News Article | November 7, 2016
In 1721, missionary Hans Egede sailed a ship called The Hope from Norway to Greenland, seeking Norse farmers whom Europeans hadn't heard from in 200 years in order to convert them to Protestantism. He explored iceberg-dotted fjords that gave way to gentle valleys, and silver lakes that shimmered below the massive ice cap. But when he asked the Inuit hunters he met about the Norse, they showed him crumbling stone church walls: the only remnants of 500 years of occupation. "What has been the fate of so many human beings, so long cut off from all intercourse with the more civilized world?" Egede wrote in an account of the journey. "Were they destroyed by an invasion of the natives … [or] perished by the inclemency of the climate, and the sterility of the soil?" Archaeologists still wonder today. No chapter of Arctic history is more mysterious than the disappearance of these Norse settlements sometime in the 15th century. Theories for the colony's failure have included everything from sinister Basque pirates to the Black Plague. But historians have usually pinned most responsibility on the Norse themselves, arguing that they failed to adapt to a changing climate. The Norse settled Greenland from Iceland during a warm period around 1000 C.E. But even as a chilly era called the Little Ice Age set in, the story goes, they clung to raising livestock and church-building while squandering natural resources like soil and timber. Meanwhile, the seal-hunting, whale-eating Inuit survived in the very same environment. Over the last decade, however, new excavations across the North Atlantic have forced archaeologists to revise some of these long-held views. An international research collective called the North Atlantic Biocultural Organisation (NABO) has accumulated precise new data on ancient settlement patterns, diet, and landscape. The findings suggest that the Greenland Norse focused less on livestock and more on trade, especially in walrus ivory, and that for food they relied more on the sea than on their pastures. There's no doubt that climate stressed the colony, but the emerging narrative is not of an agricultural society short on food, but a hunting society short on labor and susceptible to catastrophes at sea and social unrest. Historian Poul Holm of Trinity College in Dublin lauds the new picture, which reveals that the Greenland Norse were "not a civilization stuck in their ways." To NABO archaeologist George Hambrecht of the University of Maryland in College Park, "The new story is that they adapted but they failed anyway." Ironically, just as this new picture is emerging, climate change once again threatens Norse settlements—or what's left of them. Organic artifacts like clothing and animal bones, preserved for centuries in the deep freeze of the permafrost, are decaying rapidly as rising temperatures thaw the soil. "It's horrifying. Just at the time we can do something with all this data, it is disappearing under our feet," Holm says. In 1976, a bushy-bearded Thomas McGovern, then 26, arrived for the first time on the grassy shore of a fjord in southern Greenland, eager to begin work on his Ph.D. in archaeology. The basic Norse timeline had already been established. In the ninth century, the advances in seafaring technology that enabled Scandinavian Vikings to raid northern and central Europe also opened the way for the Norse, as they came to be known in their later, peaceful incarnations, to journey west to Iceland. If the unreliable Icelandic Sagas, written centuries later, are to be believed, an enterprising Icelander named Erik the Red led several ships to Greenland around 985 C.E. The Norse eventually established two settlements, with hundreds of farms and more than 3000 settlers at their peak. But by 1400, the settlement on the island's western coast had been abandoned, according to radiocarbon dates, and by 1450 the inhabitants in the Eastern Settlement on the island's southern tip were gone as well. Data gathered in the 1980s by McGovern and others suggested that the colonies were doomed by "fatal Norse conservatism in the face of fluctuating resources," as McGovern, now at Hunter College in New York City, wrote at the time. The Norse considered themselves farmers, he and others thought, tending hay fields despite the short growing season and bringing dairy cows and sheep from Iceland. A 13th century Norwegian royal treatise called The King's Mirror lauds Greenland's suitability for farming: The sun has "sufficient strength, where the ground is free from ice, to warm the soil so that the earth yields good and fragrant grass." Bone samples suggest that even small farms kept a cow or two, a