Print this pageSCHAEFER, F.1, DZUBER, R.1, MURRAY, T.2, GRIFFITHS, P. A.2, and LEMON, N.3
1Midland Valley Exploration
Ltd, Hannover, Germany
2Midland Valley Exploration
Ltd, Glasgow, UK
3NCPGG, Adelaide, Australia
Abstract: 3D Restoration of the Oratunga Breccia Body, Flinders Range, South Australia: is it a Diapir?
The Oratunga Breccia Body of the Flinders Range, South Australia, has been subject to controversial discussion of its genetic origin, ranging from carbonatitic intrusions and deformed horst blocks to megaslumps and diapirism.
Three-dimensional restoration provides a powerful tool to validate structural interpretations and the geohistory of a given model. We use 3D restoration software to examine a syndepositional diapiric interpretation of the Oratunga structure. This interpretation is based on analogue diapir modelling results resembling the field structure around the Oratunga body.
Based on the assumption that salt flow at depth generates a response in the sedimentary overburden, the sequential restoration of overburden horizons will reproduce salt flow patterns and overburden basin geometry through time.
The 3D model is built from outcrop traces, dip data, and two structural cross sections through the Oratunga structure. We carry out a sequential restoration of key horizons surrounding the presumed diapir, reconstructing eroded strata where necessary. The proposed geohistory model of a diapiric rise triggered by an early inversion fault is tested and refined through the restoration results.
AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas