Australia: The Land Where Time Began

A biography of the Australian continent 

The Clarence-Moreton Basin is believed to be an off-shoot of the southeast margin of the Great Artesian Basin, to which it was linked by a narrow strait throughout the Mesozoic (McElroy, 1962). The Queensland portion of the Clarence-Moreton Basin is the only part of the basin within the Murray-Darling Basin, though it extends from southeast Queensland to northeastern New South Wales.

In the Middle Triassic, sedimentation began in the basin that was subsiding slowly, continuing until the Cretaceous. In this deposition cycle, a sequence of coal measures, as well as mature and less mature sandstones was repeated (McElroy, 1962). In Queensland, the Ipswich coal measures, the Bundamba Group and the Marburg Subgroup, comprised the depositional cycle of the Triassic to Jurassic and the Walloon Coal Measures of the Jurassic to Cretaceous depositional cycle.

In shallow flood basins and peat-forming wetlands coal measures were deposited. The fluvial Bundamba Group and Marburg Subgroup conglomerate and sandstone units resulted from the subsidence of the basin and the uplift of its margins. During the Tertiary, intermediate and basic lavas and pyroclastics were extruded extensively (McElroy, 1962).

Sources & Further reading

1. Geology of the Murray-Darling Basin - Simplified Lithostratigraphic Groupings