This paper examines the hypothesis that Waun Mawn in West Wales provided the bluestone monoliths that were used at Stonehenge. Some archaeologists believe that the site supports the last remains of a ...giant stone circle or ‘Proto Stonehenge’ which was dismantled and transported to Salisbury Plain around 5000 years ago. It was claimed, after three excavation seasons at Waun Mawn in 2017, 2018 and 2021, that there is firm evidence of some standing stones which were later removed or broken up, but it has still not been demonstrated that there ever was a small stone circle here, let alone a ‘giant’ one. Furthermore, there have been no control studies in the neighbourhood which might demonstrate that the speculative feature has any unique characteristics. There is nothing at Waun Mawn to link this site in any way to Stonehenge, and this is confirmed by recent cited research. No evidence has been brought forward in support of the claim that ‘this was one of the great religious and political centres of Neolithic Britain’. It is concluded that at Waun Mawn and elsewhere in West Wales there has been substantial ‘interpretative inflation’ driven by the desire to demonstrate a Stonehenge connection.
A Neolithic stone circle at Waun Mawn, in the Mynydd Preseli, west Wales, has been proposed as the original location of some dolerite megaliths at Stonehenge, including one known as Stone 62. To ...investigate this hypothesis, in-situ analyses, using a portable XRF, have been obtained for four extant non-spotted doleritic monoliths at Waun Mawn, along with two weathered doleritic fragments from a stonehole (number 91). The data obtained have been compared to data from spotted and non-spotted dolerite outcrops across the Mynydd Preseli, an area known to be the source of some Stonehenge doleritic bluestones, as well as data from in-situ analysis of Stone 62 (non-spotted dolerite) and ex-situ analysis of a core taken from Stone 62 in the late 1980′s.
Recently, Stone 62 has been identified as coming from Garn Ddu Fach, an outcrop some 6.79 km to the east-southeast of Waun Mawn. None of the four dolerite monoliths at Waun Mawn have compositions which match Stonehenge Stone 62, and neither do the weathered fragments from stonehole 91. Rather the data show that the Waun Mawn monoliths, and most probably the weathered stonehole fragments, can be sourced to Cerrig Lladron, 2.37 km southwest of Waun Mawn, suggesting that a very local stone source was used in construction of the Waun Mawn stone circle. It is noted that there is evidence that at least eight stones had been erected and subsequently removed from the Waun Mawn circle but probability analysis suggests strongly that the missing stones were also derived, at least largely, from Cerrig Lladron.
•Portable XRF, widely used in archaeological provenancing, is unsuitable for use with excavated lithic artefacts without mechanical abrasion of the artefact surfaces prior to analysis.•ICP-MS ...analysis remains a robust tool for geochemical provenancing of excavated lithic artefacts, providing the samples are sufficiently large.•Geochemical analysis indicates that large sarsen boulders used in the construction of Stonehenge were sourced from at least two different locations in the Marlborough Downs.•Sarsen of undetermined use was brought to Stonehenge from several different areas, two of which include Bramdean, Hampshire (51 km from the monument) and Stoney Wish, East Sussex (123 km from the monument).
The application of novel geochemical provenancing techniques has changed our understanding of the construction of Stonehenge, by identifying West Woods on the Marlborough Downs as the likely source area for the majority of the extant sarsen megaliths at the monument. In this study, we apply the same techniques to saccharoid sarsen fragments from three excavations within and outwith the main Sarsen Circle to expand our understanding of the provenance of sarsen debitage present at the monument. Through pXRF analysis, we demonstrate that the surface geochemistry of 1,028 excavated sarsen fragments is significantly affected by subsurface weathering following burial in a way that cannot be overcome by simple cleaning. However, we show that this effect is surficial and does not have a volumetrically significant impact, thus permitting the subsequent use of whole-rock analytical methods. Comparison of ICP-AES and ICP-MS trace element data from 54 representative sarsen fragments with equivalent data from Stone 58 at Stonehenge demonstrates that none are debitage produced during the dressing of this megalith or its 49 chemical equivalents at the monument. Further inspection of the ICP-MS data reveals that 22 of these fragments fall into three distinct geochemical ‘families’. None of these families overlap with the geochemical signature of Stone 58 and its chemical equivalents, implying that sarsen imported from at least a further three locations (in addition to West Woods) is present at Stonehenge.
