Wairakei Formation, New Zealand: Stratigraphy and correlation

We propose that various rhyolitic pumice deposits in the Taupo Volcanic Zone and beyond, that were previously called Wairakei Breccia, Waitahanui Breccia (in part), Oruanui (Pumice) Formation, and Kawakawa Tephra Formation, are the products of one large eruption at 20 000 years B.P. On grounds of precedence we name these voluminous deposits Wairakei Formation and suggest that other names be made redundant. Correlations across New Zealand and into the Southwest Pacific basin are presented, together with data from a stratigraphic drillhole near Taupo. The large volume of water inferred to have taken part in magma-water explosive interaction came from proto-Lake Taupo. The correlation of these 20 000 year old deposits, previously thought to be different ages, has a bearing on the age of the Huka Falls Formation and the late Quaternary history of the Taupo district and the Waikato River.