By: Alice Baghdjian
LONDON (REUTERS).- An early prehistoric hearth has been discovered on the planned construction site for a branch of major British supermarket chain Sainsbury's.

The charcoal remains, excavated from the site in Nairn, a town in the Scottish Highlands, date back to the Mesolithic period (10,000 to 4000 BC). They are believed to have been a temporary traveling stop rather than a settlement, due to the absence of any further Mesolithic findings at the site.

"An extremely large quantity of wood charcoal fragments was recovered from the hearth. The size of the fragments suggests either deliberate deposition or in-situ burning," said Headland Archaeology, who carried out the excavation, in a report.

Archaeologists used carbon-dating of the charcoal to determine the age of the hearth. However, dating a site from this particular substance is problematic, due the potential time lag between the felling of the tree and the burning of the material, the report said.

The excavation, commissioned by British retailer J Sainsbury Plc, was carried out in advance of construction. The development is continuing as planned after no further excavation was deemed necessary.

"Mesolithic sites do come up occasionally. The hearth was excavated and dated, and no secondary excavation was needed," said Kirsty Cameron at the Highland Council Historic Environment Record (HER), which logs the discovery of all known historic and archaeological sites in the Highland Council area.

At least 175 sites with a Mesolithic background are registered on HER's online database. Activity during the Mesolithic period has already been discovered in the area after the identification of several small flint tools at Culbin Sands, on the Moray Firth coastline near Nairn.

During the Mesolithic period, or Middle Stone Age, the Britain was populated by nomadic hunter-gatherers. It is believed they lived in family groups and traveled across land, and possibly waterways, in order to hunt and fish.

(Edited by Paul Casciato)