The soils underlying much of central Rotorua include several metres of diatomaceous silts and pumiceous sands. The properties of these complex soils are often outside the ranges used to establish the current liquefaction criteria, and the assumptions and simplifications made in establishing these criteria may therefore be invalid for the Rotorua area. Cone penetration tests give low results for both cone resistance and sleeve friction which may affect the accuracy of the resulting parameters. These factors make it difficult for the local geotechnical community to reliably predict the liquefaction potential of these soils. This paper provides an introduction into the topic. A review of the existing research on the properties of similar soils is presented and recommendations are given for further research to increase our understanding of the seismic behaviour of these soils.