Speaker: Heather Schijns, Global Principal Geophysicist, Seismic Geophysics, BHP
Title: 3D Seismic Feasibility Study of Olympic Dam
Date: Wed, May 10, 2023
Time: 4:30pm to 5:30pm PDT
Location: Room 111 – 409 Granville Street, Vancouver, BC, V6C 1T2
Olympic Dam is a world-class IOCG (iron-oxide copper gold) deposit located in Southern Australia, and is the flagship deposit for the IOCG deposit-style. It is one of the largest known copper deposits and single largest uranium deposit in the world. Mineralisation at Olympic Dam is disseminated in nature, and is hosted in hydrothermal breccia within Roxby Downs Granite. Between the gradational nature of the contacts between the iron-oxide rich breccia and the altered granite, and the small-scale heterogeneity of the breccia itself, few apparent opportunities exist to generate coherent seismic reflectivity. The feasibility of hard rock reflection seismic to effectively image IOCGs, and more broadly, deposits with disseminated mineralisation, has been unclear to date, with few examples in the literature. In 2021, BHP undertook an in depth 3D seismic feasibility study of Olympic Dam. Utilising a physical property model that included representative 3D geometry and geological variability, the feasibility study allowed detailed examination of the impact of various seismic acquisition and processing decisions on successfully imaging this complex geology. Here we present the feasibility study process and results.
Heather Schijns joined BHP in 2017 and works out of Vancouver, Canada as Global Principal Geoscientist, Seismic Geophysics. In this role Heather provides technical guidance and strategy for application of seismic methods and R&D across global copper, nickel, coal, iron ore and potash assets for purposes ranging from resource exploration/targeting to geotechnical characterisation.
Prior to joining BHP, Heather worked in exploration-focused roles at companies including MMG, Aurora Geosciences and TerraNotes using a broad range of geophysical methods. Work took her across 5 continents and offshore, including major projects in arctic Canada, Brazil and Tanzania. Heather is a graduate of the University of Alberta, where she completed an MSc and a PhD in geophysics with a focus on seismic rock physics of metamorphic rocks.