Australian Mountain Peaks
Cache Name: AMP040 – Mount Warning
Peak ID: 40
Elevation: 1155m
State: NSW
Location: Tweed Range, New South Wales
Coordinates: S 37 17’34 E 142 36’3”
Cache Size: 500ml plastic container
Mount Warning is in the Tweed Range in the Northern Rivers region of New South Wales, Australia. It was formed from a volcanic plug of the now-gone Tweed Volcano. The mountain is located 14km west-south-west of Murwillumbah, near the border between New South Wales and Queensland. Lieutenant James Cook saw the mountain from the sea and named it Mount Warning.
Mount Warning is the central volcanic remnant of an ancient shield volcano, the Tweed Volcano, which would have been about 1,900m above sea level or just under twice the height of the current mountain. This volcano erupted around 23 million years ago. As the mountain's central vent cooled it shrank, forming a depression at the top that has greatly eroded.
Today the vast areas that were part of the volcano include many mountains and ranges at some distance from Mount Warning, and include the Border Ranges, Tamborine Mountain, the McPherson Range, and both the Lamington Plateau and Springbrook Plateaus. The erosion caldera formed since this eruption is easily visible around the summit and forms the rim of the Tweed Valley.
During the last stages of the eruption, different and more resistant forms of lava that were cooler than those flows that created the shield volcano remained to form the current peak. The whole central Mount Warning massif was also pushed up by forces that remained active after lava eruptions had stopped.
In 2005 the name "Mount Wollumbin" was removed from a peak nearby to Mount Warning by the Geographical Names Board. This mountain is also referred to as Mount Ivy and Mount Dum Dum and was believed to be named Mount Wollumbin in error. In 2006 the Geographical Names Board assigned dual naming to Mount Warning, to also be known by its indigenous name of Wollumbin. The name Wollumbin refers to the whole of the central vent and its surrounding ring dykes.