This shows that the Lhasa area was not a vast expense of water some 110 million years ago as has previously been thought, geologists said.

The silicified wood, including tree trunks and roots, were found in the geological stratum of the Cretaceous period in Deqingtown in suburban Lhasa.

The tree trunk has a diameter of 50 centimeters and was well preserved, according to geologists with the regional geological department.

Geologists said the discovery was of great significance in studying the change from sea to land, and the ancient climate in the area.

Previously, only clastic rock, calcium shale and siltstone werefound in the area, and from the rocks, shale and siltstone, geologists discovered fossils of sea urchins, ammonite, bivalves and other sea creatures.

Geologists have also discovered fern fossils in the area, but it was the first time that that silicified wood was found.