In 1908 on Siberia there was mysterious disaster. Some object, called the "Tunguska meteorite", fall from the sky causing distruction of wide area of Taiga forest. First expedition was there 20 years later but since then no crater was found what is very strange. According to one of the most known theories, the crater could be known today as lake Cheko.
In 1994 the Italian geologists proposed hypothesis that lake Cheko in the Krasnoyarsk region is the actual crater of the Tunguska meteorite. However, new research done by Russian scientists claim the opposite.
Specialists from Novosibirsk and Krasnoyarsk with the help of modern radioisotope methods, have determined that the age of the deepest sediments of the lake that were studied, reaches 280 years. And this is obviously not the limit, as the layers go on and on to unknown depth. This prooves that it was formed much earlier and can not be related to Tunguska event.