This economic, social and cultural analysis of the nature and variety of production and consumption activities in households in Kent and Cornwall yields important new insights on the transition to ...capitalism in England.
Later prehistoric settlement in Cornwall and the Isles of Scillyreports on the excavation between 1996 and 2014 of five later prehistoric and Roman period settlements. All the sites were ...multi-phased, revealing similar and contrasting occupational patterns stretching from the Bronze Age into the Iron Age and beyond.
This article is centred around a detailed review of D.H. Frost’s new (2023) critical edition and translation of the Cornish and Latin text Sacrament an Alter, in both its theological/historical and ...its philological/linguistic aspects. First, Dr Frost’s exposition of his text’s remarkable background is placed against the constantly changing character of official Tudor ideology, and the ecclesiological lens through which he views his material discussed. Points from his linguistic analysis (including revivalist reconstructions) are then examined and, prompted by Frost’s portrayal of the state of Cornish-language literacy in the last quarter of the sixteenth century, similarities are adduced with the known situation of near-contemporary Manx Gaelic. Traditional Cornish went into ultimately terminal decline, but Manx went on to receive both the Prayer Book and the Bible in translation; Cornwall’s disadvantage in not constituting a diocese in its own right is suggested as a significant factor in the contrasting fates of the two small Celtic languages in question. Finally, attention is drawn to the potentially striking efficacy of small networks of dedicated scholars, whatever their time and place.
During November and December 2014, Cornwall Archaeological Unit undertook a programme of archaeological excavation in advance of construction of a road corridor to the south of Newquay. Evidence for ...Middle Bronze Age occupation took the form of a hollow-set roundhouse; however, the majority of the excavated features have been dated to the Iron Age and Roman periods. The area was enclosed as fields associated with extensive settlement activity throughout the last centuries cal BC into the third century AD.
The excavations revealed the character of settlement-related activity during the later prehistoric and Roman periods. The evidence strongly suggests growing intensification of agriculture, with ditched fields and enclosures appearing in the landscape from the later Iron Age and into the Roman period.
The results shed light on later prehistoric and Roman practices involving the division of the landscape with ditched fields and enclosed buildings. Many of the structures and pits were found to be set within their own ring-ditched enclosures or hollows, and the field system ditches were in some instances marked by 'special' deposits. As has previously been demonstrated for Middle Bronze Age roundhouses, structures could be subject to formal abandonment processes. Gullies and hollows were deliberately infilled, so that they were no longer visible at surface. However, unlike the abandoned Bronze Age roundhouses, the later structures appear to have been flattened and not monumentalized. In other words, buildings could be both etched into and subsequently erased from the landscape and thereby forgotten.
This volume takes the opportunity presented by investigations on the Newquay Strategic Road to discuss the complexity of the archaeology, review the evidence for 'special' deposits and explore evidence for the deliberate closure of buildings especially in later prehistoric and Roman period Cornwall. Finally, the possible motives which underlie these practices are considered.
Includes contributions by Ryan S Smith, Dana Challinor, Julie Jones, Graeme Kirkham, Anna Lawson-Jones, Henrietta Quinnell and Roger Taylor.
Microplastics (plastic particles, 0.1 μm–5 mm in size) are widespread marine pollutants, accumulating in benthic sediments and shorelines the world over. To gain a clearer understanding of ...microplastic availability to marine life, and the risks they pose to the health of benthic communities, ecological processes and food security, it is important to obtain accurate measures of microplastic abundance in marine sediments. To date, methods for extracting microplastics from marine sediments have been disadvantaged by complexity, expense, low extraction efficiencies and incompatibility with very fine sediments.
