Antoni Judit: „Ablakok Pápua Új-Guineára" (Távoli világok emberközelben II. Gödöllői Városi Múzeum, 2008)

Sahul Shelf formed a link between Australia, New Guinea and the Aru islands. The 40 km wide and 1800 m deep Makassar Strait made traffic impossible, and it was the main cause of detachment between the faunas of Asian and Australian origin. Due to the general cooling of our planet, however, ice accumulated in the northern hemisphere, and - as a result - the sea level decreased to such an extent that dry areas started to emerge between the two shelves, opening up a passageway for the first people to cross on foot and by boat. The first inhabitants of New Guinea arrived about 4050,000 years ago, in part from Southeast Asia: they settled in the western-most part of the island, and in the coastal region. Others probably migrated north from what is now Australia (which was by then already populated). The first migrants to New Guinea and Australia are likely to have been anthropologically similar to each other, and the languages of the Australian aborigines show some structural similarities with the languages of the peoples of the Highlands of New Guinea. The island took its present-day aspect 11,000 years ago, when a general warming followed the end of the ice age and the dry areas were again inundated by the sea, detaching New Guinea from Australia despite their sharing of the same continental shelf. New Guinea lies along the border of two tectonic plates. The Australian continental plate slowly drifts northward, while the Pacific plate moves westward. The surface of the island -situated in the collision zone of the two-is formed, even today, by geological events related to this movement. The central mountain chain is actually the one-time sea bottom, covered with sediment, which was creased into folds and forced up to a height of 4-5,000 m by the effect of tectonic forces operating at the boundary of the two plates. The Sepik-Ramu region was, until 6,000 years ago, a bay with an average depth of 200 m. It owes its present-day aspect to the fact that, after the rise of the sea level at the end of the Pleistocene, or ice age, the mainland also started to lift, and the Sepik and Ramu rivers accumulated increasingly high sediment deposits. This sediment (reaching a depth of 8 m at some places) converted the inland sea, which had until then nurtured deep-sea organisms, into a fresh-water marshland. Island-like hills and mountains (the Aibom and Chambri mountains, and the Bosmun plateau) extending to a length of nearly 250 km and a depth of 100 km along the coastline are reminders of this vanished world. 26,000 year old sea- and fresh-water snail shells have been found in marine mud in the bank of the Djom river: this site is today in the interior of the island, 100 km from the point at which the river Ramu flows into the sea. The fragment of a Homo sapiens skull found here testifies that men settled here fairly early - about 5,000 years ago. Thanks to archaeological research done in the 1980s, several sites have been excavated in this region. In the middle reaches of the Sepik, people settled in the rock cavity at Kowekau, near Timbunke, 14,000 years ago, and we know that their descendants were making pottery by about 6,000 years ago. Flint and polished stone instruments dating back 3,000 years have been found in several places, and an axe-blade made of scallop shell found at the upper reaches of the Sepik (Frieda Airstrip, East Sepik Province) is nearly 5,000 years old. The earliest archaeological evidence of the people living near Lumi, on the southern side of the Torricelli Mountains (part of the chains running parallel with the seashore) is a 15 cm long tanged stone blade. It is thought to date from the Pleistocene, and was given to the National Museum of Papua New Guinea by Emese Molnár-Bagley sometime between 1982 and 1988. The island and its peoples underwent several external impacts of varying degrees, beginning with the stilldiscussed Japanese neolithic contact. The island then found itself in the migratory passageway of the Austronese (or Malay-Polynesian) peoples, which introduced a host of new anthropological, linguistic and cultural elements. Finally, the sea merchants of Southeast Asia, from Indonesia and the Philippine Islands, appeared in the bronze age. The coastal region and the Sepik River Basin: the natural environment The climate of the region is controlled by two air current systems: the southeasterly trade winds blow during the dry season (from April to October), when the rivers irrigate different areas in turn. Then, during the rainy season, at the time of the stormy northwesterly monsoon period (from November to March), the rivers 130