NGARINO TERRACE - ADDITION TO LATE PLEISTOCENE STANDARD SEQUENCE IN WANGANUI-TARANAKI DISTRICT

The coastal “terrace” formerly mapped as the Rapanui Terrace consists of two terraces and the name Rapanui is restricted to the younger of them. The name Ngarino is proposed for the older terrace. The sedimentary cover of the Ngarino Terrace (Ngarino Formation) and pollen assemblages for its upper part are described. Like that of the other coastal terraces in the district it consists of a basal marine pebbly sand (Sherwood Sand) overlain by terrestrial deposits (dune-sands, ash, and carbonaceous silts). None of the pollen assemblages indicates cold climates and most of the deposits are thus classed as interglacial. Whether the Ngarino and Rapanui Formations represent separate interglacial stages cannot be determined on the data available. Both terraces may have been formed during the Last Interglacial. On the other hand, accepting correlation with Taranaki, the deposition of a ring plain of lahar agglomerate (Lepperton Lahars) between the times of formation of the two marine terraces suggests that they were separated by a glacial phase, since other ring plains in Taranaki accumulated at times of glacial climate. © 1974 Taylor & Francis Group, LLC.