The islands of New Zealand, best known to the Maori as Aotearoa, have a very interesting geological story.
But before I get into that let me tell you the Maori tale of how the islands came to be…
Maui was always jealous of his older brothers going out fishing without him. One fine day they were going out, and of course, Maui’s desire to go was again rejected. He was too little yet to be out. But Maui would not take no for an answer, and so as his brothers were getting all the fishing gear ready he snuck into the nets on the boat.
So out his brothers went to fish, Maui’s presence unbeknownst to them. Eventually in the afternoon they got tired and decided to have a nap on the boat. They let out the anchor and settled in for some rest. His eldest brother laid down on the nets to hear a squeal underneath him. Startled, he poked the net again, to hear yet another sound. Angry, he pulled Maui out of the nets. Maui persisted in saying he was big enough to fish, and he would show them. He grabbed some line and threw it in the water. Shortly, the line started top pull back, hard. He braced himself against the boat and start to pull the line is as well as he could. Just before he was being pulled in his brothers grabbed him to stop him from swimming. Before their eyes a giant sting ray surfaced, and as it was pulled towards the boat it opened its giant mouth to the boat, with all the brothers in it. Chomping down, it took out a chunk of the boat as it was capsized, sending everyone into the water.
They climbed onto the overturned canoe. The raised middle of the canoe became the Southern Alps. The bottom left hand corner of the boat where it was chewed and filled with inlets is known as Te Wahipounamu, Land of the Greenstone. The anchor of the boat is Rakiura, or Stewart Island. The sting ray Maui fished up is the North Island, for if you look at the shape it resembles a sting ray. This is known as Te Ika a Maui (Maui’s fish). His waka (canoe) the Mahunui became the South Island, or Te Waka-a-Maui (Maui’s waka).
From the Government of New Zealand.
Geologically speaking, New Zealand is quite diverse for its size, but certainly very young compared to Canada. There are four phases in it’s evolution:
- 500-300 Ma Sediments and volcanics followed by collision and uplift: Tuhua orogeny
- 300-85 Ma More volcanism and sedimentation followed by collision and uplift: the Murihiku and Torlesse rocks, the Haast Schist; Rangitata orogeny
- 85-25 Ma Break up of Gondawana, detachment of New Zealand, Tasman Sea opening and sinking of New Zealand
- 25 Ma-present Uplift
I will follow with some posts of each different phase, describing some of the areas I visited along my journey corresponding to the phase in New Zealand’s geological history. My main reference is The Field Guide to New Zealand Geology, by Jocelyn Thornton.