Integration of geoscientific uncertainty into geophysical inversion by means of local gradient regularization
J. Giraud,
M. Lindsay,
V. Ogarko,
M. Jessell,
R. Martin,
E. Pakyuz-Charrier
Affiliations
J. Giraud
Centre for Exploration Targeting, School of Earth Sciences, University of Western Australia, 35 Stirling Highway, WA Crawley 6009, Australia
M. Lindsay
Centre for Exploration Targeting, School of Earth Sciences, University of Western Australia, 35 Stirling Highway, WA Crawley 6009, Australia
V. Ogarko
The International Centre for Radio Astronomy Research, 7 Fairway, Ken and Julie Michael Building, The University of Western, Australia, WA Crawley 6009, Australia
M. Jessell
Centre for Exploration Targeting, School of Earth Sciences, University of Western Australia, 35 Stirling Highway, WA Crawley 6009, Australia
R. Martin
Géoscience Environnement Toulouse, UMR CNRS 5563, Université Paul Sabatier, Observatoire Midi-Pyrénées, 14 Avenue Edouard Belin, 31400 Toulouse, France
E. Pakyuz-Charrier
Centre for Exploration Targeting, School of Earth Sciences, University of Western Australia, 35 Stirling Highway, WA Crawley 6009, Australia
We introduce a workflow integrating geological modelling uncertainty information to constrain gravity inversions. We test and apply this approach to the Yerrida Basin (Western Australia), where we focus on prospective greenstone belts beneath sedimentary cover. Geological uncertainty information is extracted from the results of a probabilistic geological modelling process using geological field data and their inferred accuracy as inputs. The uncertainty information is utilized to locally adjust the weights of a minimum-structure gradient-based regularization function constraining geophysical inversion. Our results demonstrate that this technique allows geophysical inversion to update the model preferentially in geologically less certain areas. It also indicates that inverted models are consistent with both the probabilistic geological model and geophysical data of the area, reducing interpretation uncertainty. The interpretation of inverted models reveals that the recovered greenstone belts may be shallower and thinner than previously thought.
