Palaeodrainage and Tertiary Coastal Barriers of South Australia

The current high level of exploration activity for uranium and heavy mineral sands associated with palaeodrainage and palaeocoastal sediments in South Australia, has driven demand for an early First Edition of a map that combines palaeodrainage and associated coastal sediments.

This First Edition map, issued in May 2007, is a working version aimed at meeting current demand but will necessarily require modification prior to release as a Second Edition GIS product that can be integrated with other spatial data sets.

Construction and Compilation - The First Edition

A ‘palaeo-drainage and palaeo-coastal systems’ approach (e.g. Alley & Lindsay, 1995; Hou, 2004; Hou & Alley, 2003; Hou & Mauger, 2005; Hou & Warland, 2005; Hou et al., 2000, 2001a, b, 2003a, b, c, 2006; Fabris, 2002, Fabris et al., 2004; Fairclough et al., 2006) underpins the construction of this thematic map. Palaeochannels, palaeocoastal barrier facies and strandlines for interpreted time intervals are shown along with selected mineral occurrences and deposits, and ‘essential ingredients’, which include geological factors that may contribute an increased potential for palaeodrainage-related mineralisation, in particular uranium (Fabris et al., 2004; Fairclough et al., 2006; Hou et al., in prep.) and heavy minerals (Fabris, 2002; Hou & Warland, 2005; Hou et al., 2003b).

It should be noted that surface expression (eg., topographic lows) of palaeochannels is ‘obvious’ only in parts of the western (eastern margin of the Eucla Basin) and central Gawler Craton, Musgrave Province and Adelaidean Fold Belt. Elsewhere (eg., Curnamona Province, Officer and Eromanga basins), the extent of the surface expression is generally very poor, and almost all the Curnamona Province, Central Officer, Eromanga and Murray basins is obscured by sedimentary cover and regolith that ranges from a few metres to tens of metres in thickness.

Data Sources

Much of the information for these covered areas is therefore based on the integration of drillhole sample data, interpretation of remotely sensed data (particularly night-time thermal imagery), geophysical (particularly AEM and TEM where available) data, and knowledge of continental sedimentation and sedimentary history of South Australia (Rogers and Zang, 2006).

The methodology used for the integration and interpretation of these geoscientific data is described in Fabris (2002), Hou and Mauger (2005), Hou et al. (2001a) and Zang and Stoian (2006).

The Palaeodrainage and Tertiary Coastal Barriers of South Australia Map

The principal ‘essential ingredients’ displayed on the map, and detailed below, are as follows:

1. Palaeodrainage divide based on (palaeo-) topographic highs interpreted from palaeodrainage patterns combined with NOAA night-time thermal imagery draped over SRTM DEM image
2. Mesozoic, Palaeogene and Neogene channels were mapped separately with drillhole confirmation locally. In the Eromanga Basin interpreted Mesozoic channels, overlain locally by Tertiary and Quaternary sediments, developed most probably during Late Mesozoic regression. Their interpreted positions are more speculative than for Tertiary drainage and have been derived largely from NOAA night-time thermal images draped over SRTM DEM imagery with drill hole confirmation locally
3. Tertiary barrier facies and strandlines were interpreted based on NOAA and Landsat TM7 (Murray Basin) night-time thermal images draped over SRTM DEM (Shuttle Radar Topography Mission, digital elevation model) image with drillhole confirmation locally
4. Stratigraphic units were derived mainly from references listed below and SA Geology (Volume 2)
5. Geological Provinces (cratonic basement) and Phanerozoic basins and provinces of South Australia outlined by Geological Survey of South Australia
6. ‘Hot’ granitic rocks (eg., Gawler Ranges-Hiltaba Volcano-Plutonic Association) displayed as potential uranium sources for nearby palaeodrainage sediments.

Selected mineral deposits and occurrences, and key drillholes and sections will be shown for reference in the Second Edition.

Feedback on the First Edition (May 2007) can be directed to Baohong Hou (email: baohong.hou@sa.gov.au , phone: +61 8 8463 3038) and will be considered for the Second Edition.

Availability

A low-resolution PDF image of the map is available through the following link (new version with minor changes uploaded 14 May 2007):

Palaeodrainage and Tertiary Coastal Barriers of South Australia (PDF - 3.9Mb).

A higher resolution zipped version of the map (zipped PDF - 6.4Mb) is also available, along with preliminary data in a zip file (1.4 Mb) containing MapInfo and ShapeFile datasets.

A CD with high-resolution print files and PDFs, or a printed copy of the map, are available from the Customer Service Centre. The map is designed to be printed at 1:2,000,000 scale, but may be printed at other scales if desired.

