Some Observations on Periglacial Morphogenesis in the Southern Alps, New Zealand

Abstract

The main components of the land surface in a small area of the Southern Alps of New Zealand have been produced during the glacial-periglacial episodes of the Late Pleistocene. In ice free areas, morphogenesis was associated with congelifraction and the production of scree. Where scree accumulated, slopes evolved towards a smooth, regular form, only slightly concave, characterized by a scree-veneered upper slope passing downslope to a talus zone. On some valley sides, a colluvial foot slope was formed at the base of the talus. It probably resulted from slope wash. Where valley glaciers were present Richter's denudation slope formed alongside the ice. In most cases such slopes were rejuvenated during subsequent stadials, as the result of a retrogressive glacial history, and have been dissected by chutes and funnels to provide the scree now mantling old glacial walls. Fluvial processes were active at least during the waning phases of the cold-climate periods and built alluvial fans at the margins of the glacial troughs. It is believed that similar morphogenesis occurred during the glacial-periglacial phases of the Late Pleistocene in a large area east of the Main Divide in the Southern Alps.