Comparison of immobile trace element signatures from the 54 excavated sarsen fragments against equivalent data for 20 sarsen outcrop areas across southern Britain shows that 15 of the fragments can be linked to specific localities. Eleven of these were likely sourced from Monkton Down, Totterdown Wood and West Woods on the Marlborough Downs (25–33 km north of Stonehenge). Three fragments likely came from Bramdean, Hampshire (51 km southeast of Stonehenge), and one from Stoney Wish, East Sussex (123 km to the southeast). Technological analysis and refitting shows that one of the fragments sourced from Monkton Down was part of a 25.7 cm × 17.9 cm flake removed from the outer surface of a large sarsen boulder, most probably during on-site dressing. This adds a second likely source area for the sarsen megaliths at Stonehenge in addition to West Woods. At this stage, we can only speculate on why sarsen from such diverse sources is present at Stonehenge. We do not know whether the fragments analysed by ICP-MS were removed from (i) the outer surface of Stones 26 or 160 (which are chemically distinct to the other extant sarsen megaliths), (ii) one of the c.28 sarsen megaliths and lintels from the c.60 erected during Stage 2 of the construction of Stonehenge that may now be missing from the monument, or (iii) one of the dismantled and destroyed sarsen megaliths associated with Stage 1 of the monument. With the exception of the fragment sourced from Monkton Down, it is also possible that the analysed fragments were (iv) pieces of saccharoid sarsen hammerstones or their pre-forms, or (v) small blocks brought on-site for ceremonial or non-ceremonial purposes.
•Investigation was undertaken on a rock sample purported to have been collected from the underside of the Altar Stone (Stone 80) at Stonehenge in 1844.•The sample was analysed petrographically and by ...using portable XRF and automated SEM-EDS techniques.•Distinctive mineralogical and geochemical characteristics support the sample’s authenticity in terms of provenance.•The sample provides a ‘go-to’ proxy for future investigations of the Altar Stone.
Megalithic Stone 80 at Stonehenge, the so-called Altar Stone, is traditionally considered to be part of the bluestone assemblage, a diverse range of lithologies exotic to the Wiltshire Landscape. However, the Altar Stone, a grey-green micaceous sandstone, is anomalous when compared with the other (predominantly igneous) bluestones, in terms of its lithology, size and weight, and certainly in terms of its provenance. Recent investigations into the character of the Altar Stone have focussed on excavated fragments now attributed to be derived from the Altar Stone, as well as non-destructive portable XRF (pXRF) analysis on the Altar Stone itself (re-analysed as part of this investigation). In this study we have investigated a sample from the collections of Salisbury Museum, 2010K 240 (also referred to as Wilts 277), which bears a label recording that it was collected from the underside of the Altar Stone in 1844. We examined the sample petrographically and also by using pXRF and automated SEM-EDS techniques. Like the excavated fragments, this sample from the Altar Stone shows a distinctive mineralogy characterised by the presence of baryte and kaolinite along with abundant calcite cement. The presence of baryte leads to relatively high Ba being recorded during pXRF analysis (0.13 wt%). Combined, these results validate the history recorded on the specimen label and, as far as we know, makes this the only specimen taken purposely from that megalith. As such sample 2010K 240 provides a ‘go-to’ proxy for future studies of the Altar Stone as well as validating those samples recently assigned to the Altar Stone. In addition, this study demonstrates the vital importance of historic collection specimens and their preservation, conservation and documentation, as well as the role pXRF can play in the analysis of sensitive cultural artefacts and monuments that cannot be analysed using invasive or destructive techniques.
