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Dr George Nash of Bristol’s Department of Archaeology and Anthropology said the engraving, found by geologist Alan Bowring, could be more than 4,000 years old.
Mr Bowring came across the stone last year while he was examining the site, on land maintained by the National Trust, for clues to its geological history. Its precise location in the Brecon Beacons has not been revealed.
The stone, which measures around 1.45m by 0.5m, has 12 cup (hollow) marks of various shapes and sizes on its face. Now lying flat on the ground, it could once have stood upright and served as a way marker (standing stone) for farming communities. Such stones have been discovered in other parts of the UK but are rare in mid-Wales.
Based on the shape of the stone and its engravings, Dr Nash believes it probably dates from the Early to Middle Bronze Age period: 2,500 BC to 1,500 BC.
Dr Nash said: “There are a large number of prehistoric ritual sites in the Brecon Beacons but this is the first evidence of prehistoric rock art ever to be recorded in this part of Wales.
“We don’t know of any other later prehistoric standing stones in the Beacons that are cup marked. Such marks are the most common later prehistoric rock art form in Britain and Europe, but their occurrence in mid Wales is rare.”
As part of a much wider research project, Dr Nash will be undertaking, along with a team from the National Trust and the Brecon Beacons National Park Service, a thorough landscape survey of the immediate area. A fundamental part of the survey will be to trace and digitally record the cupmarked stone.
Header Image : Detail of the recumbent cupmarked stone – Dr G. H. Nash
Contributing Source : University of Bristol
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Dr George Nash from Bristol’s Department of Archaeology and Anthropology is involved in research which is taking a novel approach to solving the mystery.
The ‘Landscape and Perception Project’, led by Paul Devereux and Jon Wozencroft from the Royal College of Art, has been assessing the archaeoacoustic value of the bluestones, with Dr Nash and prehistorian Professor Timothy Darvill of Bournemouth University acting as advisors on the project.
The builders of Stonehenge transported thirty or more giant bluestones 260 km from the prehistoric stone quarry of Carn Menyn Ridge in Mynydd Preseli, South-west Wales to Salisbury Plain.
The Royal College of Art team tested over a thousand rocks at points all along the Carn Menyn Ridge and found that on average, between five and ten per cent of the rocks ‘ring’ when hit with a hammer-stone. In some localised areas, the figure rises significantly to between 15 and 20 per cent.
The researchers then assessed the bluestones that form one of the circles at Stonehenge. They found that, although many of the bluestones within the monument have been moved or set in concrete, at least three rang and had a similar resonance to those recorded at Carn Menyn Ridge.
In a BBC interview, Dr Nash said: “For many years archaeologists have been obsessed with Stonehenge being just merely a visible entity. Clearly, there are other factors afoot whereby the ringing stones would have created a unique soundscape.
“During its prehistoric past Stonehenge would have been a theatre of performance, where the sound as well as the lustre and colour of the bluestones would have formed an essential element in the ritual activity of this building.”
Contributing Source : University of Bristol
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Wood samples from the ships have been analysed by a group of scientists from the University of Gothenburg, Stockholm University and University of Calgary. The results are published in the latest issue of Scientific Reports.
Scientists from the same team have previously reported large amounts of sulphur and iron accumulation in the warship Vasa. In that study, the scientists found an outbreak of acidity and sulphate salts on the surface of the hull and other wooden objects.
‘This is the result of biological and chemical processes that occur naturally in low-oxygen waters and in sediments,’ says Yvonne Fors from the Department of Conservation at the University of Gothenburg and one of the scientists behind the article.
However, even if sulphur and iron accumulation is commonly occurring in old waterlogged wooden shipwrecks, it can cause problems for future preservation of the ships in a museum environment.Ships of high archaeological value
The Ghost wreck was found by coincidence in the Baltic Sea in 2003. The Dutch merchant vessel from the 1600s was discovered by a private diving company in connection with a search for the DC3 that vanished in the area in the 1950’s. The Ghost wreck has turned out to be of great archaeological importance, and there are far-reaching plans to recover, and conserve the ship. If the samples analysed thus far are representative of the entire hull, the ship may not have to face the same problems as the Vasa.
‘The iron amounts in the wood seem to be comparatively low, and the potentially most aggressive sulphur compounds don’t seem to occur in any significant levels. But we can’t be more certain until we’ve done some more analyses. The more we know about the chemical composition of the wood, the better the conservation efforts can be prepared,’ says Fors.More ships will probably be recovered
Also the royal warship Crown may eventually be recovered. ‘We have analysed samples from the Crown during a few years and have now also had the opportunity to analyse samples from the warship Sword, which was wrecked in the same battle in 1676,’ says Fors.
The Crown displays potentially more aggressive sulphur compounds and higher iron concentrations than the Ghost wreck. Of the three studied ships, the highest levels of both sulphur and iron were found in wood samples from the Sword.
Similar accumulation has previously been analysed in wood samples from the Vasa, Riksnyckeln, Götavraket, Stora Sofia, the British Mary Rose, the Australian Batavia and the Viking ships of Skuldelev.
Contributing Source : University of Gothenburg
New research led by the University of Exeter contests the long held belief that oxygenation of the atmosphere and oceans was a pre-requisite for the evolution of complex life forms.
The study, published today in the leading journal Nature Geoscience, builds on the recent work of scientists in Denmark who found that sponges – the first animals to evolve – require only small amounts of oxygen.
