Mount Kahuranaki, Hawkes Bay, New Zealand, A klippe emplaced by gravity sliding from the crest of the nearby Elsthorpe Anticline

Abstract

Mount Kahuranaki consists of various calcareous lithologies of the Te Aute Formation, Waipipian Stage, Pliocene, developed in a stratigraphic section which differs markedly from that of Te Aute Formation in the immediately adjacent areas. Mapping of lithological units defines the structure of the Kahuranaki Klippe, an allochthonous mass 3 km long and 2 km wide. The main element is an eastward verging, northeast-trending anticline which has been fractured by a complex set of predominantly extensional faults. The klippe rests discordantly on the gently dipping Te Aute Formation of the Maraetotara Plateau and lies in a pronounced structural depression within a sinistral bend of the immediately adjacent Elsthorpe Anticline. We consider the Kahuranaki Klippe to represent a portion of the hinge of the Elsthorpe Anticline which became detached and slid to the east because of oversteepening due to the bending of the anticline. The sliding took place under near-surface, possibly non-marine, conditions.