LOESS FORMATION IN NEW ZEALAND DURING THE LAST GLACIAL EPOCH AND UNDER MODERN CONDITIONS<a href="#FN1">¹</a>

Abstract

The main territories for the development of Late Pleistocene loess are located in the inland regions of the Northern Hemisphere, so the very existence of loess in New Zealand, a region with a temperate maritime climate, is of undoubted scientific interest. The analysis of geological, geomorphological, paleogeographical and geochronological data on the distribution, structure and formation conditions of loess in New Zealand in the Late Pleistocene has been carried out. The study showed that in New Zealand, as in other regions of the temperate latitudes of the Southern Hemisphere, the accumulation of loess occurred mainly in the cold phases of the last climatic macrocycle: in the Early Pleniglacial, 80 (75)–(60) 55 ka BP; (2) during cooling within MIS 3, 45–40 ka BP on the South Island and 40–30 ka BP, with a peak of about 30 ka BP, on the North Island; (3) in the Late Pleniglacial, from 25 to 17–12 cal ka BP. Comparison of these stages with the Antarctica ice cores data shows their close relationship with global climate change. The article reviews data on the current conditions for the development of eolian processes and the formation of loess-like deposits in New Zealand. In contemporary conditions, eolian processes in New Zealand are concentrated within geomorphologically active territories, e. g. in river valleys with glacier feeding and an abundance of loose sediments, in areas with widespread coastal sand dunes, and in those territories where vegetation and soil disturbances promote wind erosion of the surface layers of unconsolidated sediments. Large-scale anthropogenic impact (destruction of forests, disruption of the herbaceous cover due to intensive grazing of livestock, especially sheep, ploughing of slopes on light weakly cohesive soils, etc.) to some extent makes the present interglacial conditions for the development of eolian processes in New Zealand similar to periglacial ones.