Professor Tim Lenton of the University of Exeter, who led the new study, said: “There had been enough oxygen in ocean surface waters for over 1.5 billion years before the first animals evolved, but the dark depths of the ocean remained devoid of oxygen. We argue that the evolution of the first animals could have played a key role in the widespread oxygenation of the deep oceans. This in turn may have facilitated the evolution of more complex, mobile animals.”
The researchers considered mechanisms by which the deep ocean could have been oxygenated during the Neoproterozoic Era (from 1,000 to 542 million years ago) without requiring an increase in atmospheric oxygen.
Crucial to determining oxygen levels in the deep ocean is the balance of oxygen supply and demand. Demand for oxygen is created by the sinking of dead organic material into the deep ocean. The new study argues that the first animals reduced this supply of organic matter – both directly and indirectly.
Sponges feed by pumping water through their bodies, filtering out tiny particles of organic matter from the water, and thus helping oxygenate the shelf seas that they live in. This naturally selects for larger phytoplankton – the tiny plants of the ocean – which sink faster, also reducing oxygen demand in the water.
By oxygenating more of the bottom waters of shelf seas, the first filter-feeding animals inadvertently increased the removal of the essential nutrient phosphorus in the ocean. This in turn reduced the productivity of the whole ocean ecosystem, suppressing oxygen demand and thus oxygenating the deep ocean.
A more oxygen-rich ocean created ideal conditions for more mobile animals to evolve, because they have a higher requirement for oxygen. These included the first predatory animals with guts that started to eat one another, marking the beginning of a modern marine biosphere, with the type of food webs we are familiar with today.
Professor Lenton added: “The effects we predict suggest that the first animals, far from being a passive response to rising atmospheric oxygen, were the active agents that oxygenated the ocean around 600 million years ago. They created a world in which more complex animals could evolve, including our very distant ancestors.”
Professor Simon Poulton of the University of Leeds, who is a co-author of the study, added: ″This study provides a plausible mechanism for ocean oxygenation without the requirement for a rise in atmospheric oxygen. It therefore questions whether the long-standing belief that there was a major rise in atmospheric oxygen at this time is correct. We simply don’t know the answer to this at present, which is ultimately key to understanding how our planet evolved to its current habitable state. Geochemists need to come up with new ways to decipher oxygen levels on the early Earth.″
Header Image : Aplysina_archeri : WikiPedia
Contributing Source : University of Exeter
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Scientists studied seafloor sediments to determine how the temperature of the North Atlantic and its localised atmospheric circulation had altered. Warm surface waters flowing across the North Atlantic, an extension of the Gulf Stream, and warm westerly winds are responsible for the relatively mild climate of Europe, especially in winter. Slight changes in the transport of heat associated with these systems can led to regional climate variability, and the study findings matched historic accounts of climate change, including the notoriously severe winters of the 16th and 18th centuries which pre-date global industrialisation.
The study found that changes in the Sun’s activity can have a considerable impact on the ocean-atmospheric dynamics in the North Atlantic, with potential effects on regional climate.
Predictions suggest a prolonged period of low sun activity over the next few decades, but any associated natural temperature changes will be much smaller than those created by human carbon dioxide emissions, say researchers.
The study, led by Cardiff University scientists, in collaboration with colleagues at the University of Bern, is published today in the journal Nature Geoscience.
Dr Paola Moffa-Sanchez, lead author from Cardiff University School of Earth and Ocean Sciences, explained: “We used seafloor sediments taken from south of Iceland to study changes in the warm surface ocean current. This was done by analysing the chemical composition of fossilised microorganisms that had once lived in the surface of the ocean. These measurements were then used to reconstruct the seawater temperature and the salinity of this key ocean current over the past 1000 years.”
The results of these analyses revealed large and abrupt temperature and salinity changes in the north-flowing warm current on time-scales of several decades to centuries. Cold ocean conditions were found to match periods of low solar energy output, corresponding to intervals of low sunspot activity observed on the surface of the sun. Using a physics-based climate model, the authors were able to test the response of the ocean to changes in the solar output and found similar results to the data.
“By using the climate model it was also possible to explore how the changes in solar output affected the surface circulation of the Atlantic Ocean,” said Prof Ian Hall, a co-author of the study. “The circulation of the surface of the Atlantic Ocean is typically tightly linked to changes in the wind patterns. Analysis of the atmosphere component in the climate model revealed that during periods of solar minima there was a high-pressure system located west of the British Isles. This feature is often referred to as atmospheric blocking, and it is called this because it blocks the warm westerly winds diverting them and allowing cold Arctic air to flow south bringing harsh winters to Europe, such as those recently experienced in 2010 and 2013.”
Meteorological studies have previously found similar effects of solar variability on the strength and duration of atmospheric winter blockings over the last 50 years, and although the exact nature of this relationship is not yet clear, it is thought to be due to complex processes happening in the upper layers of the atmosphere known as the stratosphere.
Dr Paola Moffa-Sanchez added: “In this study we show that this relationship is also at play on longer time-scales and the large ocean changes, recorded in the microfossils, may have helped sustain this atmospheric pattern. Indeed we propose that this combined ocean-atmospheric response to solar output minima may help explain the notoriously severe winters experienced across Europe between the 16th and 18th centuries, so vividly depicted in many paintings, including those of the famous London Frost Fairs on the River Thames, but also leading to extensive crop failures and famine as corroborated in the record of wheat prices during these periods.”
The study concludes that although the temperature changes expected from future solar activity are much smaller than the warming from human carbon dioxide emissions, regional climate variability associated with the effects of solar output on the ocean and atmosphere should be taken into account when making future climate projections.
Contributing Source : Cardiff University
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