Automated Subsampling of Geological Maps: A step towards 3D Geological Multiscale Modelling

Ranee E. Joshi and Mark Jessell and Mark Lindsay. ( 2020 )
in: 2020 RING Meeting, ASGA

Abstract

Three-dimensional (3D) modelling is a powerful tool that allows better visualization, understanding and communication of geology. It is common to produce singular static models created with geological data upscaled and/or downscaled to a predetermined scale appropriate to answer specific geological questions. However, this limits the meaningful geological information provided and increases the inherent risk involved in relying on the model to make informed geological assessments. This suggests 3D geological modelling is going towards producing dynamic geological models that allows data to be subsampled and dynamically visualized at a scale optimal to better answer specific geological questions. \\ This contribution presents the initial findings of subsampling 500K data-rich geological data and their resulting multiscale models. The geological data, both geological maps and structural measurements, are from the recent regional geologic mapping of the Murchison Domain by the Geological Survey of Western Australia (GSWA). The case study for this work is in the Yalgoo-Singleton Greenstone Belt. It is a mineralized, lithologically diverse and structurally complex area with regions of sparse and biased sampling, located in the Murchison Domain, western Youanmi Terrane, Yilgarn Craton. The multiscale models are built through systematically subsampling the geological maps (ESRI shapefile ‘.shp' format), ensuring 3D sample representativity and preserving its heterogeneity. As a proof of concept, the geological maps are subsampled based on stratigraphy hierarchy. The polygonal features are upscaled by simplifying the geometry and considering crucial vertices critical to preserving the shape and topology. The structural measurements are subsampled depending on the scale of interest. The subsampled data is used as inputs into geological modeling applications. The resulting models are used to describe the implications and constraints of the subsampled input to the output. \\ Multiscale subsampling demonstrates direct effects on how we visualize geology and provides a new approach to refining geological understanding of a region. In the Yalgoo-Singleton greenstone belt area, it has given a better understanding of stratigraphy, geometric constraints of the geological units, basin formation, history and tectonics.

Download / Links

    BibTeX Reference

    @INPROCEEDINGS{Joshi_RM2020,
        author = { Joshi, Ranee E. and Jessell, Mark and Lindsay, Mark },
         title = { Automated Subsampling of Geological Maps: A step towards 3D Geological Multiscale Modelling },
     booktitle = { 2020 RING Meeting },
          year = { 2020 },
     publisher = { ASGA },
      abstract = { Three-dimensional (3D) modelling is a powerful tool that allows better visualization, understanding and communication of geology. It is common to produce singular static models created with geological data upscaled and/or downscaled to a predetermined scale appropriate to answer specific geological questions. However, this limits the meaningful geological information provided and increases the inherent risk involved in relying on the model to make informed geological assessments. This suggests 3D geological modelling is going towards producing dynamic geological models that allows data to be subsampled and dynamically visualized at a scale optimal to better answer specific geological questions.  \\ This contribution presents the initial findings of subsampling 500K data-rich geological data and their resulting multiscale models. The geological data, both geological maps and structural measurements, are from the recent regional geologic mapping of the Murchison Domain by the Geological Survey of Western Australia (GSWA). The case study for this work is in the Yalgoo-Singleton Greenstone Belt. It is a mineralized, lithologically diverse and structurally complex area with regions of sparse and biased sampling, located in the Murchison Domain, western Youanmi Terrane, Yilgarn Craton. The multiscale models are built through systematically subsampling the geological maps (ESRI shapefile ‘.shp' format), ensuring 3D sample representativity and preserving its heterogeneity. As a proof of concept, the geological maps are subsampled based on stratigraphy hierarchy. The polygonal features are upscaled by simplifying the geometry and considering crucial vertices critical to preserving the shape and topology. The structural measurements are subsampled depending on the scale of interest. The subsampled data is used as inputs into geological modeling applications. The resulting models are used to describe the implications and constraints of the subsampled input to the output.  \\  Multiscale subsampling demonstrates direct effects on how we visualize geology and provides a new approach to refining geological understanding of a region. In the Yalgoo-Singleton greenstone belt area, it has given a better understanding of stratigraphy, geometric constraints of the geological units, basin formation, history and tectonics. }
    }