Stonehenge and its Altar Stone: the significance of distant stone sources

Stonehenge and its Altar Stone: the significance of distant stone sources

Abstract

Geological research reveals that Stonehenge's stones come from sources beyond Salisbury Plain, as recently demonstrated by the Altar Stone's origins in northern Scotland more than 700 km away. Even Stonehenge's huge sarsen stones come from 24 km to the north, while the bluestones can be sourced to the region of the Preseli Hills some 225 km away in west Wales. The six-tonne Altar Stone is of Old Red Sandstone from the Orcadian Basin, an area that extends from the Northern Isles of Orkney and Shetland to Inverness and eastwards to Banff,

Turriff and Rhynie. Its geochemical composition does not match that of rocks in the Northern Isles, so it can be identified as coming from the Scottish mainland. Its position at Stonehenge as a recumbent stone within the southwest arc of the monument, at the foot of the two tallest uprights of the Great Trilithon, recalls the plans of recumbent stone circles of north-east Scotland. Unusually strong similarities in house floor layouts between Late Neolithic houses in Orkney and the Durrington Walls settlement near Stonehenge also provide evidence of close connections between Salisbury Plain and northern Scotland. Such connections may be best explained through Stonehenge's construction as a monument of island-wide unification, embodied in part through the distant and diverse origins of its stones.

Introduction

The megalithic monuments of Neolithic and Chalcolithic Europe required considerable collective effort not only for their erection but also for the movement of their stones from source to monument. In the vast majority of cases, these stones were moved only short distances of less than ten kilometers or so. Even so, the weights of some megalithic stones such as the almost one hundred fifty-tonne capstone of the Menga tomb at Antequera in southern Spain and the three hundred thirty-tonne Grand Menhir Brisé in Brittany, France mean that movement of these huge stones even over relatively short distances of a kilometer or more from their sources was still an extraordinary achievement.

Stonehenge is unique among megalithic stone circles for several reasons: the raising of lintels on top of uprights, the extensive stone-dressing of its surfaces, and - most significantly - the non-local origins of its stones. Yet it was not the first Neolithic monument with raw materials sourced at a distance. Beginning before the end of the fourth millennium calendar BC, there is a trend of composite monumentality in which megalithic tombs were built of materials from different sources.

The great passage tombs of Newgrange and Knowth in Brú na Bóinne were constructed with stones brought from at least six source areas as far away as forty kilometers to the north and south along Ireland's east coast. The largest of these weigh around half a tonne - the greywacke blocks brought from up to five kilometers away.

The great passage tomb of La Hougue Bie, Jersey, incorporates different rocks from across the island. Apart from passage tombs, stone circles and other monuments at this time were also composed of different types of rock, although the distances travelled were substantially less. The two Orcadian stone circles, the Ring of Brodgar and Stones of Stenness incorporate monoliths derived from up to seven sources, covering distances of more than thirteen kilometers. Also, different stone circles among the complex on Machrie Moor, Arran, are constituted of different types of rock: red sandstone and white granite, both derived from different places on the island.