Nambour Basin

Location Map

Nambour Basin in relation to Australia

Map showing the location of Nambour Basin in relation to Australia
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Basin Details and Geological Overview

The Late Triassic-Early Jurassic Nambour Basin is a small, frontier, intracratonic basin in southeastern Queensland. The basin covers some 9 500km2, of which 2 500km2 lies offshore under water depths of up to 200 metres. The western boundary of the basin abuts Palaeozoic rocks of the D'Aguilar Block (to the northwest) and the Beenleigh Block (to the southwest). The southern basin overlies Palaeozoic basement and Lower Triassic sediments of the Ipswich Basin, whilst to the north the Nambour Basin grades into the Maryborough Basin. Structures in the Nambour Basin trend mainly north-northwest.

The geological evolution of the Clarence-Moreton, Surat, Eromanga, Nambour and Mulgildie Basins followed a Late Triassic Norian orogeny. Uplift at the end of the orogeny exposed the newly stabilised craton to erosion, with sediments being deposited in relatively small intermontane basins and structural depressions. The depositional history of the Nambour Basin parallels that of the eastern half of the Clarence-Moreton Basin. A comparable suite of high-energy fluviatile quartzose sandstones and polymictic conglomerate was deposited on the eroded surface of the Ipswich Coal Measures during the Late Triassic (Rhaetian). Following this up to 120 metres of quartzose and sub-labile sandstone interbedded with siltstone, mudstone and minor coal was deposited under less energetic fluviatile conditions. During the Early Jurassic, up to 400 metres of fine to medium grained sub-labile to labile sandstones were deposited under fluviatile and lacustrine conditions. The Nambour Basin has a limited sediment pile of 600 metres, with good reservoir but limited seal potential. Vitrinite reflectance data suggests that the sequence was significantly thicker in the past. Minor gas shows have been recorded in most of the basin's four petroleum exploration wells. Any hydrocarbons (probably gas) would be sourced from the underlying Ipswich Basin, but the Nambour Basin is regarded as being unlikely to contain commercial quantities of hydrocarbons.

Basin Summary table

State(s) Queensland
Area (km2) Offshore 2500 (but poorly known)
  Onshore 7 000
Maximum thickness (m) 600
Age Range Late Triassic to Early Jurassic.
Basin Overlies Permo-Triassic Gympie Block.
  Underlies Latest Paleogene volcanics and Neogene coastal sediments.
  Subdivisions -
  Other Grades into the Maryborough Basin to the north.
Indicators Knowledge Good outcrop, regional geophysical and some well data onshore; limited geophysical and one well offshore.
  Basin type Intracratonic sag.
  System(s) Murta
  Water Depth (m) 0 - < 200
Exploration Status Frontier
  Wells 5 petroleum (4 onshore, 1 on an offshore island), plus numerous water wells.
  Seismic line-km Not determined, but very sparse.
  Discoveries Nil
  Shows Nil
  HC evidence Nil
Geology Source(s) The underlying Ipswich Basin is a possible source.
  Reservoirs 'Landsborough Sandstone'.
  Seals None identified; Cainozoic volcanics possible seal.
  Trap types Gentle anticlines in theory could form traps.
  Palaeogeographic summary Predominantly fluvial, but fluvio-lacustrine at top with possible brief marine incursion.
Timing Oil generation No evidence of generation from the Nambour Basin; Jurassic for the Ipswich Basin, but any oil is likely to have been cracked to gas in the Early Cretaceous.
  Gas generation No evidence of generation from the Nambour Basin; Jurassic to Neogene for the Ipswich Basin.
  Trap formation Late Cretaceous.
  Other key times Jurassic-Cretaceous intrusions; Late Cretaceous folding; latest Paleogene volcanism.
Other important information
  1. The offshore basin lies under a whale migration path for several months of the year.
  2. A detailed Southeast Queensland dataset that includes the onshore basin is available from the Queensland Department of Natural Resources and Mines.
  3. The onshore basin includes National Parks.
  4. The onshore basin includes large urban areas.
Geoscience Australia products available -

Key References

Author(s) Year Title
Cranfield, L.C. and Schwarzbock, H. 1976 Nambour Basin. In R.B. Leslie, H.J. Evans and C.L. Knight, (Editors), Economic geology of Australia and Papua New Guinea. Volume 3. Petroleum. Australasian Institute of Mining and Metallurgy, Monograph Series, 7, 460-464
Day, R.W., Cranfield, L.C. and Schwarzbock, H. 1974 Stratigraphy and structural setting of Mesozoic basins in southeastern Queensland and northeastern New South Wales. In Denmead, A.K., Tweedale, G.W. & Wilson, A.F. (Editors). The Tasman Geosyncline, a Symposium. Geological Society of Australia, Queensland Division, 319-363
Day, R.W., Whitaker, W.G., Murray, C.G., Wilson, I.H. and Grimes, K.G. 1983 Queensland geology, a companion volume to the 1:2,500,000 scale geological map (1975). Geological Survey of Queensland Publication, 383, 123-132
Goscombe, P.W. and Coxhead, B.A. 1995 Clarence-Moreton, Surat, Eromanga, Nambour and Mulgildie basins. In Geology of Australian Coal Basins, Ward, C.R., Harrington, H.J., Mallett, C.W., & Beeston, J.W., (Editors). Geological Society of Australia, Coal Geology Group, Special Publication, 489-511
Green, P.M. and Armstrong, K.L. 1986 Baroon Pocket Dam. Petrological report, Black Range Tunnel. Geological Survey of Queensland, Record 1984/30
Hawkins, P.J. 1984 Review of source-rock sampling in the Moreton, Nambour and Maryborough basins, Queensland. Queensland, Geological Survey, Record 1984/29
Hill, D. 1961 Geology of southeastern Queensland. In Bryan, W.H., Bryan, H., Hill, D. & Woods, J.T. (Editors). Introducing Queensland. Handbook, Australian and New Zealand Association for the Advancement of Science, Brisbane, 1961, 125-135
Hill, D. and Maxwell, W.D.H. 1967 Elements of the stratigraphy of Queensland (2nd edition). Brisbane, University of Queensland Press, 78
McKellar, J.L. 1993 Stratigraphic relationships in the Nambour Basin, southeastern Queensland. Queensland Geology, Vol 5, 1-17
Murphy, P.R., Schwarzbock, H., Cranfield, L.C., Withnall, I.W. and Murray, C.G. 1976 Geology of the Gympie 1:250,000 Sheet Area. Geological Survey of Queensland, Report 96