2.138
  • CiteScore<br/> value: 2.14 CiteScore
    2.14
  • SNIP value: 0.783 SNIP 0.783
  • SJR value: 1.039 SJR 1.039
  • IPP value: 1.987 IPP 1.987
  • h5-index value: 20 h5-index 20
Solid Earth, 7, 843-856, 2016
http://www.solid-earth.net/7/843/2016/
doi:10.5194/se-7-843-2016
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
27 May 2016
Dilatant normal faulting in jointed cohesive rocks: a physical model study
Michael Kettermann1, Christoph von Hagke1, Heijn W. van Gent1,a, Christoph Grützner2,b, and Janos L. Urai1 1Structural Geology, Tectonics and Geomechanics Energy and Mineral Resources Group, RWTH Aachen University, Lochnerstraße 4-20, 52056 Aachen, Germany
2Neotectonics and Natural Hazards, RWTH Aachen University, Lochnerstraße 4-20, 52056 Aachen, Germany
anow at: Shell International Exploration and Production Company, The Hague, the Netherlands
bnow at: COMET; Bullard Laboratories, Department of Earth Sciences, University of Cambridge, Cambridge, UK
Abstract. Dilatant faults often form in rocks containing pre-existing joints, but the effects of joints on fault segment linkage and fracture connectivity are not well understood. We present an analogue modeling study using cohesive powder with pre-formed joint sets in the upper layer, varying the angle between joints and a rigid basement fault. We analyze interpreted map-view photographs at maximum displacement for damage zone width, number of connected joints, number of secondary fractures, degree of segmentation and area fraction of massively dilatant fractures. Particle imaging velocimetry provides insight into the deformation history of the experiments and illustrates the localization pattern of fault segments. Results show that with increasing angle between joint-set and basement-fault strike the number of secondary fractures and the number of connected joints increase, while the area fraction of massively dilatant fractures shows only a minor increase. Models without pre-existing joints show far lower area fractions of massively dilatant fractures while forming distinctly more secondary fractures.

Citation: Kettermann, M., von Hagke, C., van Gent, H. W., Grützner, C., and Urai, J. L.: Dilatant normal faulting in jointed cohesive rocks: a physical model study, Solid Earth, 7, 843-856, doi:10.5194/se-7-843-2016, 2016.
Publications Copernicus
Download
Short summary
We present an analogue modeling study on the interaction of pre-existing joints and normal faults using cohesive powder. We vary the angle between joints and a rigid basement fault and analyze interpreted map-view photographs at maximum displacement for various parameters and compare to nature. Results show a clear effect of increasing angle between joints and faults on fault geometry, fracture density and connectivity. These information can help interpreting fractured layers in the subsurface.
We present an analogue modeling study on the interaction of pre-existing joints and normal...
Share