A company which wants to quarry near an ancient monument has dismissed suggestions that the site contains items of archaeological importance.
The northern henge is covered with trees but others are clearly visible
Tarmac wants to extend its sand and gravel operations near Thornborough Henges close to Ripon, North Yorks.
Residents fear further quarrying could destroy clues about why the 5,000-year-old earthworks were built.
But archaeologists working for Tarmac say there is only "thin and scattered" evidence of prehistoric activity.
Tarmac commissioned York-based Mike Griffiths and Associates (MGA) to carry out a survey as part of its application to the county council to extend its present quarry at Nosterfield.
The henges are in open countryside near the A1
The new site at Ladybridge Farm, like Nosterfield, is near the henges which consist of three earthworks built in a line running north-south for about a mile.
Each henge consists of circular earth banks and ditches which may have been covered with gypsum.
Archaeologist Steve Timms from MGA said: "With the exception of just seven shallow pits which contained Neolithic finds, very little else has been found.
"Apart from two fragments of pottery we have no evidence for Roman or medieval activity at all and most of the prehistoric finds were collected from the surface of the fields during the field walking
"The evidence suggests that people were doing something on the site in the Neolithic period but there is not enough evidence to say what it was."
North Yorkshire County Council is due to consider the application to extend the quarry later in the year.
Mike Sanders from Friends of Thornborough Henges said the MGA survey was "quite inadequate".
"Less than 2% of the Ladybridge Farm site has been surveyed," he claimed.
Mr Sanders added that advances in archaeological techniques in future years might turn up more evidence and destroying the landscape now meant that opportunity would be lost.