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16 December 2009

The Prehistoric Nusantara

Prehistoric Nusantara consists of a very long period, beginning somewhat 1.7 millions years ago. Our knowledge about this information is based on findings of human (hominid) and animal remains and fossils and other ancient evidences. Nusantara has been a very interesting region to discuss because of its strategic figure. From east to south of this archipelago, lies a meeting point between two massive continental flanks: Eurasia and Indo-Australia. At this point, the Eurasian flank moves southward and stabs into the bottom of the Indo-Australian flank, which moves northward. This movement has created a volcanic line along the Sumatra and Java islands, continued to Nusa Tenggara. It is therefore Nusantara has a high risk of volcanic earthquake. At the east point where two other massive continental flanks melt, Eurasia and Pacific, there is another line of volcanoes in Maluku islands in the north moving northward to Sulawesi island and the Philippines. Meanwhile, in the modern Nusantara western territory, which is estimated to emerge during Pleistosen era, the archipelago was once adjacent to the continental Asia. It is predicted that part of the archipelago belonged to the sea bed, namely Sundaland. This sea bed was parallel to what being so called Wallace Line. On the other hand, the east region of Nusantara was geographically part of Australian continent. Before having its modern name, Australia used to be Sahul land and part of Indo-Australia flank. Through its geological change, this continent was once part of Gondwana continent. In the end of Ice Age (20,000 to 10,000 years ago), earth temperature rose causing an extreme elevation of sea water surface. Most of the Sundaland was covered by ocean and created a group of new waters such as Malaka Strait, South China Sea, Karimata Strait, and Java Sea. During this period, Malaya Peninsula, Sumatera Island, Java Island, Kalimantan Island emerged together with other smaller islands and isles. From the east direction, Australian continent broke down giving birth to new islands and isles: Irian (Papua) and Aru. The sea water surface elevation had forced native people to separate and, in turn, inspired the birth of modern Nusantara. Geological history of Nusantara affects the flora and fauna living in this region, in particular human-like creatures that once inhabited the archipelago. Nusantara used to be a sea bed, like the southern coast of Java and Nusa Tenggara. It has been evidenced by the discovery of vary marine fossils in these two areas. Their fundamental materials consist of karts, which were made from ancient coral reef lime sediments. Coal sediments in Sumatera and Kalimantan indicates that these regions had forests during Paleozoikum era. The shallow seas between Sumatera and Java (including Bali), and between Java and Kalimantan, as well as Arafura Sea and Torres strait are young water territories which only emerged by the end of the last Ince Age (10,000 years before the modern era). There is similarity in animal and floral species between them. Human-like creatures (hominin) that lived in Nusantara are believed the anchestors of the modern Javaneses. The fossil of skull remains of Pithecanthropus erectus, discovered in 1891 by Eugene Dubois in Trinil Ngawi, proved this. In 1934, other geologist, GHR von Koenigswald led a team of excavation of hominin fossils in Sangiran and Ngandong, a valley along the river bank of Bengawan Solo, and in Brantas riverbank nearby Mojokerto. Most paleonthologists argue that the whole fossils discovered are actually Homo erectus in its primitive form. The fossils were once estimated to be 1,000,000 to 500,000 years old (carbon measurement is impossible to perform).

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