Nambour Basin
Last updated:27 June 2014
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.
- ProvExplorer - Nambour Basin Details and Geological Overview
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 |
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| 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 |