sign of status back in Norway, and written records mention dairy products including cheese, milk, and a yogurt called skyr as essential parts of the diet. "There were no activities more central to Norse identity than farming," archaeologist William Fitzhugh of the Smithsonian Institution's National Museum of Natural History (NMNH) in Washington, D.C., wrote in 2000. Geographer Jared Diamond of the University of California, Los Angeles, popularized this view in his 2005 bestseller, Collapse. The Norse "damaged their environment" as they had done in Iceland, Diamond asserted, based on analyses of dust that suggested erosion caused by felling trees, agriculture, and turf cutting. While foolishly building churches with costly bronze bells, Diamond said, Greenland's Norse "refused to learn" Arctic hunting techniques from the Inuit, who hunted seals and fish year-round. He noted grisly evidence of calamity at a few sites in the Western Settlement: bones of pet dogs with cut marks on them, suggesting hunger; and the remains of insects that feast on corpses, suggesting too few survivors to bury their loved ones. "Every one of [the Norse] ended up dead," Diamond said in 2008. This narrative held sway for years. Yet McGovern and others had found hints back in the 1980s that the Norse didn't entirely ignore Greenland's unique ecology. Even Diamond had noted that bones of seals comprised 60% to 80% of the bones from trash heaps, called middens, found at small Norse farms. (He believed, though, that only the poorer settlers ate seal meat.) Written sources reported that the Norse routinely rowed up to 1500 kilometers to walrus migratory grounds near Disko Bay in western Greenland. They returned with countless walrus snouts, whose ivory tusks they removed and prepared for trade with Europe. The Norse paid tithe to the Norwegian king and to the Catholic Church in ivory, and traded it with European merchants for supplies like iron, boat parts, and wood. But McGovern dismissed the walrus hunt as "a curious adjunct," he recalls, echoing the scholarly consensus that farming was central. Three decades later here at Tasilikulooq (TA-SEE-LEAK-U-LOCK), a modern Inuit farm of green pastures flanked by lakes, a couple of McGovern's students and others are busy exploring the remains of a medium-sized farm that once housed sheep, goats, horses, and a few cows. Two graduate students in rubber overalls hose 700-yearold soil off unidentified excavated objects near a midden downhill from a collapsed house. A brown button the size of a nickel emerges on the metal sieve. "They found one more of those buttons," says archaeologist Brita Hope of the University Museum of Bergen in Norway, smiling, when word makes it back to the farmhouse the nine-member team uses as a headquarters for the month-long dig. "We could make a coat," a student jokes. But the function of the button matters a lot less than what it's made of: walrus tooth. Several walrus face bones have also turned up at the farm, suggesting that the inhabitants hunted in the communal Disko Bay expedition, says excavation leader Konrad Smiarowski of the City University of New York in New York City. These finds and others point to ivory—a product of Greenland's environment—as a linchpin of the Norse economy. One NABO dig in Reykjavik, for example, yielded a tusk, radiocarbon dated to about 900 C.E., which had been expertly removed from its skull, presumably with a metal tool. The find suggests that the early Icelandic Norse were "experienced in handling walrus ivory," NABO members wrote in a 2015 paper; it follows that the Greenlanders were, too. Although historians long assumed that the Norse settled Iceland and Greenland in search of new farmland, some researchers have recently suggested that the hunt for ivory instead drove the settlement of both islands. Walrus in Iceland were steadily extirpated after the Norse arrived there, likely hunted out by the settlers. The high value that medieval Europe placed on walrus ivory would have provided plenty of incentive to pursue it in Greenland. Craftsmen used ivory in luxury ornaments and apparel, and in objects like the famous Lewis chess set, discovered in Scotland in 1831. In 1327, an 802-kilogram parcel of Greenland tusks was worth a small fortune—the equivalent of roughly 780 cows or 60 tons of dried fish, according to tithing records analyzed in 2010 by University of Oslo archaeologist Christian Keller. "The Norse had found a cornucopia in the North Atlantic, a marine ecosystem just teeming with walruses and other animals," says historian Holm. They exploited it not just for ivory, but also for food, Smiarowski says as he huddles in a dimly lit side room