Dun Mountain-Maitai Terrane | |
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Stratigraphic range: Early Permian-Triassic ~ | |
Type | Terrane |
Unit of | Austral Superprovince |
Sub-units | Dun Mountain Ultramafics Group, Livingstone Volcanic Group, Maitai Group and Otanomomo Complex |
Underlies | Murihiku Terrane, Momotu & Haerenga Supergroups |
Overlies | Caples Terrane |
Lithology | |
Primary | Basalt, gabbro, peridotite, sedimentary rocks |
Other | Jade |
Location | |
Region | Nelson, Tasman, Marlborough, Otago & Southland Regions |
Country | New Zealand |
Type section | |
Named for | Dun Mountain & Maitai River |
Components of the Dun Mountain-Maitai Terrane are coloured green in this map. Light green (10) are Permian ophiolites and pyroclastics and dark green (11) are Permian volcanic rocks. Adjacent are more recent greywacke light blue (2), schists dark blue (3), and the most recent sedimentary deposits are yellow (1). |
The Dun Mountain-Maitai Terrane comprises the Dun Mountain Ophiolite Belt (also called the Mineral Belt), Maitai Group and Patuki Mélange.[1] The Dun Mountain Ophiolite is an ophiolite of Permian age located in New Zealand's South Island. Prehistorically this ophiolite was quarried by Māori for both metasomatized argillite and pounamu (jade) which was used in the production of tools and jewellery.[2]
In the late 1800s, the Dun Mountain Ophiolite Belt was surveyed for its economic potential. During this time the rock types dunite and rodingite (after Dun Mountain and the Roding River) were first named.[3] Discovery of economic deposits of chromite near Nelson lead to the building of New Zealand’s first railway, however, extraction only occurred between 1862 and 1866. In the 20th century, serpentinite was mined for fertiliser and the ophiolite remains one of New Zealand's main sources of pounamu (jade), but all other mineral exploration has failed to find economic deposits.