NEW technology is being used to unearth the secrets of ancient stone carvings.

It is hoped the high-precision laser technology will allow archaeologists to examine in detail the methods used to create the carvings.

Five rocks with Stone Age engravings in Teesdale, County Durham, are being recorded using three-dimensional laser scanning in the North-umberland and Durham Rock Art project.

Laser scanning has been used in the past for engineering purposes, but has only recently started to be used to record ancient monuments such as Stonehenge.

Only a handful of ancient carvings have been recorded with this method, and it is the largest number of carved pieces scanned by one project.

It involves sending a laser beam across the rock, which records changes in the surface of up to 0.2mm.

They are recorded as digital data, which can be used to create a three-dimensional reconstruction of the rock surface and carvings.

This image can then be manipulated and even used to create a scale model made from high-density polyure-thane.

This can then be used in schools and museums.

Rock Art project officer Tertia Barnett said the laser scanning would allow archaeologists to record how much the rock carvings had been eroded or damaged, and would not damage the surface.

She said: "It records every single grain and can even pick up the marks made by the tools, so we can learn a lot about it.

"Nobody really knows what the carvings were for. There are lots of theories and everyone has got their favourite, from space aliens to tribal rituals.

"The majority of people think they are something to do with marking out the landscape.

"They are very much a Northern thing, which is partly why they have been overlooked in the past.

"The North does tend to take a back seat in archaeological circles and it tends to get bypassed, so we have to do a lot of raising awareness nationally."

The rock art, some of which dates from 5000BC, consists of cup-shaped hollows, concentric rings and other patterns and there are more than 1,000 examples in Durham and Northumberland.

Officials from the project, which is funded by English Heritage and co-ordinated by Durham and Northumberland County Councils, hope to compile a complete record of all the North's rock art.