here to review recent finds. One bag contains bones collected from a layer dating to the 1350s. A long, thin, cow bone had been split open, probably to eat the marrow. But most of the bones are marine: scraps of whale bone, jaw and skull fragments of harp seals, a bit of inner ear of a hooded seal. These two species of seal migrate north along Greenland shores in the spring, and Smiarowski thinks the Norse likely caught them with boats and nets or clubs. In 2012, NABO researchers clinched the case that the Greenlanders ate a marine diet by analyzing human bones in Norse graveyards. Animals that live in the sea have ratios of carbon and nitrogen isotopes that differ from those found in terrestrial animals, and this isotopic signature is passed on to the people who eat them. The Norse bones show that as the settlement developed from the 11th to the 15th century, their diet contained ever more marine protein. Far from clinging to livestock as temperatures fell, the Norse instead managed a successful subsistence system with "flexibility and capacity to adapt," wrote the author of the 2012 paper, Jette Arneborg from the National Museum of Denmark in Copenhagen. Nor were the Norse incompetent farmers, as Diamond and others have suggested. Soil geographer Ian Simpson of the University of Stirling in the United Kingdom says previous studies overestimated the Norse contribution to erosion in Greenland. New pollen and soil data show that the Norse allowed fields and what little forest existed to recover after tilling and turf cutting. And in analyses of soil and lake sediment cores, researchers have found chemical and paleoecological clues indicating that Norse farmers skillfully maintained pastures with manure fertilizer and irrigation ditches. Such findings, along with the ivory evidence, have transformed ideas about Norse society, says McGovern, whose beard is now white. "You start to see old data, like the seal bones in the middens, in a new light. It's exciting to get a chance to revise your old thinking before a younger colleague can," he says. "We used to think of Norse as farmers who hunted. Now, we consider them hunters who farmed." It was a sustainable lifestyle for hundreds of years. But in the 13th century, economics and climate began to conspire against the Norse. After 1250, a cooling climate posed multiple threats to a marine-oriented society reliant on seal and walrus. (Global average temperature fell by about a degree during the Little Ice Age, although scientists have struggled to quantify local cooling.) Even before the big chill set in, The King's Mirror describes ships lost and men who perished in ice. Historians and climatologists agree that as the cold spell continued, ice would have clogged the seas farther south and for longer each year, disrupting voyages. And concentrations of salt particles in glacier cores indicate that seas became stormier in the 15th century. Norsemen hunting migratory seals or walrus on the high seas would have been at increasing risk. The nomadic Inuit, by contrast, hunted seal native to the fjords, and rarely embarked on open-ocean hunts or journeys. Not only did the climate disrupt trade, but the market did, too. Around 1400, the value of ivory in Europe fell as tusks from Russian walrus and African elephants flowed into the continent. Even as surviving from marine resources became more difficult, the growing season on land shortened, and the meager pastures yielded even less. But soil and sediment analyses show that the farmers, too, tried to adapt, Simpson said, often fertilizing and watering their pastures more intensively as temperatures dropped. "We went in with the view that they were helpless in the face of climate change and they wrecked the landscape," Simpson says. Instead, he says, these "pretty good managers" actively adapted to the cooling climate. In the end, however, their best efforts fell short. At the grand bishop's seat of Gardar, 35 kilometers away by boat from the modest farm at Tasilikulooq, grass grows around the ruins of a cathedral, the bishop's residence, and myriad other buildings probably built by stonemasons shipped in from Norway. Stone shelters here once housed more than 100 cows—a sign of power in medieval Scandinavia. If the Greenland settlement was originally an effort to find and exploit the prized natural resource of ivory, rather than a collection of independent farmers, the society would have needed more top-down planning than archaeologists had thought, says Christian Koch Madsen of the Danish and Greenlandic National Museums in Copenhagen. His work and other research support that notion by revealing orchestrated changes in the settlement pattern