Lithology and hardness of shore platforms and surficial large boulders at Turakirae Head, New Zealand

Abstract

Turakirae Head, at the southern end of the North Island of New Zealand, has a sequence of up to five marine terrace and gravel barrier couplets, believed to be associated with coseismic uplift during the Holocene. Examination of the present shore platform and last raised marine terrace was made in order to provide an indication as to the origin of the material on them. A record of the lithology of the shore platform and boulder material was made and a type N Schmidt Hammer was used to assess the relative hardness of the rocks. Results indicate that the boulders are more resistant than the shore platform material, and they are not derived in situ since there are lithological differences with the underlying shore platforms. It is suggested that the large boulders are derived from mass movement processes on the hinterland.