Tweed Volcano

Tweed Volcano
After activity ceased, the volcano rapidly eroded. Pictured here is Mount Warning, a volcanic plug that marks where the summit used to be.
Highest point
Elevation	~1,900-2,312 m (6,200-7,586 ft)
Geography
Location	Northeastern New South Wales
Parent range	Great Dividing Range
Geology
Age of rock	Over 23 Million Years
Mountain type	shield volcano
Last eruption	~23 Ma

Tweed Volcano is a partially eroded Early Miocene shield volcano located in northeastern New South Wales, which formed when this region of Australia passed over the East Australia hotspot around 23 million years ago.^[1] Mount Warning, Lamington Plateau and the Border Ranges between New South Wales and Queensland are among the remnants of this volcano that was originally over 100 kilometres (62 mi) in diameter and nearly twice the height of Mount Warning today, at 1,156 metres (3,793 ft). Despite its size, Tweed Volcano was not a supervolcano; other shield volcanoes—such as in the Hawaiian Islands—are much larger. In the 23 million years since the volcano was active, erosion has been extensive, forming a large erosion caldera around the volcanic plug of Mount Warning.^[2] Its erosion caldera is the largest in the Southern Hemisphere.^[3]