The geochemical footprint of the Bulldog Shale, Eromanga Basin, Australia

Eline Baudet1, Caroline Forbes1, David Giles2, Steve Hill3 1. DET CRC; School of Earth Sciences, University of Adelaide 2. DET CRC; Future Industries Institute, UniSa 3. Geological Survey of South Australia

GSSA Discovery Day, Adelaide, South Australia 1 December 2016

World metal demand The study area

Modified from Geoscience Australia The aim

To understand the processes responsible for variable geochemical and mineralogical signatures within the Bulldog Shale and how they relate to buried mineralisations The study area

Bulldog Shale

Cadna-owie Formation Background chemistry

Maximum background Mo Zn Cu values in ppm Bulldog Shale 10 250 50 Cadna-Owie No Mo 280 28 Formation Oodnadatta 10 200 35 Formation

Vertical geochemical variations EARLY CRETACEOUS EARLY Lateral geochemical variations Bulldog Shale Cadna-Owie Oodnadatta Chemical variations Mineralogical control? • Depth? Structural control? • Different recharge zones? • Variations within paleo- environment? • Different underlying basements (as shown on map) and basins?

Modified from Radke et al., 2000

Modified from Geoscience Australia,Source: 2002 SARIG Conclusions • Anomalous metal content recognised in the sedimentary formations studied

• Elements dispersed from both aquifers (the Cadna-owie Formation and the Coorikiana Sandstone) into the Oodnadatta Formation and the Bulldog Shale

• The formations studied preserve interesting geochemically variations

• Future work: • integrate HyLogger data with geochemistry  dispersion processes • Integrated groundwater study  chemical relationships to geology • Small scale study over Prominent Hill  signatures over known mineralisation Thank you for your attention

Acknowledgements Special acknowledgements to Georgina Gordon, Alan Mauger, Aaron Baensch, Nathan Reid and David Gray for assisting me with the data collection, processing and interpretation

The work has been supported by the Deep Exploration Technologies CRC whose activities are funded by the Australian Government's CRC Programme.

This is DET CRC Presentation 2016/898