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Mighty rivers and resources

Kalimantan is bordered by the Sulawesi Sea in the northeast, due south this is Selat Makassar (Makassar Strait). South of the island is the Jawa Sea. The South China Sea separated Kalimantan from mainland Southeastern Asia. Kalimantan doesn't have any good harbours; big parts of the island are barely above sealevel, and the tides influences the hight of the rivers far inland.
Borneo came above the sealevel a few milion yeras ago. By the sometimes high and low water levels during and between the Ice Ages, the island was regularly flooded or dry, and then it was one big island with Jawa and Sumatera and the peninsula Malaysia. Still there are remains of big rivers on the ocean floor which flowed from the mountains in Sumatera and Malaysia to Borneo, the lowest point. On the climax of the last Ice Age, the waterlevel dropped about 150 meters. Borneo and Sulawesi were no more than 40 km from eachother. When the climate warmed up again the ice melted and the sealevel rose; all life moved to the inlands. Now there are identical freshwater fish on Sumatera and Borneo, but they can't be found on Sulawesi.

Mountains and rivers

Because of movements in sedimentary rocklayers during the Ice Ages the highest mountain ranges were formed in the inlands. The highest is roughly located in a north-south line from Sabah to the heart of Borneo, where it splits. Most peaks are lower than 1500 meters, but the black-granite Kinabalu in Sabah with it's 4100 meters is the highest point in Southeastern Asia. In West-Kalimantan are the remarkable, almost vertical, limestone formations. Because of the rough and spooky look, the population thinks that spirits house here. The Mulu is the highest point in Sarawak with 2377 meters.

Picture: Jungle river

From the central mountain range, rivers run to the sea into every direction. Along the shores of these rivers with heavy traffic, trade is concentrated. The biggest part of the population lives here. Most rivers can be entered from the sea until the rapids which are the border with the highlands. These rapids often have to be passed over land. Beyond that, the rivers are usually accessible again for transport. The rapids used to offer protection against the headhunters from the coastal areas; now they raise the price of petrol and trade goods in the hinterlands drastically.
In the north, the rivers are only slowed down by the very small coastal area. The most wide part is place for the biggest rivers: de Mahakam which runs towards the east, and the Kapuas - the longest river of Indonesia - which streams towards the west. In the south there are dozens of rivers which linger through the endless lowlands.

Rich natural resources

Borneo has a rich environment with natural resources, of which many are untouched as yet. In the neighborhood of Banjarmasin, diamont is mined in primitive mining shafts. The diamonts are also split, cut and polished in the same old-fashioned way. The diamont harvest, which made Borneo known in the West, was followed by the Chinese gold rush on the alluvial siltlayers of Kaltim. The most important gold deposits are in the earliest deposits in the mountains. Due to erosion, the rock was formed into gold clay, which is taken downstream by rain. Locals sift the silt for the smallest grind of gold. Hard labour pays, because the gold is almost as pure as you can get, 23 or 24 carat. Nowadays gold mining is an international business.
At the end of the 19th century, coal was mined on a large scale, followed by the raise of the oil-industry; Eastern Kalimantan has been an oil-producer ever since the beginning of the 20th century and the small oil-state of Brunei along the northern coast has the highest income per head of the population in the world.
Recently, uranium was discovered in Kalimantan. The indonesian treasury was funded by the export of LNG (liquid natural gas) to Japanese power producers.

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