About NZ Kauri
The most southern-growing species, New Zealand kauri, is restricted to the sub-tropical forests in areas north of latitude 38° S (in Auckland, Northland and the Coromandel Peninsula), where it grows from sea level to 600 metres.
Before people settled in New Zealand, forest containing kauri covered much of the Coromandel Peninsula and northern areas. Today, the remaining 7,455 hectares of mature kauri forest is scattered in remnant patches. Fossil evidence shows that it once grew as far south as Invercargill. Over the last few million years, kauri retreated to its present limits as a result of geological-scale disturbances such as sea-level changes, mountain-building, volcanic eruptions and glaciations, and the associated loss of suitable soils.
About Swamp Kauri:
Swamp kauri timber, also known as ancient kauri, is milled from kauri trees that have been buried and preserved in peat swamps for between 800 and 60,000 years. Some kauri were up to 2,000 years old when they fell.
Swamp kauri is a broad term applied to timber that varies in age and the way it's been preserved. Most swamp kauri is found in Northland but some has been found as far south as Waikato.