1,720,971 research outputs found
Mobility and migration in late Iron Age and early Medieval Ireland
No full textStrontium and oxygen isotope analysis has been performed on a selection of human teeth dating from late Iron Age and early Medieval Ireland to test the hypothesis that the appearance of new burial rites was associated with phases of migration from, and contact with, the Roman and Late Antique world. In particular, the appearance of crouched inhumations from the beginning of the 1st century CE, and the appearance of extended supine inhumations alongside the reappearance of crouched burials after the c. 4th century CE are investigated. Isotopic data favours the presence of non-local individuals during both periods. As parallels for virtually all of these new burial practices can be found elsewhere, for example throughout Iron Age and Roman Britain, the data are seen to support previously proposed theories that such burial practices were intrusive and reflected new rites associated with migrant peoples. This adds to the increasing body of evidence demonstrating that rather than being isolated, Ireland was very much part of a connected Europe throughout the entire period of Roman administration in the western provinces, and in the centuries after its demise
A non-local source of Irish Chalcolithic and Early Bronze Age gold
No full textLead isotope analyses of 50 Irish Chalcolithic and Early Bronze Age gold artefacts favour a gold source in southern Ireland. However when combined with major element analysis, the artefacts are not consistent with any Irish gold deposit analysed to date. Understanding the lead isotope signatures of ore deposits within a study region allows informed inferences to be drawn regarding the likelihood that an unanalysed ore deposit was exploited in the past. If an Irish gold source is assumed, then the gold is most likely to have originated from deposits hosted by Old Red Sandstone in the Variscan ore field of south-west Ireland. However, based on our current understanding of mineralisation in the region, this scenario is considered unlikely. A non-Irish source for the gold is therefore preferred – a scenario that may favour cosmologically-driven acquisition, ie, the deliberate procurement of a material from distant or esoteric sources. Available geochemical data, combined with current archaeological evidence, favour the alluvial deposits of south-west Britain as the most likely source of the gol
New insights into the source of Irish Chalcolithic and Early Bronze Age gold through lead isotope analysis?
No full textBoreham Cave, Littondale, North Yorkshire, UK: some geomorphological observations
Full text linkObservations made by the original explorers of Boreham Cave, a partly-submerged cave system on the northeastern flank of Littondale in the Yorkshire Dales, UK, have been augmented by recent studies of aspects such as overall cave morphology, geological and topographical setting, scallop geometry, sediment lithology, form and provenance, and speleothem ages. Consideration of the expanded dataset has enabled development of an interim cave development model for Boreham Cave itself, and supports speculation regarding its relationship to documented events during the Quaternary and with other cave systems in the wider area
Imaging of boron in altered mantle rocks illuminates progressive serpentinisation episodes
No full textSerpentinised mantle rocks reflect the cumulative sum of multiple alteration events, but to date, identifying distinct serpentinisation episodes has remained challenging due to limited knowledge of the spatial distribution of tracers of fluid-rock exchange. Here we present novel high spatial resolution (∼10 μm) boron, nickel, calcium, and lithium concentration maps combined with in situ boron isotope analyses of strongly serpentinised mantle peridotites from the Troodos ophiolite, Cyprus. Our maps indicate strongly heterogenous boron concentrations with high boron concentrations in early formed serpentine replacing olivine but much lower boron contents in mesh-textured serpentine and bastitic pyroxene. Late stage crosscutting serpentine veins have very low boron concentrations. In contrast, boron isotope measurements, made at coarser scales, are remarkably uniform (mean value +11.9 ± 3.2 %, 1σ, n = 49). We interpret the high boron serpentine as reflecting the partial preservation of an early pervasive serpentinisation episode by fluids with high boron concentrations sourced from the dehydration of the subducting Cyprus slab. Subsequent serpentine phases with moderate to low boron reflect progressive recrystallisation and leaching by low boron concentration meteoric waters.</p
The genesis of gold mineralisation hosted by orogenic belts: A lead isotope investigation of Irish gold deposits
Full text linkLead isotope analyses have been performed on 109 gold and 23 sulphide samples from 34 Irish gold occurrences, including 27 placers, and used to shed light on the sources of mineralising fluids and metals associated with gold mineralisation hosted by orogenic belts. The Pb isotope ratios of lode and placer gold range from 206Pb/204Pb=17.287-18.679, 207Pb/204Pb=15.382-15.661, and 208Pb/204Pb=37.517-38.635, consistent with the Pb isotopic data on previously reported Irish sulphide mineralisation. There is no evidence that gold mineralisation is associated with distinctive source regions, and it appears to have been derived from similar sources to those responsible for the widespread sulphide mineralisation in Ireland. It is inferred that the principal controls on the Au mineralisation are structural and not related to the distribution of Au in their source rocks. The range of Pb isotope ratios favours the interaction of multiple source reservoirs predominantly during the Caledonian Orogeny (c. 475-380Ma). Underlying basement was the primary control on two key sources of Pb. Gold occurrences located to the south-east of the Iapetus Suture are characterised by Pb compositions that derive predominantly from the Late Proterozoic crustal basement or overlying Lower Palaeozoic sediments, whilst those located north-west of the Iapetus Suture are characterised by less radiogenic Pb signatures derived predominantly from Late Proterozoic or older crustal basement. A third source, relatively enriched in radiogenic Pb, also played a role in the formation of a number of Irish gold occurrences, and may have been associated with syn- to post-orogenic intrusives. Magmatic processes may therefore have played an important role in the formation of some orogenic gold occurrences
Reindeer prey mobility and seasonal hunting strategies in the late Gravettian mammoth steppe
No full textReindeer are part of the faunal suite that dominated central Europe during the last glacial cycle. Their importance to Late Gravettian hunters as prey and a source of raw materials (hide, bone, antler) is well attested, however the context of Late Gravettian reindeer predation is lesser understood. This paper presents an investigation of human and reindeer predator-prey interactions at the Late Gravettian kill-butchery site of Lubná VI, Czech Republic. We reconstruct seasonal mobility (87Sr/86Sr, δ18O), diet (δ13C, δ15N) and season of death (dental cementum) of up to nine reindeer prey, to inform on the strategic choices made by Late Gravettian hunters. Results indicate that most hunted reindeer lived year-round in the foothills of the Bohemian-Moravian highlands near where Lubná is located, at altitudes between ~ 200–450 m above present sea level, while a smaller number showed evidence of seasonal migration between this area and the open plains of the Elbe river corridor (Bohemian Cretaceous basin). No evidence for long distance migration of reindeer was detected, indicating that productive local environments were supporting reindeer herds within a single annual territory. Meanwhile, areas higher than ~ 450 m above present sea level were avoided entirely by all analysed individuals, consistent with these areas being topographic barriers to movement due to climate severity. We conclude that hunters visited Lubná as part of a logistically-organised subsistence strategy, deliberately targeting reindeer in late autumn when fat supplies, hides and antler are in prime condition knowing that they would reliably encounter their prey at this location.</p
Grotta delle Incisioni dell’Addaura (Palermo, Prov. di Palermo), Grotta del Genovese, Levanzo (Favignana, Prov. di Trapani)
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