Skip to content

Leading Practice Mining Acts Review - Statutes Amendment Bill released | South Australia's Magnetite Strategy launched

Project name: Olympic Domain Airborne Electromagnetics
Project leader: Stephan Thiel
Project group: Tom Wise
Tim Munday (CSIRO)
Aaron Davies (CSIRO)
Program:Next Generation Copper Discovery Program

Synopsis

Map of South Australia showing location of the Olympic Domain Airborne Electromagnetics projectThe Gawler Craton in central South Australia is world renown as one of the country’s leading exploration destinations. With an area of approximately 440,000km2, the Gawler Craton is the oldest and largest geological province in South Australia and preserves a complex tectonic history that spans from c. 3200 Ma to 1450 Ma.

The Olympic Domain is a highly prospective area of the eastern Gawler Craton that has a proven history of hosting IOCG type deposits including the Olympic Dam IOCG-U deposit as well as Carrapateena, Khamsin, Fremantle Doctor, Red Lake, Punt Hill and Emmie Bluff. Its position along the eastern Gawler Craton is responsible for magmatic and fluid-focussing events during the Proterozoic, notably the ca 1590 Ma Hiltaba-related magmatism event.

Exploration in the Olympic Domain is however challenging, as extensive regolith and cover sequences obscure the basement geology. One way this challenge can be met is by continual advancements and innovations in the collection, integration and interpretation of geophysical datasets.

This new regional Airborne Electromagnetic (AEM) survey is part of a broader regional program that will attempt to define the distribution of cover sequences that obscure the basement geology and provide insight into the variation and characteristics of the overlaying sequences.

The data will be combined with magnetotelluric (MT) data collected as part of the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) as well as the Olympic Domain MT to help understand the relationships between deep crustal structures and the systems targeted by mineral explorers.

Background/Aims

Recent AusLAMP MT results across the Gawler Craton have revealed zones of enhanced crustal conductivity along the eastern margin of the craton along the Prominent Hill-Carrapateena-Punt Hill corridor. These zones coincide with the highly prospective Olympic Domain IOCG belt and may indicate a mantle plumbing system that lead to the formation of these mineral systems and deposits.

The Olympic Domain AEM survey is located on one such deep crustal conductive zone and is designed to investigate the possible upward continuation of the deep crustal anomaly through the cover sequence.

The survey will acquire approximately 5000 line kilometres of new AEM data over an area of 100 km x 100 km of the Olympic Domain. Lines will be collected by either a fixed- or rotary-wing platform at a line spacing of approximately 2 km line spacing.

The resultant AEM data will be combined with a complimentary broadband and audio magnetotelluric MT survey to provide scope for potential field modelling from the surface to depth. The resultant data and interpretations will help provide greater clarity on the depth to basement as well as inform researchers and explorers about aquifers in the cover.

This project is being undertaken in partnership with Geoscience Australia (a Division of the Commonwealth Department of Innovation and Science) under the National Collaboration Framework promoting State–Federal precompetitive geoscientific collaborative programs.

Key outcomes

  • New regional 1 km spaced airborne electromagnetic survey data over the prospective Olympic IOCG domain in the eastern Gawler Craton
  • A regional assessment of cover thickness, cover types and distribution of aquifers to better inform exploration strategies
  • Basement characterisation if penetration through cover is sufficiently achieved

Schedule for information and product delivery

DeliverableTimeframe
New regional 1 km spaced AEM survey and data available via SARIG Q1 2018
New cover thickness map, digital map download, SARIG Q2 2018
Report on survey results - MESA Journal article Q2 2018
Joint analysis with Olympic Domain Magnetotellurics (MT) survey for scale resolution to camp scale Q3 2018