Sediments of lake pukaki, South Island, New Zealand

Abstract

Lake Pukaki, fed by glacial melt water, is turbid all year round and is subject to an average of four major floods each year. Lake level is controlled by a dam at the south end of the lake. Bottom surface sediments are fine silt and clay, and these become finer down lake; the coarsest sediments are from the delta area and from close to the outlet. Analyses show the samples to contain rougly equal amounts of quartz and albite (43%), and clay minerals. Short cores (47 cm and 15 cm) show alternating light (silt) and dark (clay) layers. It was not determined whether these rhythmic layers are annual deposits, or controlled by flood conditions. © 1972 Taylor & Francis Group, LLC.