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| Titel |
Structural and mechanical analysis of the Mont Terri Anticline (Jura, Switzerland) |
| VerfasserIn |
Typhaine Caër, Pauline Souloumiac, Bertrand Maillot, Pascale Leturmy, Christophe Nussbaum |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250090821
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| Publikation (Nr.) |
 EGU/EGU2014-5080.pdf |
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| Zusammenfassung |
| The main motivation of this study is to illustrate how geometrical constructions of geological
structures can be constrained by mechanical equilibrium and the Coulomb criterion using the
theory of limit analysis. In the NW deformation front of the Jura thrust belt in Switzerland,
the Mont-Terri anticline is located at an interruption of the Muschelkalk décollement, due to
former normal faults. It is characterised by a reversed frontal limb, a steep back limb, and a
ramp cross-cutting some of the former normal faults. A borehole and a highway tunnel
constrain the inner structure. Three 2D kinematics and present-day cross-sections are
proposed as various combinations of fault-bend folds, fault propagation folds and
detachment folds (one of them being the only previously published interpretation of
Mont Terri). Each interpretation is tentatively tested with the external approach of
limit analysis, leading to different compatible ranges of values of the frictional
parameters and of their variation with progressive shortening. It is not possible to
reject any interpretation with confidence. Furthermore, the exact evolution of the
topography during shortening is largely unknown. It is shown by the mechanical
analysis to play a very important role in selecting the locations and dips of the
active faults because it imposes spatial variations of their loading. The merit of the
present approach is therefore to provide a quantitative link between the assumed
evolution of the internal structure, the topography, and the frictional parameters. |
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