MSc in Geography
Glaciotectonic Deformation in Late Pleistocene Deposits at Lake Hawea
Assoc. Prof. Sean Fitzsimons
Glacial geomorphologists are among those that share an interest in the Quaternary, with particular emphasis on the reconstruction of past glacial landscapes which can involve numerous sources of evidence. Glaciotectonic processes, in particular, produce structures and landforms which may be used to reconstruct environmental changes long after the ice has vanished. The nature of these provides evidence which can be used to deduce the conditions present either at the time of deposition, or during subsequent reworking. This research is focused on identifying proglacial glaciotectonic deformation associated with the glaciolacustrine sedimentation bordering Lake Hawea, South Island, New Zealand. A combination of geomorphological, sedimentological, and geophysical techniques are currently being utilised to comprehensively map and analyse landforms and sedimentary deposits. It is from this method that the extent of glaciotectonism can be assessed and, using this evidence, inferences can be made regarding glacial behaviour during the Late Pleistocene. Several glacial troughs, similar to Lake Hawea, are found on the eastern side of the Southern Alps; all of which are a product of Late Quaternary ice advance. One of these is Lake Pukaki where the existence of proglacial glaciotectonic deformation is contested. The variation in interpretation of the glaciolacustrine deposits in this example suggests that the execution of such research varies and a more uniform and thorough approach would prove advantageous. The current research has the potential to test and refine previous depositional models created. Furthermore, it will increase the level of understanding of the Late Pleistocene behaviour of glaciers in a wider regional setting encompassing the eastern side of the Southern Alps.