The Altar Stone at Stonehenge is a greenish sandstone thought to be of Late Silurian-Devonian (‘Old Red Sandstone’) age. It is classed as one of the bluestone lithologies which are considered to be ...exotic to the Salisbury Plain environ, most of which are derived from the Mynydd Preseli, in west Wales. However, no Old Red Sandstone rocks crop out in the Preseli; instead a source in the Lower Old Red Sandstone Cosheston Subgroup at Mill Bay to the south of the Preseli, has been proposed. More recently, on the basis of detailed petrography, a source for the Altar Stone much further to the east, towards the Wales-England border, has been suggested. Quantitative analyses presented here compare mineralogical data from proposed Stonehenge Altar Stone debris with samples from Milford Haven at Mill Bay, as well as with a second sandstone type found at Stonehenge which is Lower Palaeozoic in age. The Altar Stone samples have contrasting modal mineralogies to the other two sandstone types, especially in relation to the percentages of its calcite, kaolinite and barite cements. Further differences between the Altar Stone sandstone and the Cosheston Subgroup sandstone are seen when their contained zircons are compared, showing differing morphologies and U-Pb age dates having contrasting populations. These data confirm that Mill Bay is not the source of the Altar Stone with the abundance of kaolinite in the Altar Stone sample suggesting a source further east, towards the Wales-England border. The disassociation of the Altar Stone and Milford Haven undermines the hypothesis that the bluestones, including the Altar Stone, were transported from west Wales by sea up the Bristol Channel and adds further credence to a totally land-based route, possibly along a natural routeway leading from west Wales to the Severn estuary and beyond. This route may well have been significant in prehistory, raising the possibility that the Altar Stone was added en route to the assemblage of Preseli bluestones taken to Stonehenge around or shortly before 3000 BC. Recent strontium isotope analysis of human and animal bones from Stonehenge, dating to the beginning of its first construction stage around 3000 BC, are consistent with the suggestion of connectivity between this western region of Britain and Salisbury Plain.This study appears to be the first application of quantitative automated mineralogy in the provenancing of archaeological lithic material and highlights the potential value of automated mineralogy in archaeological provenancing investigations, especially when combined with complementary techniques, in the present case zircon age dating.
•Automated mineralogy is used for the first time in lithic provenancing.•Results are complemented by findings for U–Pb zircon age dating.•Results show that the Stonehenge Altar Stone is not derived from west Wales.•The findings undermine the theory that the Stonehenge bluestones were transported by sea.
•Portable XRF analysis was applied to provenancing the Stonehenge bluestones.•In situ analysis was undertaken on Stone 62 at Stonehenge and on key Preseli outcrops.•The source of Stone 62 is ...attributed to the Garn Ddu Fach Preseli outcrop.•A robust analytical strategy was developed and implemented to take into account a range of factors possibly expected to influence the analyses.
The doleritic bluestone monoliths at Stonehenge have long been known to have been sourced from the Mynydd Preseli area in west Wales, some 225 km away. On geochemical grounds, based on a range of major and trace elements determined by laboratory-based X-ray fluorescence spectrometry, they have been divided into three groups (Groups 1–3). Subsequently, rare earth element data obtained by solution nebulization ICP-MS showed Group 2 Stone 45 to have been sourced from Cerrigmarchogion with Group 2 Stone 62 showing similarities to the outcrops of Carn Ddafad-las and Garn Ddu Fach. In order to test this possible link, portable XRF (pXRF) analyses were obtained in situ from Stone 62 at Stonehenge and from key outcrops in the Preseli.
