The Middle Triassic Ipswich Basin is a small, frontier petroleum basin located in southeastern Queensland and northern New South Wales. The onshore component extends about 8000 km2 and is bounded by the D'Aguilar Block to the north, the Beenleigh Block to the southeast and the Ipswich Fault to the west. The eastern extent of the basin is not well known but probably covers an offshore area of about 1000 km2 under Moreton Bay. The Ipswich Basin is overlain by the Late Triassic to Middle Jurassic Clarence-Moreton Basin in the south and by the Late Triassic to Early Jurassic Nambour Basin in the east.
A period of oblique extension during the Scythian-Carnian led to the deposition of coal measures of the underlying Nymboida Basin. After a hiatus, the Ipswich Basin formed in the Carnian during a period of thermal subsidence. The basin-fill is dominated by sandstones, shales, conglomerates and coals deposited in alluvial, fluvial and lacustrine environments, with some interbedded volcanics. Petroleum exploration in the Ipswich Basin has been limited to 19 wells, half less than 250 metres deep, with numerous unconfirmed oil shows and gas shows, but no commercial discoveries. Potential gas prone source rocks are present in the Ipswich Basin. The poor reservoir quality of sandstones and the lack of regional seals reduce the potential for conventional hydrocarbons. However, potential coal seam methane resources may be present. Coals are an important resource in the Ipswich Basin and are mined at Swanbank.