as the climate worsened. Madsen carefully radiocarbon dated organic remains like wood from the ruins of 1308 Norse farms. The dates show that Gardar, like other rich farms, was established early. But they also suggest that when the first hints of the Little Ice Age appeared around 1250, dozens of outlying farms were abandoned, and sometimes reestablished closer to the central manors. The bones in middens help explain why: As temperatures fell, people in the large farms continued to eat beef and other livestock whereas those in smaller farms turned to seal and caribou, as Diamond had suggested. To maintain their diet, Greenland's powerful had to expand labor-intensive practices like storing winter fodder and sheltering cows. He thinks that larger farms got the additional labor by establishing tenant farms. The stresses mounted as the weather worsened, Madsen suspects. He notes that the average Norse farmer had to balance the spring- and summertime demands of his own farm with annual communal walrus and migratory seal hunts. "It was all happening at once, every year," Madsen says. Deprivation in lower societal strata "could eventually have cascaded up through the system," destabilizing large farms dependent on tithes and labor from small ones. The disrupted ivory trade, and perhaps losses at sea, couldn't have helped. The Greenland Norse simply could not hold on. It adds up to a detailed picture that most archaeologists studying the Norse have embraced. But not everyone agrees with the entire vision. Fitzhugh of NMNH, for one, questions the reconception of the colony as an ivory-focused trading post and still thinks farming was more important. "They couldn't get enough ivory to maintain 5000 people in the Arctic," he says. Fitzhugh does agree with Madsen and others on how the final chapter of the Greenland saga may have played out. Despite the signs of crisis at a few Western Settlement sites, those in the Eastern Settlement show no sign of a violent end. Instead, after farmhouses collapsed, remaining settlers scavenged the wood from them, suggesting a slow dwindling of population. The challenge for the average Greenlander to survive drove "a constant emigration" back to Iceland and Europe, Fitzhugh hypothesizes, "which could bring the Eastern [Settlement] to a close peacefully, without starvation or death by Inuit." The NABO team hopes future grants will allow them to fill out that picture. They're eager to start new excavations in the Western Settlement, where artifacts could shed light on any contact between the Norse and Inuit, a historical possibility about which there are little hard data. Time is running out. The Tasilikulooq excavation yielded well-preserved artifacts including wooden spoons, bowls, and a small wooden horse. But McGovern fears that its success may not be repeated. Thirty years ago most sites in the Eastern Settlement contained preserved bone, hair, feathers, and cloth. A NABO survey of 90 sites has found, however, that most organic samples "had pretty much turned to mush" as the permafrost thawed, Smiarowski says. Tasilikulooq was one of only three sites spared. Hans Egede, the missionary, wrote that he went to Greenland 500 years ago to save its people from "eternal oblivion." Today's archaeologists fear a different oblivion—that Greenland's prehistory will be lost unless it is quickly unearthed. As pioneers who weathered climate change, the Greenland Norse may hold lessons for society today. But the very changes that make those lessons urgent could keep them from ever being fully deciphered. Reporting for this story was supported by the Pulitzer Center on Crisis Reporting.
Khan F.R.,Roskilde University |
Syberg K.,Roskilde University |
Shashoua Y.,National Museum of Denmark |
Bury N.R.,King's College London
Environmental Pollution | Year: 2015
This study aimed to determine whether the uptake and localization of Ag in zebrafish was affected by the presence of polyethylene microplastic beads (PE MPBs). Zebrafish were exposed to 1 μg Ag L-1 (radiolabelled with 110mAg) for 4 and 24 h in the presence or absence of PE MPBs (10, 100 or 1000 MPBs mL-1), and one treatment in which MPBs (1000 MPBs mL-1) were incubated with Ag to promote adsorption. The presence of MPBs, at any of the tested doses, had no effect on the uptake or localization of Ag. However, exposure to the Ag-incubated MPBs (∼75% of the Ag bound to MPBs) significantly reduced Ag uptake at both time points and also significantly increased the proportion of intestinal Ag. This study demonstrates that microplastics can alter the bioavailability and uptake route of a metal contaminant in a model fish species. © 2015 Elsevier Ltd. All rights reserved.