To obtain reliable results from heterogeneous coarse-grained igneous rocks using pXRF to enable comparisons between orthostats and possible sources, a robust analytical strategy was developed. For outcrops this involved a series of horizontal traverses through individual outcrops comprising 10 to 15 analyses a few centimetres apart, giving 60–175 independent analyses per outcrop. This gives a large, analysed surface area per outcrop providing representative data and also has potential to show any vertical variation in source outcrops. Analyses were taken from similarly weathered surfaces on orthostats and outcrops to minimise compositional changes from surface weathering, and a minimum of 20 analyses were taken from orthostats at various locations across the stone. This approach provides a set of well-determined elements which can reliably be used for provenance studies (including K, Fe, Mn, Zn, Rb, Sr, Zr, Nb, Ba). Nickel, Ti and V are affected slightly more by weathering but still prove useful in comparisons, but Cr, used in earlier studies as a compositional discriminant with Ni, here has poor accuracy by pXRF and is not used.
The pXRF analyses show that Stone 62 sits within the same ‘compositional space’ (for multiple element concentrations and ranges) as analyses from Carn Ddafad-las and Garn Ddu Fach, two outcrops of the same intrusion which differ from all other analysed outcrops. More specifically, analyses from Stone 62 and Garn Ddu Fach overlap, these forming a subset of the analyses from Carn Ddafad-las, which shows a more extensive range of those same elements. On this basis it is suggested that Garn Ddu Fach is the likely source of Stonehenge non-spotted dolerite Stone 62, a suggestion supported by indistinguishable petrographic characteristics between Stone 62 and dolerite sample PGDF24 from Garn Ddu Fach.
With social rituals usually involving sound, an archaeological understanding of a site requires the acoustics to be assessed. This paper demonstrates how this can be done with acoustic scale models. ...Scale modelling is an established method in architectural acoustics, but it has not previously been applied to prehistoric monuments. The Stonehenge model described here allows the acoustics in the Late Neolithic and early Bronze Age to be quantified and the effects on musical sounds and speech to be inferred. It was found that the stone reflections create an average mid-frequency reverberation time of (0.64 ± 0.03) seconds and an amplification of (4.3 ± 0.9) dB for speech. The model has a more accurate representation of the prehistoric geometry, giving a reverberation time that is significantly greater than that measured in the current ruin and a full-size concrete replica at Maryhill, USA. The amplification could have aided speech communication and the reverberation improved musical sounds. How Stonehenge was used is much debated, but these results show that sounds were improved within the circle compared to outside. Stonehenge had different configurations, especially in terms of the positions of the bluestones. However, this made inaudible changes to the acoustics, suggesting sound is unlikely to be the underlying motivation for the various arrangements.
•First application of acoustic scale modelling to prehistoric stone circles.•A 1:12 acoustic scale model of Stonehenge was constructed and measured.•Applying Architectural Acoustics methods and knowledge for prehistoric archaeology.•Offers novel insight into how speech and musical sounds were altered by the acoustics of Stonehenge.
•The Stonehenge Altar Stone is considered to belong to the bluestone megalith grouping.•Historically, it has been thought to come from Wales, along with the other bluestones.•More detailed analysis ...has failed to find a source in Wales or adjacent areas.•We question whether the Altar Stone should not be ‘lumped’ with the Welsh bluestones.•We intend to broaden our search for the Altar Stone source into northern Britain.
Stone 80, the recumbent Altar Stone, is the largest of the Stonehenge foreign “bluestones”, mainly igneous rocks forming the inner Stonehenge circle. The Altar Stone’s anomalous lithology, a sandstone of continental origin, led to the previous suggestion of a provenance from the Old Red Sandstone (ORS) of west Wales, close to where the majority of the bluestones have been sourced (viz. the Mynydd Preseli area in west Wales) some 225 km west of Stonehenge. Building upon earlier investigations we have examined new samples from the Old Red Sandstone (ORS) within the Anglo-Welsh Basin (covering south Wales, the Welsh Borderland, the West Midlands and Somerset) using traditional optical petrography but additionally portable XRF, automated SEM-EDS and Raman Spectroscopic techniques. One of the key characteristics of the Altar Stone is its unusually high Ba content (all except one of 106 analyses have Ba > 1025 ppm), reflecting high modal baryte. Of the 58 ORS samples analysed to date from the Anglo-Welsh Basin, only four show analyses where Ba exceeds 1000 ppm, similar to the lower range of the Altar Stone composition. However, because of their contrasting mineralogies, combined with data collected from new automated SEM-EDS and Raman Spectroscopic analyses these four samples must be discounted as being from the source of the Altar Stone. It now seems ever more likely that the Altar Stone was not derived from the ORS of the Anglo-Welsh Basin, and therefore it is time to broaden our horizons, both geographically and stratigraphically into northern Britain and also to consider continental sandstones of a younger age. There is no doubt that considering the Altar Stone as a ‘bluestone’ has influenced thinking regarding the long-held view to a source in Wales. We therefore propose that the Altar Stone should be ‘de-classified’ as a bluestone, breaking a link to the essentially Mynydd Preseli-derived bluestones.
