Construction of a spinner magnetometer and paleomagnetic measurements on a Pliocenemiocene sedimentary section

Abstract

This thesis describes the instrumentation developed for measuring the low intensities of magnetisation found in sedimentary rocks. A spinner magnetometer has been constructed employing a coil-galvanometer amplifier detection system, and later, a fluxgate system. The instrument has been used to determine the magnetic polarities of samples taken throughout 1000 metres of Pliocene-Miocene sedimentary strata at Hinakura Road, Wairarapa. These polarities have been correlated with accepted magnetic stratigraphies to yield a date for the Miocene-Pliocene boundary in New Zealand of 4.8 M yrs.