Grose, Lachlan1, Ailleres, Laurent1, Laurent, Gautier2, Jessell, Mark3
1School of Earth Atmosphere and Environment, Monash University, Melbourne 3800, Australia, 2 Université d’Orléans, CNRS, BRGM, ISTO, UMR 7327, Orleans France, 3 Mineral Exploration Cooperative Research Centre, School of Earth Sciences, UWA, Perth, Australia
LoopStructural is a new open source 3D geological modelling python package (www.github.com/Loop3d/LoopStructural). Geological features are encoded into the geological model using a time aware approach where the relative timing of different deformation features is used to help construct complicated geometries. We use structural frames which are curvilinear coordinate systems based around the major structural feature (e.g. fold axial surfaces, fault surfaces), structural direction (e.g. fold axis, fault slip direction) and where necessary an intermediate direction (e.g. fault extent). This allows for folds and faults to be integrated into the description of the geological features in the implicit models. In this contribution we will use map2loop to automatically extract and augment input data from open access geological datasets from Geological Survey of Western Australia from the Hamersley Basin. The model area will include consists of upright refolded folds of Archean and Proterozoic stratigraphy overlying an Archean basement. The folded stratigraphy is overprinted by NW-SE trending faults. In the model the fault network is modelled first using observations of the fault trace using the estimated displacements from the geological map. The folded stratigraphy is then modelled by building a fold frame that characterises the geometry of the axial surface and the fold axis direction. The fold geometry is modelled by fitting curves representing the fold axis geometry in the axial surface and the fold geometry looking down plunge. We show that by using the fold constraints the geometry of the modelled folds are consistent with the geometries drawn in cross sections.
Lachlan is a research fellow at Monash University working on the Loop project. His research interests are encoding structural geology in 3D geological modelling algorithms.