Stevens, G.R. 1981 New Zealand's changing geography. Alpha 17. 6 p.
Abstract: Paleomagnetism makes use of magnetism preserved in rocks. Major changes in New Zealand's position can be documented by studying these rocks. The magnetic properties of rocks disappear on heating, thus lava from volcanoes when cooled will have a magnetic alignment towards the North Magnetic Pole. This angle can be determined, and hence the position of New Zealand at that time can be fixed