News Article | June 18, 2016
Who knew you could strike gold "at the end of the rainbow"? Three amateur archaeologists have unearthed what could be considered the largest trove of Viking gold ever discovered in Denmark. Calling themselves as "Team Rainbow Power," the group of archaeologists uncovered seven bracelets from the Viking Age in a field in Jutland's Vejen Municipality. The ancient bracelets — one silver and six gold — are estimated to date around the year 900, according to the National Museum of Denmark. With a total weight of approximately 900 grams (1.98 pounds), the trove of seven bracelets is the biggest Viking gold discovery in the country. Marie Aagaard Larsen, one of the archaeologists, says she was only in the field for 10 minutes when they found the first bangle. She and her husband Christian Nedergaard Dreioee, together with their friend Poul Noergaard Pedersen, felt like it was almost unreal when they found more. After discovering the first three bangles, the trio of amateur archaeologists asked help from a professional — Lars Grundvad from Sønderskov Museum. At the museum, Grundvad and his colleagues had once talked about how interesting it could be to check out the field in Vejen Municipality with metal detectors because in 1911, there had been a 67-gram gold chain unearthed there. He says the gold chain was probably part of the same trove, and that two of the seven bracelets were likely made in the "Jelling style," a design that is associated with the elite members of Viking society. What Were The Bangles For? Viking Age expert Peter Pentz of the National Museum says the seven bangles could have been used by a Viking leader to reward his loyal followers or form alliances. He says the discovery is quite unique, given that even finding one of the bangles is a major achievement. "It is very special to find seven," says Pentz. The majority of treasure discovered from the Viking Age is silver, says Pentz. Even if there was gold, Pentz says it was only always a small part, unlike the recent find. He says the bangles could have been buried through some form of ritual at some point in the year 900, or it was buried because someone wanted to keep it but was never able to retrieve it again. The National Museum in Copenhagen will further investigate the bracelets to try to uncover why the valuables ended up where they were found. In the meantime, Sønderskov Museum will put the treasure on display before it is sent to Copenhagen. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | November 3, 2016
A set of broken stones covered with etchings of lines and squares, discovered at a 5,000-year-old sacred site in Denmark, may be some of humankind’s earliest maps, according to archaeologists. The researchers think the inscribed stones are symbolic maps of local landscapes, and were perhaps used in rituals by Stone Age farmers who hoped to magically influence the sun and the fertility of their farmlands. Fragments of 10 of the "map stones" or "landscape stones" were found in June, during excavations of a round, earth-walled enclosure at the Vasagard archaeological site on Bornholm, a Danish island in the Baltic Sea. [See Photos of the Scratched "Map Stones" Found in Denmark] Excavations of the enclosure since the 1990s have found hundreds of broken flat stones inscribed with patterns of radiating straight lines, called "sun stones" or "solar stones" ("solsten"in Danish). Archaeologists have said these artifacts are likely from the rituals of a Neolithic sun-worshipping religion that existed about 5,000 years ago. But the map stones are inscribed with squares and lines that look like fields, fences and plants, said archaeologist Flemming Kaul, the curator and senior researcher in prehistory at the National Museum of Denmark. "There was one particular stone that seems to be rather complicated, and we all agree that it looks like some sort of a map — not a map in our modern sense, but a stylized map," Kaul told Live Science. "And I could see some similarities with rock carvings from the Alps in northern Italy, dated to the same period of time, which are interpreted as