Chronology and processes of late Quaternary hillslope sedimentation in the eastern South Island, New Zealand

Abstract

Optical and radiocarbon dating of loessic hillslope sediments in New Zealand's South Island is used to constrain the timing of prehistoric rockfalls and associated seismic events, and quantify spatial and temporal patterns of hillslope sedimentation including responses to seismic and anthropogenic forcing. Trenches adjacent to prehistoric boulders enable stratigraphic analysis of loess and loess-colluvium pre- and post-dating boulder emplacement, respectively. Luminescence ages from loessic sediments constrain the timing of boulder emplacement to between ∼3.0 and ∼12.5 ka, well before the arrival of Polynesians (ca. AD 1280) and Europeans (ca. AD 1800) in New Zealand, and suggest loess accum..