There have been many theories for tektite origins, with a lunar origin (rock splashed out from the moon by meteorite impact, or erupted from volcanoes) being dismissed only recently. The most favoured theory suggests an origin from Earth, where rock was hurled up into our atmosphere by the impact of a large meteorite or asteroid, then partially re-melted as it fell back through the atmosphere to the ground.
In this theory's favour is the chemical similarity between some Earth rocks and tektites, and the composition of gas bubbles in Moldavites. The gas in these bubbles was under very low pressure, equivalent to 32 km altitude in our atmosphere.
A number of impact craters on Earth have been suggested as sources of tektites. The Ries Crater in southern Germany has shock effects extending down to over 2 km, and may be linked to Moldavites, while the Lake Bosumtwi Crater, Ghana may be linked to Ivory Coast tektites. A large crater in Western Cambodia (Lake Tonle Sap) is one of the possible sources of Australasian south-east Asian tektites. Sources for some strewn fields, like the North American one, are still unknown and are perhaps hidden by dense jungle, covered by seas or are difficult to recognise because of heavy erosion.
Copyright © Australian Museum, 2004