Rattenbury, M.S. 2025 Sub-Quaternary geological map of southern Aotearoa New Zealand. Lower Hutt, NZ: Earth Sciences New Zealand. GNS Science report 2025/25. 29 p.; doi: 10.21420/AW7N-9S56
Abstract
A sub-Quaternary geological map dataset for northern, western and southern Te Waipounamu South Island and Rakiura Stewart Island provides an interpretation of the continuity of rocks beneath Quaternary sediments, lakes and near-coast sea. These rocks include the Austral Superprovince basement rocks of the Western Province, Tuhua Intrusives and some adjacent Eastern Province, as well as overlying Late Cretaceous–Pliocene sedimentary and volcanic deposits.The sub-Quaternary dataset compilation has involved extrapolation and interpolation of mapped seamless 1:250,000 surface geology, with additional subsurface information provided by local stratigraphic knowledge, borehole logs and geophysics, principally interpretation of aeromagnetic image data. The sub-Quaternary dataset has enabled more efficient improvements to the basement geology without the geometrical complications of overlying surficial sediments. Most of these improvements relate to plutonic rocks where new analytical data and aeromagnetic interpretation have guided boundary changes, and 49 newly identified and 30 previously identified plutons have had their extents defined or adjusted. The newly interpreted plutons and incorporated geochronological, geochemical and petrogenetic suite-affiliation data constitute the map geometry of a companion pluton properties atlas. (auth)
