Julian Richards has suggested that one reason that sarsens were removed was for the stone to be used for producing grinding querns. There is very little stone in neighborhood suitable for stones to grind grain with and some sarsen stone types are very suitable, other less so. So a source of excellent source material may have been irresistible in the later Bronze Age, and a quern manufactory set up.
"East of (north Fargo) plantation the field system corresponds with an area of later Bronze Age activity identified by extensive surface collection in the winter of 1980-81 and subsequently sampled more intensively (Richards, J 1990 The Stonehenge Environs Project. HBMC: London ). The surface scatter consisted of pottery and large quantities of burnt flint and burnt and broken sarsen, including quern fragments, and was interpreted as a small nucleated area of later Bronze Age settlement, lying within the area of regular field"
Research Department Report Series 82-2011
STONEHENGE WORLD HERITAGE SITE
LEVEL 1 FIELD INVESTIGATIONS
ARCHAEOLOGICAL SURVEY REPORT