Ecology of the Subantarctic Islands: Geological history
The geological history of Campbell Island is better known than that of other subantarctic islands because its stratigraphic record is more complete (Oliver, 1950). Apparently the site of Campbell Island was land in the Upper Cretaceous and shared in the peneplanation that reduced the relief of older rocks in southern New Zealand at that time, producing extensive alluvial plains of quartz gravels. The Campbell Island quartz gravels required long transport and chemical weathering for their formation so that the island probably formed part of a large land area. From such geological evidence it might have been linked with New Zealand but Upper Cretaceous pollens and spores from Campbell Island recently studied by R. A. Couper lack the conifer and beech pollens so abundant in the New Zealand Cretaceous, indicating a dispersal barrier, climatic or geographic, between New Zealand and Campbell Island.