SOILS OF THE BAY OF PLENTY

Abstract

The Bay of Plenty is a crescent-shaped strip of land facing northward into the Pacific Ocean between East Cape and Coromandel Peninsulas. These two peninsulas are the coastal ends of two high ridges that are more than 100 miles apart across the Bay of Plenty but converge southward at right angles. The triangular area between the two ridges was a crustal depression in which a very active zone of volcanism developed, and during the Quaternary, lava, pumice, ashes, and dust were erupted at many different times and places. The lava spread out in flattish sheets that form a series of plateaux rising in irregular steps towards the Taupo district. There is no clear topographic division for the southern boundary of the Bay of Plenty district, and for purposes of this paper the district is the watershed of the streams and rivers draining into the Bay of Plenty between Waihi Beach on the west and Waihau Bay on the east. The headwaters of the Rangitaiki, Whakatane, and Motu Rivers are excluded, as they extend deeply into adjacent districts