Surface restoration as a means to characterize transverse fault slip uncertainty

in: Gocad Meeting, Association Scientifique pour la G{\'e}ologie et ses Applications (ASGA)

Abstract

Proper understanding and mapping of a geological domain calls for a good characterization of fault slip. Several fault displacements can be proposed to explain a given geometry of the three-dimensional geological model. Most approaches ignore this, and assume a fixed direction of fault slip, for instance along the main dipping line. Instead, we propose to generate several fault displacement models that all conform to available geometrical data and a given structural deformation style. The method uses sequential Monte-Carlo sampling to simulate fault displacement vectors on a geological horizon; balanced restoration is run to compute the likelihood of the fault net slip. Acceptable models are selected using the Metropolis-Hastings algorithm. This procedure allows selecting the best model of fault displacements given the retained structural style. Alternatively, the fault throw configurations obtained can be input in a global uncertainty assessment workflow. To assess the uncertainty of fault properties (e.g., shale-gouge ratio), and of stratigraphic transforms such as the geo-chronological parameterization. The sampling method is demonstrated on a complex, heavily-faulted stratigraphic model. A discussion on the principle of parsimony and deterministic versus stochastic modeling is included.

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BibTeX Reference

@inproceedings{caumon:hal-03169290,
 abstract = {Proper understanding and mapping of a geological domain calls for a good characterization of fault slip. Several fault displacements can be proposed to explain a given geometry of the three-dimensional geological model. Most approaches ignore this, and assume a fixed direction of fault slip, for instance along the main dipping line. Instead, we propose to generate several fault displacement models that all conform to available geometrical data and a given structural deformation style. The method uses sequential Monte-Carlo sampling to simulate fault displacement vectors on a geological horizon; balanced restoration is run to compute the likelihood of the fault net slip. Acceptable models are selected using the Metropolis-Hastings algorithm. This procedure allows selecting the best model of fault displacements given the retained structural style. Alternatively, the fault throw configurations obtained can be input in a global uncertainty assessment workflow. To assess the uncertainty of fault properties (e.g., shale-gouge ratio), and of stratigraphic transforms such as the geo-chronological parameterization. The sampling method is demonstrated on a complex, heavily-faulted stratigraphic model. A discussion on the principle of parsimony and deterministic versus stochastic modeling is included.},
 address = {Nancy, France},
 author = {Caumon, Guillaume and Muron, Pierre},
 booktitle = {{Gocad Meeting}},
 hal_id = {hal-03169290},
 hal_version = {v1},
 month = {June},
 pdf = {https://hal.univ-lorraine.fr/hal-03169290v1/file/CaumonMuron_uncert_restor.pdf},
 publisher = {{Association Scientifique pour la G{\'e}ologie et ses Applications (ASGA)}},
 title = {{Surface restoration as a means to characterize transverse fault slip uncertainty}},
 url = {https://hal.univ-lorraine.fr/hal-03169290},
 volume = {26},
 year = {2006}
}