
The geological history of New South Wales is very complex and spans almost two billion years of Earth history.
During this time there have been multiple phases of active continental growth, involving periods of widespread volcanic activity, sedimentation (in near-shore basins and in deep-sea areas), granite intrusion and intense folding and faulting as a consequence of the processes of plate tectonics.
These geological processes have resulted in the formation of new or additional areas of crust in the form of mountain chains or orogens. Over time, these mountain chains have been eroded to produce the overall subdued topography we see now.
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