| MARYBOROUGH BASIN | ||
|---|---|---|
| State(s) | Queensland | |
| Area (km2) | Offshore | 15,500 |
| Onshore | 9,100 | |
| Maximum thickness (m) | 9,500 | |
| Age Range | Late Triassic to Cainozoic | |
| Basin | Overlies | Permo-Triassic metasediments and granites. |
| Underlies | Cainozoic fluvial, coastal and shelf cover. | |
| Subdivisions | - | |
| Other | Grades into the Nambour Basin to the south. | |
| Indicators | Knowledge | Outcrop, regional geophysical some well data onshore; regional geophysical data only offshore. |
| Basin type | Probable back-arc basin. | |
| System(s) | Murta | |
| Water Depth (m) | 0 - 1,000 (mostly < 200) | |
| Exploration | Status | Frontier |
| Wells | Four petroleum exploration onshore, 0 offshore. | |
| Seismic line-km | Not determined, but sparse 2D only. | |
| Discoveries | Nil | |
| Shows | Gas show in Gregory River-1. | |
| HC evidence | - | |
| Geology | Source(s) | Early to Middle Jurassic continental shales and coals; Early Cretaceous marine shales and fluvio-deltaic to lacustrine shales and coals. |
| Reservoirs | Sands within the Early Cretaceous Maryborough Fm, in particular the Gregory Sandstone Member. | |
| Seals | Intraformational Maryborough Fm shales. | |
| Trap types | Structural traps predominate. | |
| Palaeogeographic summary | Late Triassic: fluvial; Early to Middle Jurassic: fluvio-lacustrine; Late Jurassic: mainly continental volcanics; Early Cretaceous: estuarine and coastal to marine, then coaly fluvio-deltaic and lacustrine; Late Cretaceous hiatus; Palaeogene: fluvial. | |
| Timing | Oil generation | (?) Late Jurassic - Early Cretaceous. |
| Gas generation | Late Cretaceous to Neogene. | |
| Trap formation | Late Cretaceous. | |
| Other key times | Late Jurassic to Early Cretaceous uplift; further Late Cretaceous uplift and major erosion (2 - 3 km of section removed onshore). | |
| Other important information | 1) The offshore Maryborough Basin underlies whale migration paths for
several months of the year. 2) Fraser Island is a National Park. |
|
| Geoscience Australia products available | Hill, 1994. Record 1994/1. | |