The soil pattern of the King Country is dominated by soils developed on volcanic ash. The ash mantle is made ump of three broad groups: old ashes (Kauroa Ash and Hamilton Ash); middle age ashes (Rotoehu Ash, Oruanui Ash and Mairoa Ash) and young ash (Taupe Pumice). In the western part of the district the most extensive soils are yellow-brown loams formed on Mairoa Ash; in the eastern part, yellow-brown pumice soils on Taupo Pumice. It is only where erosion has partly or completely removed the ashes from the steeper slopes of the hill country that soils (mainly yellowbrown earths) can form on the underlying greywacke, sandstones and mudstones. Recent soils from alluvium, in association with swamps and peat bogs occur in the valleys of streams and rivers. Although the underlying rocks do not contribute extensively to the soils of the district, 'they do give rise to characteristic landscapes - e.g., greywacke gives steep, narrow valleys and ridges: mudstones give hummocky, slumped slopes; limestones give bluffs, isolated towers, dry valleys and tomos and sandstones and ignimbrites give prominent bluffs.
