Relation of the Earthquake Flat Breccia to the Rotoiti Breccia, Central North Island, New Zealand

Abstract

Tephra correlations demonstrate that the rhyolitic pyroclastic flow and airfall deposits of the Earthquake Flat Breccia Formation were erupted immediately following the eruption of the Rotoiti Breccia Formation dated (NZ1126) at 41,700 ± 3,500 yr B.P. The two eruptive centres are 26 km apart. A widespread airfall tephra accompanying the eruption of the Earthquake Flat Breccia has previously been regarded as part of the Rotoehu Ash component of the Rotoiti Breccia Formation. All the field correlations are confirmed and others are directly established by the distinctive chemical content of titanomagnetites in the pyroclastic deposits studied.