Geology
The dome-shaped mass is composed of granophyre that formed below the surface and subsequently intruded into the overlaying sandstone. Erosion has stripped away the sandstone leaving the mountain's twin peaks.
Mount Barney is the remnants of the central complex of the Focal Peak Volcano which together with the Tweed Volcano covered much of South East Queensland and North East New South Wales with lavas referred to as the Lamington Volcanics
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