Notes for Specific Coverages

NOAA data and image

NOAA night-time thermal data covering South Australia were derived from NOAA 15 with a resolution of 1100 m at 19:54 (GMT) 11 August 2006. Excessive ‘noise’ in the data (eg., cloud and daily moisture variation in shallow sediments), required that some 28 NOAA night-time thermal images covering South Australia and derived at different times and from different satellites were used to aid the compilation of the map.

ASTER data and image

ASTER night-time thermal data covering some mining areas (eg., Jacinth, Challenger, Four Mile and Beverley) were derived from AST_L1B at 03:39:26 (GMT) 14 November 2006 and at 23:50:27 (GMT) 23 April 2007, with a resolution of 90 m.

SRTM DTM data image

Original data covering South Australia were acquired as SRTM version 2 data from United States Geological Survey and processed by the Geoscientific Information Management Team, Department of Primary Industries and Resources South Australia. This is displayed as a RGB image on the map with a resolution of 90 m pixel.

Geochronology

Palynological data used for the map comes from the following sources: SAGeodata; Hou et al. (2001a), (2006), Stoian and Hou et al (unpublished PIRSA data). U-Pb (zircon) data are from Reid and Hou (2006), Hou et al (unpublished PIRSA data).

References

note: Report books can be found using the Reoprts (SAMREF) Database under the "Information" heading in SARIG Use the format YYYY/NNNNN e.g. 2004/00001).

Bibliographic Reference

Hou, B., Zang, W., Fabris, A., Keeling, J., Stoian, L and Fairclough, M. (compilers), CRC LEME, Geological Survey, Primary Industries Resources South Australia. Palaeodrainage and Tertiary Coastal Barriers of South Australia. Digital Geological Map of South Australia, 1:2 000 000 Series (1st Edition).

Compiled by Hou, B., Zang, W., Fabris, A., Keeling, J., Stoian, L and Fairclough, M. (CRC LEME, Geological Survey, PIRSA) with contributions by Mauger, A and Sheard, M. (CRC LEME, PIRSA), Katona, L., Petrie, S., Cowley, W., Reid, A., Davies, M. and Conor, C., Robertson, S. and McGeough, M. (Geological Survey, PIRSA), Frakes, L.A. (Adelaide University), Stamoulis, V. (previously Geological Survey, PIRSA).

Cited References

Alley N. F. & Lindsay J. M. (Compilers) 1995. Chapter 10: Tertiary. In: Drexel J. F. & Preiss W. V. eds. The Geology of South Australia, Vol. 2: The Phanerozoic, pp. 151–217. Geological Survey of South Australia Bulletin 54.

Fabris, A., 2002. Thermal satellite imagery, - an aid to heavy mineral sand discoveries. MESA Journal, 24: pp. 24-26.

Fabris, A.J. (Compiler), Conor, C.H.H., Crooks, A.F., Burtt, A.C, 2006. Uranium prospects of the southern Curnamona Province and cover sequences, South Australia. South Australia, Department of Primary Industry and Resources South Australia Report Book 2004/022.

Fairclough, C.M, Fabris, J.A., Hou, B. and Daly, S.J., 2006. Uranium: South Australian state of play. MESA Journal, 41: 8-11.

Hou, B., 2004. Palaeochannel studies related to the Harris Greenstone Belt, Gawler Craton, South Australia: Architecture and evolution of the Kingoonya Palaeochannel System. South Australia, Department of Primary Industry and Resources South Australia Report Book 2004/1.

Hou, B. and Alley, N.F., 2003. A model for gold and uranium dispersion and concentration in residual and transported regolith along palaeodrainage systems. - A case study from the central Gawler Craton, SA. MESA Journal, 30, 49-53.

Hou, B. and Mauger, A.J., 2005. How well does remote sensing aid palaeochannel identification? -an example from the Harris Greenstone Belt, SA. MESA Journal, 38, 46-52.

Hou, B. and Warland, I., 2005. Heavy mineral potential of Eucla Basin, SA. - A world-class palaeo-beach placer province. MESA Journal, 37, 4-12.

Hou, B., Frakes, L., Alley, N. F., Stamoulis, V., and Rowell, A., 2000. Geoscientific signatures of Tertiary palaeochannels and their significance for mineral exploration in the Gawler Craton. MESA Journal, 19, 36-39.

Hou, B., Frakes, L.A. and Alley, N.F., 2001a. Development of geoscientific models for the exploration in Tertiary palaeochannels draining the Gawler Craton, SA. South Australia, Department of Primary Industry and Resources South Australia Report Book 2001/021.

