Skip to Main content Skip to Navigation
Theses

Géométrie des surfaces de faille et dépliage 3D : méthodes et applications

Abstract : Tesling the kinematic compatibilily of the geometry of a fault surface (1) and the geometry of the structure (2) which slips on the fault surface is a complex problem that we solved partially. We considered problem (1) in context of rigid blocks and problem (2) for a folded foliation. ln the general context of macro-model determination by inversion techniques, we propose a specific least-squares criterion to constrain the shape of faults so as to be compatible with the rigid block approximation, i.e., the two blocks remain in contact and slip on each other without strain. If this condition is met, the fault surface is a thread, i.e., a surface that is everywhere tangent to a non zero twistor vector field. Besides, we constrain the surface to be close to give points (well data or pickings on a depth-migrated seismic 3D cube), and to be smooth (principal curvature minimization). The rigid block criterion yields more plausible results than conventional approximation techniques based on second derivatives or curvature minimization, and it also predicts the direction of striae. We tested its effect on different natural examples (Cléry and San Cayetano faults). Restoration of a geological structure al earlier times is a good means to criticize. and next to improve its interpretation. We focused ourselves on the interbedding slip phenomenon, with bed-Iength aud volume conservation. We unfolded a (geometrical) foliation by optimizing following least-squares criteria : horizontalness, bed-length and volume conservation, under equality constraints related to the position of the "binding" or "pinsurface". We testedour formulation on different synthetic and experimental esxamples
Complete list of metadata

https://tel.archives-ouvertes.fr/tel-00745509
Contributor : Pascale Talour Connect in order to contact the contributor
Submitted on : Thursday, October 25, 2012 - 4:33:25 PM
Last modification on : Friday, September 30, 2022 - 4:08:34 AM
Long-term archiving on: : Saturday, December 17, 2016 - 4:50:19 AM

Identifiers

  • HAL Id : tel-00745509, version 1

Collections

Citation

Muriel Thibaut. Géométrie des surfaces de faille et dépliage 3D : méthodes et applications. Tectonique. Université Joseph-Fourier - Grenoble I, 1994. Français. ⟨tel-00745509⟩

Share

Metrics

Record views

240

Files downloads

76