South Island surface volcanism
The volcanic activity in the South Island of New Zealand terminated 5 million years ago as the more northern parts of the North Island became extremely volcanically active. The South Islands surface geology reflects the uplift of the Pacific plate as it collides with the Indo-Australian plate along the Alpine Fault over the last 12 million years and the termination of subduction, about 100 to 105 million years ago.
Source: Wikipedia — South Island surface volcanism (CC BY-SA 4.0)