Hou, B., Frakes, L.A. and Dodds, A.R., 2001b. Recent drilling in the Garford Palaeochannel, the Gawler Craton – testing of a model derived from interpreted geological, geophysical and spectral methods. MESA Journal, 20, 24-27.

Hou, B., Frakes, L.A., Alley, N.F. and Clarke, D.A., 2003a. Characteristics and evolution of the Tertiary palaeovalleys in the NW Gawler Craton, South Australia. Australian Journal of Earth Sciences, 50, 215-230.

Hou, B., Frakes, L.A., Alley, N.F. and Heithersay, P. P., 2003b. Evolution of beach placer shorelines and heavy-mineral deposition in the eastern Eucla Basin, South Australia. Australian Journal of Earth Sciences, 50, 955-965.

Hou, B., Frakes, L.A., Alley, N.F., Gammon, P. and Clarke, J.D.A., 2003c. Facies and Sequence stratigraphy of Eocene valley fills in Eocene palaeovalleys, the eastern Eucla Basin, South Australia. Sedimentary Geology, 163, 111-130.

Hou, B., Alley, N.F., Frakes, L.A., L. Stoian, L. and Cowley, W.M., 2006. Eocene stratigraphic succession in the Eucla Basin of South Australia and correlation to major regional sea-level events. Sedimentary Geology, 183: 297-319.

Hou, B., Frakes, L., Alley, N. F., Stamoulis, V., and Rowell, A., 2000. Geoscientific signatures of Tertiary palaeochannels and their significance for mineral exploration in the Gawler Craton. MESA Journal, 19, 36-39.

Hou, B., Fabris, A.J., Keeling, J.L. and Fairclough, M.C., in prep. Sedimentary uranium signatures and exploration models, southern Australia. MESA Journal.

Reid, J. A. & Hou, B., 2006. Source of heavy minerals in the Eucla Basin palaeobeach placer province, South Australia: age data from detrital zircons. MESA Journal, 42: 10-14.

Rogers, P.A., 2000. Tertiary palaeodrainage of South Australia. South Australia, Geological Survey. Digital Geological Map of South Australia, 1:2 000 000 Series (2nd edition).

Rogers, P. A. and Zang, Wen-long. 2006. Guide to the sedimentary cover of the central Gawler Craton (Harris Greenstone Belt region). South Australia. Department of Primary Industries and Resources. Report Book 2006/001.

Zang, W.L. and Stoian, L., 2006. Tertiary-Quaternary land evolution of the northwestern South Australia. In: Fitzpatrick, R.W. and Shand, P (eds). Regolith 2006: Consolidation and dispersion of ideas, Proceedings of the CRC LEME Symposium, Hahndorf, November 2006: 372-377.

Acknowledgements

This map represents results of collaborative projects between Adelaide University, CRC LEME and the Geological Survey Branch of Primary Industries and Resources South Australia (the Geological Survey of South Australia is now part of the Department for Manufacturing, Innovation, Trade, Resources and Energy (DMITRE)), from 1998 to 2007. Study of the palaeovalley architecture and sediment fills has benefited from a number of projects, including IGCP Project 514 (Fluvial Palaeo-Systems: Evolution and Mineral Deposits), particularly supported by PIRSA (now DMITRE), the University of Adelaide, Geoscience Australia, CSIRO, Iluka Resources Limited, and Dominion Exploration Limited, through CRC LEME. We also wish to thank companies that provided access to data and samples: Adelaide Resources, SXR Uranium One (formerly Southern Cross Resources) InterMet, Dominion Resources, Minotaur Exploration, Monax, Heathgate Resources, Curnamona Energy. Special thanks are due to Larry Frakes (Adelaide University), Neville Alley, Mike Sandiford, Paul Rogers, Mark Benbow, Malcolm Sheard, Mel Lintern, David Gray, Anthony Reid, Marc Davies, Colin Conor, Andrew Rowett, Paul Gammon, Jonathon Clarke, Brian McGowran, Wayne Cowley, Mark Paine, and Alistair Crooks for their thoughtful comments and constructive criticisms. Lyn Broadbridge is acknowledged for palynological sample preparation of basin and channel sediments respectively. Thanks to Wayne Cowley for his contribution during revision of the stratigraphy through the Stratigraphy Commission of the Geological Society of Australia. Alan Mauger, Vicki Stamoulis, Stephen Petrie (SRTM – raw data USGS) and Luisa Ruperto are acknowledged for providing assistance by processing remotely sensed data.