It comes after the discovery of a large amount of silicified wood - wood converted into or impregnated with silicon dioxide - in areas around the city, meaning it was probably a tropical rain forest about 2.5 million years ago.

Geologists from Hubei University located five sections of silicified wood in the city's Xinzhou District.

The largest is 3.3 metres in length and has a diameter of 1.3 metres. The smallest has a diameter of 0.9 metres and bole length of over 3 metres.

Hubei University Geology Department Associate Professor Qi Guofan said he and his colleagues came across a 2.1-metre-long piece of silicified wood with a diameter of 0.5 metres by the side of the road near Xinzhou in 1984, the first to be found in Wuhan.

Qi said experts from the Chinese Academy of Forestry Sciences confirmed the wood evolved from ancient camphor-wood, the first example of silicified camphor-wood discovered in the world.

Qi has collected more than 300 pieces of silicified wood over the past 20 years. He said his discoveries were divided into more than 20 categories, belonging to 13 ancient plant species.

The geologist said Wuhan and areas along the lower reaches of the Yangtze River, the longest river in China, enjoyed higher temperatures 2.5 million years ago and were much more moist than at present, citing the fact that all of the silicified woods belonged to tropical and sub-tropical species.

He said the discovery of fossils of angiosperm, in particular, was of significant importance in the study of ancient plants.

(China Daily November 20, 2002)