Named tephras and tephra formations occurring in the Central North Island, with notes on derived soils and buried paleosols

Abstract

Abstract Published names of tephra formations and members are arranged in chronological order, with estimated ages, distribution, and a statement of their mineralogical composition. The clay minerals in surface soils and in buried paleosols derived from them are listed, and the surface soils are classified. The sources of the tephras are mapped, with the 30 cm isopachs of tephras that occur within 45 cm of the surface and the 15 cm isopachs of tephras found between 45 and 100 cm from the surface also shown. The sequence of tephras that are likely to be found within 45 cm from the surface is indicated, also, areas of recent soils from volcanic ash, and a suggested boundary between yellow-brown pumice soils and yellow-brown loams.