The Kauri (Agathis Australis) is a kind of conifer living in only the sub-tropical climates of New Zealand. The first of them appeared during the Jurassic period about 190/135 million years ago. They are the world's biggest trees in terms of trunk volume and have a height of up to 70 meters and a width of up to 9. Unfortunately many of their forests were felled by English colonists on arrival for the sake of timber or land for farming. All the remaining trees are now under governmental and legal protection.
The biggest surviving Kauri is the 'TANE MAHUTA' or 'LORD OF THE FOREST' in the Maori language.
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About 50,000 years ago, at the end of the last ice age, a series of unexplained cataclysms submerged whole forests of kauris in water and mud. The specific qualities of the mud and the absolute lack of oxygen exempted these plants, trapped in the swamps for 30-50 thousand years, from the chemical processes of decomposition and petrification, letting them linger intact to the present day in veritable 'wood mines''. What is unique is the fact that, in spite of being buried in mud for thousands of years, the trunks are perfectly preserved and have the same quality as timber just felled. Briers have been found clambering up the trunks for up to 30 meters. The abundance of resin within the burls gives an impression of gold due to a change of the resin's amber into what looks like gold powder.
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These kauris were in great prehistoric swamps which have been drained. Once a deposit has been located, it can be extracted with excavators and bulldozers. Recovery operations are difficult due to the muddy and infirm terrain in places hardly accessible and to the notable size of trunks, which can be lifted by only heavy equipment. The trunks may weigh up to 200 or 300 tons, so operators have to cut them into two or more parts before being able to lift them and take them away. Parts of the trunk are then cut into boards in a most delicate operation which calls for long and careful processing to obtain a constant thickness, which requires a system of tangential cutting to minimize moving the enormous trunks. The rainy winters and the swampy terrain force operators to do the excavating in only the dry season and to devote the months of winter to working on and finishing the materials. Once they have been extracted, these plants are dated with the Carbon 14 method by the laboratories of the University of Auckland. The ages of the plants vary from 7,000 to 50,000 years, as may be seen in terms of their various shades of colour.
