Towards stochastic modelling of folds in poly-deformed terranes using structural data

Lachlan Grose and Gautier Laurent and Laurent Ailleres and Mark Jessell and Guillaume Caumon. ( 2015 )
in: In Proc. of 17th IAMG Conference

Abstract

We present a data-driven parametric approach for modelling folds in poly-deformed terranes using an implicit scheme honouring structural geology concepts. Traditional implicit approaches involve interpolating between observations from orientation measurements and stratigraphic contacts. Our method allows for more structural elements (e.g. foliations, intersection lineations) and overprinting relationships to be incorporated into the modelling process. Each generation of folding is successively modelled, starting with the most recent folding event. At each stage, several scalar and vector fields are interpolated to represent the axial surfaces, the fold axis and vergence of each fold. The geometry of folds is defined by structural parameters, which are obtained using geostatistical processes for each fold generation. We also propose using this fold modelling method with a stochastic approach. Structural uncertainties are evaluated by varying data and parameters to generate a series of possible structural models. Variability between models is quantified using local statistical methods which highlight areas of the models which are most variable. A complex synthetic example of a fold interference pattern is used as a case study. A suite of possible models incorporating structural concepts are produced to sample the structural uncertainty. Uncertainties associated with older foliations are shown to have a higher impact on 3D model geometry variability and are more significant than uncertainties associated with the younger foliations. Our results suggest that uncertainty simulations looking into under-constrained region of poly-deformed terranes should aim to incorporate uncertainties associated with structural concepts building structurally consistent uncertainty models.

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    BibTeX Reference

    @INPROCEEDINGS{,
        author = { Grose, Lachlan and Laurent, Gautier and Ailleres, Laurent and Jessell, Mark and Caumon, Guillaume },
         title = { Towards stochastic modelling of folds in poly-deformed terranes using structural data },
     booktitle = { In Proc. of 17th IAMG Conference },
          year = { 2015 },
      abstract = { We present a data-driven parametric approach for modelling folds in poly-deformed terranes
    using an implicit scheme honouring structural geology concepts. Traditional implicit approaches
    involve interpolating between observations from orientation measurements and stratigraphic contacts.
    Our method allows for more structural elements (e.g. foliations, intersection lineations) and
    overprinting relationships to be incorporated into the modelling process. Each generation of folding
    is successively modelled, starting with the most recent folding event. At each stage, several
    scalar and vector fields are interpolated to represent the axial surfaces, the fold axis and vergence
    of each fold. The geometry of folds is defined by structural parameters, which are obtained using
    geostatistical processes for each fold generation. We also propose using this fold modelling method
    with a stochastic approach. Structural uncertainties are evaluated by varying data and parameters to
    generate a series of possible structural models. Variability between models is quantified using local
    statistical methods which highlight areas of the models which are most variable.
    
    A complex synthetic example of a fold interference pattern is used as a case study. A suite
    of possible models incorporating structural concepts are produced to sample the structural uncertainty.
    Uncertainties associated with older foliations are shown to have a higher impact on 3D model
    geometry variability and are more significant than uncertainties associated with the younger foliations.
    Our results suggest that uncertainty simulations looking into under-constrained region of
    poly-deformed terranes should aim to incorporate uncertainties associated with structural concepts
    building structurally consistent uncertainty models. }
    }