Abstract:
An integrated approach to landform genesis which incorporates morphological and sedimentological analysis with geophysical technologies, such as Ground Penetrating Radar (GPR) enables the internal structure and geometry of landforms to be better understood. Such an integrated approach to landform genesis was developed and tested as a case study, to develop depositional models for moraines at the Mueller Glacier, New Zealand. The sedimentary composition of the moraines surrounding the Mueller Glacier was characterised as supraglacial, glaciofluvial, englacial, and ice marginal deposits. The internal structure of the right lateral moraines was dominated by glaciotectonic deformation, collapse features, glaciofluvial activity and surface-parallel down-glacier dipping beds. These moraines are compound polyepisodic landforms formed as ice contact fans that are influenced by repeated advancement/thickening and retreat/down wasting of the ice margin. The terminal moraines and left lateral moraines were subdued single ridges. Terminal moraines were characterised by steep ice marginal slopes and gentle ice distal slopes with an internal composition of down glacier dipping sediments while the left lateral moraines were characterised by steeply dipping up glacier reflections. These moraines where inferred to be ice contact fans formed by ice marginal deposition and debris flow, which have subsequently been deformed via remobilisation of the sediment after ice retreat. The case study of the Mueller Glacier has shown that the use of ground penetrating radar is beneficial in the understanding of glacial geomorphology.