Keeping time at Stonehenge Darvill, Timothy
Antiquity,
04/2022, Letnik:
96, Številka:
386
Journal Article
Recenzirano
Odprti dostop
Scholars have long seen in the monumental composition of Stonehenge evidence for prehistoric time-reckoning—a Neolithic calendar. Exactly how such a calendar functioned, however, remains unclear. ...Recent advances in understanding the phasing of Stonehenge highlight the unity of the sarsen settings. Here, the author argues that the numerology of these sarsen elements materialises a perpetual calendar based on a tropical solar year of 365.25 days. The indigenous development of such a calendar in north-western Europe is possible, but an Eastern Mediterranean origin is also considered. The adoption of a solar calendar was associated with the spread of solar cosmologies during the third millennium BC and was used to regularise festivals and ceremonies.
•Rare earth element geochemistry applied to provenancing the Stonehenge bluestones.•New data suggests Groups 1 and 3 spotted dolerites may be from a single source.•The source of one Stonehenge ...non-spotted dolerite is identified as Cerrigmarchogion.•The source of three other non-spotted dolerites remains uncertain.•The REE data are analysed using shape factors derived from polynomial curve fitting.
The doleritic bluestones of Stonehenge, sourced from the Mynydd Preseli in west Wales, have been previously classified into three geochemical groups on the basis of compatible element geochemistry (Bevins et al., 2014). The majority of Group 1 (spotted) dolerites were identified as coming from the outcrop of Carn Goedog, Group 3 (spotted) dolerites were linked to the outcrops Carn Breseb, Carn Gyfrwy, outcrops in the vicinity of Carn Alw and an un-named outcrop west of Carn Ddafad-las and Group 2 (non-spotted) dolerites were identified as coming from either Cerrigmarchogion or Craig Talfynydd. A sub-set of the samples used by Bevins et al. (2014) have been re-analysed by solution nebulisation ICP-MS, including analyses of the rare earth elements (REE).
Analysis of the REE data reveals that Groups 1 and 3 dolerites from both Stonehenge and the Preseli have very similar REE patterns which strongly suggests that they are derived from a single intrusive body. Group 2 non-spotted dolerites are now divided, on the basis of their REE contents, into four Preseli and two Stonehenge sub-groups, (Groups 2i-2iv and Groups 2v-2vi, respectively) while Stonehenge orthostat sample SH44 plots apart from all other Stonehenge and Preseli samples in all discriminant diagrams used. The new data show that Preseli Group 2i dolerites have very distinct concave down “humped” patterns and bear no resemblance to any analysed Stonehenge dolerites. The source of Stonehenge Group 2v dolerites remains equivocal; they plot close to Preseli Group 2ii dolerites from Carn Ddafad-las and Garn Ddu Fach and have in common the presence of notable positive Eu anomalies, but they show minor differences, especially in relation to their Gdn/Ybn ratios. However, Stonehenge orthostat sample SH45 shows a near identical REE composition to Preseli Group 2iii dolerites from Cerrigmarchogion.
In terms of the interpretation of REE contents and chondrite-normalized patterns we found no differences whether using the ‘standard’ techniques used by geochemists, based on chondrite-normalized elemental ratios and values, or the quantitative approach using shape factors derived from polynomial curve fitting.
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