symbolic landscapes — and that is what I believe we have found now." The most detailed of the newly discovered map stones went on display in October at the Moesgaard Museum in Aarhus, Denmark. It measures about 2 inches (5 centimeters) across, and has been broken into three pieces. One triangular piece has not yet been found, the researchers said. "That is one that seems to be very complex, with different sorts of fields, and something which looks like plants, which could be a symbol for a crop like barley, and other details that look like fences," Kaul said. "And it's fascinating that even though it's so small, you can certainly see that these patterns have been very deliberately made." Kaul said the stone was probably crushed during an ancient ritual, like what the researchers saw with many sun stones also found at the site. The pieces were then deposited in the rings of ditches that surround the sacred enclosure sometime between 2900 B.C. and 2700 B.C., according to the archaeologists. "Often when ritual objects have had a certain life cycle, then they are deposited at a sacred place, perhaps also to enhance the magic of the ritual which has just been performed with them," Kaul said. "And of course, when they are broken, then they are not working more in the human world — but they are still working in another [spirit] world, by being placed in the ditches of these sacred sites." Kaul thinks the map stones and sun stones from Bornholm were used together in ceremonies to influence the effects of the sun on the fertility of a particular piece of land. "[T]hey could have passed the sun images over the small field images in order to enhance some magic, which could give the sun more light, for example, such as in the spring, when the sun should give more light so that crops can grow," he added. Here comes the sun Kaul sees a link between the evidence for solar rituals at Bornholm and evidence of similar beliefs elsewhere in Neolithic Europe, a time of transition from nomadic hunter-gatherer groups to settled farming communities. "Sun images must have something to do with a solar cult — and we have many other European indications of that, such as Stonehenge in England from about the same time, and passage graves in Ireland that are oriented towards the midwinter sunrise. And now we have these early pictures of the sun in Denmark," he said. He also noted the similarities between the map stones from Denmark and rock carvings in the Val Camonica and other Alpine regions of northern Italy and France, which have been interpreted by archaeologists as symbolic farm landscapes used in Neolithic rituals. "The Italian archaeologists give these square features that they interpret as fields the name of 'topographical elements' — so it is not a map in our modern sense, but it is somehow a rendering of fields and field systems," Kaul said. "And so it is very interesting to find these topographical elements here in Scandinavia, and in this minute form." The similarities are not evidence of direct contact throughout Europe 5,000 years ago, but they could reflect common ideas among Neolithic farming peoples about the sun and the fertility of their lands, he said. "When you also look at the Italian material, then it gives you a feeling that these map stones are not just isolated phenomenon — but that we are looking at a trend of a general European development here, and also in a religious or spiritual sense," Kaul added. An article about the map stones from the Vasagaard enclosure on Bornholm, written by archaeologists Jens Andresen of Aarhus University and Michael Thorsen of the Bornholm Museum, was published in October in the Danish archaeological magazine Skalk. Kaul accepts that the interpretation of the map stones could be controversial: "About 20 years ago, after the first solar stones were found, I wrote about it for Skalk – and even the editor of the magazine didn't believe it," he said. "And now, after 20 years, we have found more than 200 solar stones, and they are one the most important things from Bornholm … so let's wait a couple of years to see if there are more map stones to come."
