Journal metrics

Journal metrics

  • IF value: 4.165 IF 4.165
  • IF 5-year value: 4.075 IF 5-year 4.075
  • CiteScore value: 4.28 CiteScore 4.28
  • SNIP value: 1.501 SNIP 1.501
  • SJR value: 1.060 SJR 1.060
  • IPP value: 4.21 IPP 4.21
  • h5-index value: 29 h5-index 29
  • Scimago H index value: 27 Scimago H index 27
Volume 7, issue 3
Solid Earth, 7, 843-856, 2016
https://doi.org/10.5194/se-7-843-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Solid Earth, 7, 843-856, 2016
https://doi.org/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

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 Michael Kettermann et al.
  • 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.

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...
Citation
Share