A volcanic neck or plug is formed when magma from an existing volcano solidifies in the pipe or neck and the surrounding sediment is eroded away.
12.
The term'Long Neck', originally used to describe the shape of the land land between Pinhorne ( now Penhorn ) Creek and the Hackensack River, has been adapted to refer to the volcanic neck of the ridge.
13.
It is an eroded 16-million-year-old volcanic neck, named for its similarity to a lying male lion when viewed from the rear ( shore side ), Lion Rock is immediately visible to visitors as they descend along the only access road.
14.
Because the deposits thin towards the north, and there are few signs of volcanic necks within the Ochil Hills themselves, it is thought that the eruptive centres were south of the fault, however these are buried deep beneath the Carboniferous rocks including coal measures which are found beneath the low-lying carse lands to the south.
15.
Following his death, the executors of his estate gifted 100 acres ( 42 hectares ) of land at Piha to the Auckland City Council; this was supplemented in 1963 by the gift of Lion Rock ( Te Piha ), an eroded 16-million-year-old volcanic neck, that was acquired by two of his sons, Acland and Norman, from Te Kawerau in 1941.