Frei R.,Copenhagen University |
Poire D.,National University of La Plata |
Frei K.M.,National Museum of Denmark |
Frei K.M.,Copenhagen University
Chemical Geology | Year: 2014
We have investigated the pathway of chromium from its mobilization on land and along its riverine transport in a subtropical region of South America (Misiones Province, Argentina), in an attempt to link Cr stable isotope compositions recently measured in seawater with signals prevailing in rivers and, ultimately, with Cr isotope effects observed during oxidative surface weathering in subtropical red soils. Cr concentrations and stable Cr isotopic compositions (expressed as δ53Cr ‰ values) in two typical and representative surface profiles of weathered basalt show significant depletion of Cr in the soils of up to 50%, together with pronounced negatively fractionated δ53Cr values which are indicative of oxidative mobilization of heavy Cr(VI) into the run-off. The behavior of Cr in the studied weathering profiles is not correlated with that of other redox sensitive elements, such as Ce and U; this is essentially due to the affinity of REE and U, but not Cr with secondary phosphates which form during weathering processes.Smaller tributaries in NW Argentina to the Paraná River (second largest river in South America) carry dissolved Cr in the order of 0.7-1.4ppb (13-27nM) with δ53Cr values of +0.2 to +0.4‰, balancing the negatively fractionated weathering products. The isotope composition and concentration of dissolved Cr in the ca. 1200km long Paraná River from Misiones to its estuary and discharge area into the South Atlantic Ocean remains relatively constant with an average Cr concentration around 2.4ppb (46nM) and an average δ53Cr value of +0.32‰. The Cr concentration in the estuary itself drops by ca. 50% but with only minor change in its Cr isotope composition. Results from the Paraná estuary are identical with recently analyzed surface seawater from the Argentine Basin with Cr contents of ~0.3ppb (~6nM) and δ53Cr values ~+0.4‰ (Bonnand et al., 2013), and indicate that there is only a minimal Cr isotopic variability during riverine transport, even during long transport distances as shown in our example of the Paraná River. Simple Cr input flux calculations reveal that the Paraná River accounts for ~5% of the total yearly Cr flux to the world's oceans today and that its isotopic signature seems to be, at least locally, imparted to the surface seawater of the Argentine Basin. Whether or not this Cr isotope signature is generally exhibited by the world's oceans needs further investigations, particularly the characterization of seawater around the globe. © 2014 Elsevier B.V.
Andresen S.T.,Museet for Varde By og Omegn |
Karg S.,National Museum of Denmark
Vegetation History and Archaeobotany | Year: 2011
During the last decade, a new type of structure has been found at several archaeological sites in Denmark. These structures can be interpreted as having been used for retting the stems of textile plants such as Linum usitatissimum L. (flax), Cannabis sativa L. (hemp) and Urticadioica L. (nettle). In order to obtain fine threads for textile production, these plants need to pass through several biological and technical processes. The first process is the retting of the plant stems to dissolve the pectin which fixes the fibres to the stalk. This can either be done by water retting, where the plant stems are soaked in lakes, rivers or waterlogged pits, or by field retting, where the stems are laid out in a field in order to absorb dew. The first method is shorter in time and the process is easier to control. In this article, details of archaeological structures are presented from eight sites in southern Scandinavia that can be interpreted as textile plant retting pits. The constructions of the pits are described, as well as the archaeological contexts and the relevant associated archaeobotanical records. Some of the presented sites, of which the oldest are dated to the late Bronze Age and early pre-Roman Iron Age (800-250 b. c.) and the youngest to the Viking Age (a. d. 750-1050), indicate a large-scale production of flax that had been underestimated up to now. © 2011 Springer-Verlag.
Mortensen M.N.,National Museum of Denmark |
Matthiesen H.,National Museum of Denmark
Analytical and Bioanalytical Chemistry | Year: 2013
Rates of oxygen consumption have been measured over extended time periods for 29 whole samples of conserved, archaeological wood and four samples of fresh, unconserved wood, at 50 % relative humidity and room temperature. Samples from the Swedish Warship Vasa and the Danish Skuldelev Viking ships are included. Most rates were close to 1 μg O2 (g wood)-1 day-1 and the process persisted for several years at least. Consumption of oxygen is related to change in chemical composition, which is, in turn, related to degradation. It is thus demonstrated that despite conservation, waterlogged archaeological wood continues to degrade in a museum climate. [Figure not available: see fulltext.] © 2013 Springer-Verlag Berlin Heidelberg.
