Geology

There are three areas in the world where there are very ancient rocks that have not been re-absorbed back into the earth as continental plates moved. Parts of Greenland, a piece of Australia and the western region of Swaziland/ Barberton known as the Greenstone Belt. The Earth is believed to be some 4.6 billion years old and the ancient rocks in the Greenstone belt are dated to 3.6 billion years. Naturally each of the three regions has experts who provide evidence that theirs is definitely the most ancient, but there is general agreement that the oldest crust, a form of degraded gneiss, is in the Greenstone Belt and that very likely the oldest single celled life forms have left fossilised remains as well in chert. These ancient rocks are well preserved in Malolotja Nature Reserve, an area of dramatic mountainous scenery.

The reserve also has the wolrd''s oldest mine, carbon dated to some 42 000 years ago. The miners were looking for haematite and specularite, red rust and iron glitter respectively. The Greenstone Belt also has traces of gold, large depsits of iron and some asbestos, in fact almost all of the contry''s economically important minerals occur there.

There are vast deposits of low grade coal underlying much of the lowveld and one diamond pipe. Much of the western part of the country that lies outside the Greenstone Belt is granite, and there are large domes of granite throughout the highveld. One of them, Sibebe, is believed to be the largest pluton in the world. The lowveld is a mixture of rocks, but the basement rock in the country is gniess , there are large area of basalt that have resulted in very rich soil that is used to grow sugar, the country''s main export.

The eastern boundary is a rhyolite and basalt mountain range, the Lubombo. This formed some 180 million years ago when the ancient supercontinent of Gondwanaland first began to crack before breaking up and separating into the continets that we know today. At that time the hard rhyolite filled the crack, the softer surrounding rock eroded away over millions of years and left a blue-grey mountain range.

The photo shows a deep gorge in the Greenstone belt.