[5] Thus the tectonic processes involved in the formation of the Hauraki Rift[6] and Coromandel Volcanic Zone in the continent of Zealandia have moved from the north to the south over the last 20 million years.

[5] The oldest volcanic rocks at the northern tip of the Coromandel Peninsula are the Port Charles andesites that are dated from about 18 million years ago.

[5] After this stage it is postulated that the Kapowai Caldera, the largest in the zone, located in the centre of the Coromandel Range (peaks of Table mountain, The Pinnacles, Tanehua) formed.

[5] This formed the volcanic structures around Waihi later important in precious metal discoveries due to subsequent hydrothermal mineral deposit formation.

[7] Geothermal activity is still present in the Zone,[8] with hot springs in several places, including at Hot Water Beach, on the central east coast between Whitianga and Tairua and on the south western margins of the Zone near Te Aroha where there is only natural soda water geyser in the world.

[9] There are mineral deposits such as gold in quartz reefs associated with past geothermal and volcanic processes.