Gregory D.J.,National Museum of Denmark
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2015
SASMAP's purpose is to develop new technologies and best practices in order to locate, assess and manage Europe's underwater cultural heritage in a more effective way than is possible today. SASMAP has taken an holistic-and process-based approach to investigating underwater environments and the archaeological sites contained therein. End user of the results of SASMAP are severalfold; i) to benefiet the SMEs involved in the project and development of their products for the offshore industry (not just for archaeological purposes) ii) a better understanding of the marine environment and its effect on archaeological materials iii) the collation of the results from the project into guidelines that can be used by cultural resource managers to better administer and optimise developer lead underwater archaeological project within Europe in accordance with European legislation (Treaty of Valetta (1992). Summarily the project has utilised a down scaling approach to localise archaeological sites at a large scale regional level. This has involved using innovative satellite imagery to obtain seamless topography maps over coastal areas and the seabed (accurate to a depth of 6m) as well as the development of a 3D sub bottom profiler to look within the seabed. Results obtained from the downscaling approach at the study areas in the project (Greece and Denmark) have enabled geological models to be developed inorder to work towards predictive modelling of where submerged prehistoric sites may be encountered. Once sites have been located an upscaling approach has been taken to assessing an individual site and the materials on and within it in order to better understand the state of preservation and dynamic conditions of a site and how it can best be preserved through in situ preservation or excavation. This has involved the development of equipment to monitor the seabed environment (open water and in sediments), equipment for sampling sediments and assessing the state of preservation of wood, once of the common materials on archaeological sites. The guidelines and all information and experiences obtained during the course of the project will be utilised to enhance and develop existing legislation and best practice for mapping and preserving Europe's underwater and coastal heritage. The project started in September 2012 and finished at the end of August 2015 and the aim of the paper is to give a brief introduction to the results of the project. Further information on the project is available at www.sasmap.eu.
Bohm B.,National Museum of Denmark |
Ryhl-Svendsen M.,National Museum of Denmark
Energy and Buildings | Year: 2011
A finite element model of an unheated museum store has been developed for simulating the influence of the building envelope, the wall thickness and the thermal interaction with the surrounding ground on indoor temperature of the store. The question of whether to build the store with high thermal mass or with well-insulated walls with no thermal mass is addressed. The influence from excess humidity entering the store through cracks in the building envelope is also discussed. Finally, ways to stabilize the store temperature by improved design, such as additional insulation of the foundation, will be analysed. The simulations are compared with measurements in a museum store in Ribe, Denmark. © 2011 Elsevier B.V.
Matthiesen H.,National Museum of Denmark
Quaternary International | Year: 2014
In situ preservation is increasingly a preferred option for managing archaeological remains, as there is a wish to preserve some undisturbed remains for later generations to investigate using new methods and asking new questions. However, in situ preservation is only a viable option if the remains are well protected and are not undergoing rapid decay, and it requires a detailed knowledge of decay processes and rates. For instance it is well established that the presence of water is of paramount importance for the preservation of organic material, and there are several examples where archaeological remains in wetlands have been preserved under waterlogged conditions for thousands of years, only to be degraded within a few years or decades after drainage of the wetland. What is less clear is the importance of the water quality, and exactly how much water is necessary to prevent or minimize decay. Thus, for the management of archaeological sites it is necessary to develop tools and methods that allow us to discover ongoing decay as fast as possible. Furthermore, in order to prioritize between excavation, in situ preservation and mitigation the decay rate should be evaluated on a quantitative scale to determine if the archaeological remains can be preserved for centuries, decades or only a few years under different conditions. This is a challenging task as archaeological sites and materials are often heterogeneous and have been subjected to different site formation processes. This paper describes different approaches that may be used for determining decay rates of archaeological remains, and discusses their advantages and disadvantages. It is argued that it is necessary to combine several approaches to estimate decay rates and reach a reliable understanding of the decay. © 2014 Elsevier Ltd and INQUA.