It provides evidence of the rock types found at great depths in the earths crust but also for plate tectonics and continental drift, the geological processes which have dominated the earths surface for many millions of years.

Macquarie Island is a part of the State of Tasmania and is one of two Australian sub-Antarctic possessions in the Southern Ocean.

It is situated about 1500 km south-south-east of Tasmania, about half way between Tasmania and Antarctica at around 55 degrees south. The main island is approximately 34 km long and 5.5 km wide at its broadest point.

Auckland Island is the closest island to Macquarie. There are numerous sea stacks and reefs close to shore and several small outlying islets as part of the reserve. These are: Judge and Clerk Islets 11 km to the north and Bishop and Clerk Islets about 37 km to the south of the main island. The total area of Macquarie Island is 12 785 ha.

Macquarie Island is a State Reserve with protection extending to low water mark. Although it supports a huge concentration of seabirds (3.5 million) and seals, at present only their breeding sites are protected not their feeding sites, the surrounding sea. Proposals have been made to make a Marine Reserve at Macquarie Island and so protect this vital marine ecosystem.

Macquarie Island is a special place. Its position just north of the Antarctic Convergence makes it one of eight islands or island groups in the sub-Antarctic region. Sub-Antarctic islands lack trees, herbaceous plants are the dominant vegetation type and have a mean annual temperature range from one to five degrees Celsius.

There are no permanent human inhabitants on Macquarie Island. The Australian Antarctic Division station is occupied year round. The only access to the island is by sea and there are no harbours or landing facillities. Ship-traffic in the area is minimal and mainly consists of resupply vessels for the station.