Here we present a new, portable method to separate microplastics from sediments of differing types, using the principle of density floatation. The Sediment-Microplastic Isolation (SMI) unit is a custom-built apparatus which consistently extracted microplastics from sediments in a single step, with a mean efficiency of 95.8% (±SE 1.6%; min 70%, max 100%). Zinc chloride, at a density of 1.5 g cm−3, was deemed an effective and relatively inexpensive floatation media, allowing fine sediment to settle whilst simultaneously enabling floatation of dense polymers. The method was validated by artificially spiking sediment with low and high density microplastics, and its environmental relevance was further tested by extracting plastics present in natural sediment samples from sites ranging in sediment type; fine silt/clay (mean size 10.25 ± SD 3.02 μm) to coarse sand (mean size 149.3 ± SD 49.9 μm). The method presented here is cheap, reproducible and is easily portable, lending itself for use in the laboratory and in the field, eg. on board research vessels. By employing this method, accurate estimates of microplastic type, distribution and abundance in natural sediments can be achieved, with the potential to further our understanding of the availability of microplastics to benthic organisms.
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•Cheap, effective method for microplastic extraction from sediments.•High, reproducible recovery rates - 95.8%.•Comparison of three commonly used floatation media.•Zinc chloride (1.5 g cm−3) deemed an effective floatation medium.•Method applied to environmental samples across a range of sediment types.
We present a simple, portable method to extract microplastics from natural sediments of different grain size using zinc chloride density floatation, yielding accurate and reproducible results.
About 85% of all historically mined tin of about 27 million tonnes Sn is from a few tin ore provinces within larger granite belts. These are, in decreasing importance, Southeast Asia (Indonesia, ...Malaysia, Thailand, Myanmar), South China, the Central Andes (Bolivia, southern Peru) and Cornwall, UK. Primary tin ore deposits are part of magmatic-hydrothermal systems invariably related to late granite phases (tin granites, pegmatites, tin porphyries), and may become dispersed by exogenic processes and then eventually form placer deposits within a few km from their primary source, due to the density of cassiterite, its hardness and chemical stability. Alluvial placer deposits were usually the starting point for tin mining, and have provided at least half of all tin mined. The small-volume and late granite phases in spatial, temporal and chemical relationship to tin ore deposits are highly fractionated. Systematic element distribution patterns in these granite phases and their associated much larger multiphase granite systems suggest fractional crystallization as the main petrogenetic process controlling magmatic evolution and magmatic tin enrichment. Oxidation state controls the bulk tin distribution coefficient, with low oxidation state favoring incompatible behavior of divalent tin. Low oxidation state is also mineralogically expressed by accessory ilmenite (FeO TiO2) as opposed to accessory magnetite (FeO Fe2O3) in more oxidized melt systems. This difference in the accessory mineralogy and hence metallogenic potential (tin-bearing ilmenite-series versus barren magnetite-series granites), can be easily detected in the field by a hand-held magnetic susceptibility meter. The hydrothermal system is a continuation of the magmatic evolution trend and necessary consequence of the crystallization of a hydrous melt. The exsolved highly saline aqueous fluid phase, enriched in boron and/or fluorine plus a wide metal spectrum, can be accomodated and stored by the intergranular space in crystallized melt portions, or accumulate in larger physical domains, accompanied by focused release of mechanical energy (brecciation, vein formation), dependent on emplacement depth (pressure). The hydrothermal mobility of tin is largely as Sn2+-chloride complexes; the precipitation of tin as cassiterite involves oxidation. Tin typically characterizes the inner high-temperature part of much larger km-sized zoned magmatic-hydrothermal systems with the chemical signature Sn-W-Cu-As-Bi in the inner part (greisen, vein/stockwork/breccia systems, skarn) and a broader halo with vein- or replacement-style Pb-Zn-Ag-Sb-Au-U mineralization of lower temperature. This zoning pattern may also occur telescoped on each other. Active continental margins are the favorable site for both copper (−gold) and tin (−tungsten) systems. However, the narrowly segmented metal endowment and the episodic nature of ore formation suggest additional controls. These are the build-up of a subduction-derived metal and fluid inventory in the lower continental crust by flat-slab subduction (very little magmatism) for copper‑gold in the main arc, followed by large-scale intracrustal melting during mantle upwelling in the back arc for tin (chemically reduced reservoir rocks) and/or tungsten mineralization (less sensitive to oxidation state).
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•Tin granites display advanced degree of fractionation•Tin granites are of ilmenite series (reduced), irrespective of S-, I-, or A-type affinity•Hydrothermal tin solubility is optimal under reducing and highly saline conditions•Hydrothermal tin ore formation requires oxidation, fluid mixing, cooling
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