The Mountains of the South-Temperate, Austral and Antarctic Regions

Abstract

The principal elevated areas, of entomological interest, in the south-temperate and antarctic regions arc the mountains of Australia, New Zealand, Tasmania, the Chilean Andes, the Patagonian Steppes, the Andes of Tierra del Fuego and the mountains of Antarctica. Although parts of the high regions of northern Australia are really within the torrid zone, a number of considerations justify discussion of all the Australian mountains as part of the south temperate region. The Andes south of Bolivia, in other words the Chilean Andes, the Argentinian Andes, the Patagonian Andes and the Patagonian Steppes and the southernmost parts of the Andes in Tierra del Fuego constitute perhaps the most remarkable high altitude regions of the southtemperatre and sub-antarctic areas. As mentioned elsewhere, the main trendline of the Andes in Tierra del Fuego is almost east-west. It has recently been shown that Tierra del Fuego and Patagonia are geographically closely related. Besides the Andes, we must also consider the area of the Mesetas to the east of the Andes. As the predominant winds are westerly, the rainfall and dense forests are concentrated on the Andes; the Mesetas and the plains are typically steppes and semi-deserts. The area closest to the Andes was covered by ice during the late Pleistocene. Old glacial moraines, east of the limits of the youngest glaciation, are correlated with the penultimate glaciation that corresponds probably with the Wurm Glaciation in the northern hemisphere. Among the more important high mountain peaks, situated within the south temperate region, are Llullaillaco (25° SL and 6720 metres above mean sea-level), Ojos del Salado (27° SL and 6870 metres), Mercedario (32° SL and 6765 metres) in Argentina-Chile; and Aconcagua in Argentina (32° 30′ SL and 7034 metres).