Mountain Ranges, Deserts and Landforms of Indonesia

Geography

The Central Cordillera, some peaks of which are capped with ice, consists of (from east to west): the Central Highlands and Eastern Highlands of Papua New Guinea including the Owen Stanley Range in the southeast, whose highest peak is Mount Victoria at 4,038 metres (13,248 feet), the Albert Victor Mountains, the Sir Arthur Gordon Range, and the Bismarck Range, whose highest peak is Mount Wilhelm at 4,509 metres (14,793 feet), which is an extinct volcano with a crater lake; the Star Mountains on the Papua New Guinea–Indonesia border; and the Maoke Mountains or Snow Range in Indonesia, where perpetual snow was found by H. A. Lorentz in 1909 at 4,461 m (14,635 ft), and whose highest peaks are Puncak Jaya (Mt. Carstensz) at 4,884 m (16,024 feet), Puncak Mandala (Mt. Juliana) at 4,760 m (15,610 ft) and Puncak Trikora (Mt. Wilhelmina) at 4,750 m (15,580 ft).

Geology

This chain of mountains continues to rise (with corresponding quakes) as the Australian Plate collides with the plates to the northeast, marking the southern boundaries of the Maoke and Woodlark plates. The width of the mountain range varies considerably, with a central thin segment near the borders of the two nations.

The surface geology of the highlands is made up of metamorphic and intrusive igneous rocks. The metamorphic rocks were Cretaceous and Eocene ocean sediments that were uplifted and folded between the Eocene and early Miocene periods. There are also Pleistocene stratovolcanoes in the highlands, including Mount Hagen and Mount Giluwe.

Ecology

The New Guinea Highlands are home to a great variety of Australasian plant and animal communities, distinct from the surrounding lowlands to the north and south of the central ranges and varying up and along the mountain ranges. The habitats of the mountains have been separated into two ecoregions, depending on their elevation, the tropical montane forests and alpine grasslands, but within these broad bands there is a variety of wildlife along the island as some of the mountains stand quite a distance from others with some species of plant or animal existing on only one or two mountains.

History

The fertile Highlands have long been inhabited and artifacts uncovered in the Ivane Valley indicate that the Highlands were first settled about 50,000 years ago. The inhabitants were nomadic foragers but around 10,000 years ago began developing a fairly advanced agricultural society. Before the introduction of the sweet potato, the Highlands had distinct forms of division of labor. In the Eastern Highlands the economy was mixed, with men hunting and cultivating, and women gathering and tending crops. Populations were small, dispersed, and focused on immediate consumption.