Preseli Dolerite Bluestones: Axe‐heads, Stonehenge Monoliths, and Outcrop Sources

Abstract

Chemical compositions and magnetic susceptibility data were compared for 12 dolerite bluestone implements including axes, axe-hammers and battle-axes, 11 Stonehenge monoliths (chemical data only), and potential source outcrops in Preseli, South Wales. Most of the studied artefacts are of spotted dolerite, a small number being unspotted dolerite. Bivariate graphs, discriminant analysis and t-tests were used singly and in combination to show, respectively, that the implements found at sites in England are mainly similar to Stonehenge monoliths, while the implements found in Wales have a variety of compositions and are much less similar to Stonehenge monoliths. The dichotomy between English and Welsh dolerite bluestone implements could be explained by exploitation of different Preseli outcrops or erratic assemblages derived from them. A small number of spotted dolerite implements have previously been shown to have chemical compositions atypical of and marginal to Preseli, suggesting the possibility of a source of spotted dolerite outside Preseli. Previously published analytical data in combination with the new implement/outcrop comparisons presented in this paper support derivation of the majority of analysed Stonehenge monoliths at one particular outcrop within the group of four identified by Thorpe et al. 15 years ago. Analysis of all the extant bluestone monoliths at Stonehenge (now possible using non-destructive methods) would allow progress in identifying monolith outcrop sources, and in understanding the links with the bluestone axe trade. introduction and backgroundArchaeological 'bluestone' studies have traditionally focused on the stones used for the Stonehenge monoliths, but more recently attention has turned to the polished axe-heads and other implements manufactured from bluestone (Williams-Thorpe et al. 1999;Jones and Williams-Thorpe 2001;Williams-Thorpe et al. 2004).In this paper, we bring together information on the sources of dolerite bluestone implements, and of the Stonehenge monoliths, in order to comment on the relationship between these two groups of artefacts. In particular, we examine the question of whether the monoliths and the implements originated at the same sources within Preseli, and what this tells us about the links between the procurement of bluestone for Stonehenge, and the bluestone employed in England and Wales for implements. 29Recent non-destructive geochemical and magnetic studies of spotted dolerite implements (including axes, axe-hammers, battle-axes and maces) showed that fewer than a dozen can be reliably assigned to the Preseli source area (Williams- Thorpe et al. 2004). That work resulted in a revised, and much reduced, distribution of these implements (which are also referred to as 'Group XIII', following the terminology of the British Implement Petrology Committee (IPC); Clough and Cummins (1988)).Within the dataset for the implements confirmed as Preseli by Williams-Thorpe et al. (op. cit.), there appeared to be small variations in chemical and magnetic characteristic...

Characterization and provenance of the slabs of the Puigseslloses Megalith, Barcelona, Spain

“…In the study made by Atkinson, it was proposed that the sandstone blocks, reaching up to 50 t in weight, had been transported from areas 50 km to the north of the megalithic monument, while the blocks made from "blue sandstone" (which, in fact, is igneous rock, essentially dolerites), of up to 4 t, had been transported from the Preseli Hills in southeast Wales, that is, 240 km in a straight line from the site of the monument (Atkinson, 1979). Further hypotheses on the transport distance are found (among others) in Green (1997), Scourse (1997), Thorpe and Williams-Thorpe (1991), Williams- , and Williams- Thorpe, Jones, and Webb (2006). In any case, all studies state that the building of Stonehenge meant a large work investment in terms of stone block supply.…”

Stonehenge rhyolitic bluestone sources and the application of zircon chemistry as a new tool for provenancing rhyolitic lithics

“…This source was verified in the comprehensive study by Thorpe et al (1991), which presented geochemical analyses of the Stonehenge bluestone lithologies, including not only the spotted but also the un-spotted dolerites, drawing comparisons with the data set for north Pembrokeshire dolerites compiled by Bevins et al (1989). The Thorpe study determined the source of the spotted dolerites to a small number of specific outcrops in the Mynydd Preseli district, findings which were supported in subsequent investigations by Ixer (1994Ixer ( , 1996Ixer ( , 1997 and Williams- Thorpe et al (2006).…”

Leonardo García Sanjuán, Chris Scarre and David W. Wheatley, eds. Exploring Time and Matter in Prehistoric Monuments: Absolute Chronology and Rare Rocks in European Megaliths (Proceedings of the 2nd European Megalithic Studies Group Meeting, Seville, Spain, November 2008, Menga: Journal of Andalusian Prehistory Monograph No. 1, Seville: Andalusian Government, 2011, 387pp., many illustrations including colour plates, hbk and CD, ISBN 978-9959-083-7)

“…11). La dolerita moteada también fue usada en un número muy reducido de útiles de piedra del Neolítico y de la Edad de Bronce Inicial (Williams- Thorpe et al, 2006). Estos doce hallazgos incluyen cuatro hachas, una maza, tres hachas de combate y dos hachas-martillo.…”

“…A pesar de ello, las evidencias son débiles y quedan cuestiones más amplias por resolver: ¿por qué, por ejemplo, la dolerita moteada galesa no se comercializó y dispersó más ampliamente por Britania en el Neolítico? Únicamente se han encontrado 12 artefactos prehistóricos portables realizados con esta roca (Williams- Thorpe et al, 2006.) Podría ser de esperar que las piedras con propiedades curativas hubieran sido demandadas, ansiadas por gentes muy diferentes y en muchos sitios diferentes de Gran Bretaña; ¿por qué limitar su distribución fuera de Preseli sólo en Stonehenge y en Bluestonehenge?…”