Mt Wellington - dolerite outcrop.
Mt Wellington - an uplifted mass of mostly dolerite formed around 180 million years ago from magma intrusions of much older mudstone (Permian deposits) and sandstone (Triassic deposits) with a peak elevation of 1271 m..
The large vertical columns of dolerite associated with south-eastern Tasmania rock outcrops such as the mountain 'pipes' (eg the 'Organ Pipes" of Mount Wellington and Ben Lomond) and the 'fluted' cliffs (eg Fluted Cape on Bruny Island) lead some geologists to conclude that the rock formed in sills within the mudstone and sandstone deposits. The much hardier dolerite rock is what remains in these outcrops long after the mudstone and sandstone has eroded away from around it.
The story:
Mt Wellington - dolerite outcrop.
Mt Wellington - an uplifted mass of mostly dolerite formed around 180 million years ago from magma intrusions of much older mudstone (Permian deposits) and sandstone (Triassic deposits) with a peak elevation of 1271 m..
The large vertical columns of dolerite associated with south-eastern Tasmania rock outcrops such as the mountain 'pipes' (eg the 'Organ Pipes" of Mount Wellington and Ben Lomond) and the 'fluted' cliffs (eg Fluted Cape on Bruny Island) lead some geologists to conclude that the rock formed in sills within the mudstone and sandstone deposits. The much hardier dolerite rock is what remains in these outcrops long after the mudstone and sandstone has eroded away from around it.
The story: