Monday, November 30, 2020

Cereal, olive and vine pollen reveal market integration in Ancient Greece


A new interdisciplinary study indicates agricultural market integration centuries before Roman conquest, suggesting the mechanisms that led to the Anthropocene began much earlier than assumed


In the field of economics, the concept of a market economy is largely considered a modern phenomenon. Influential economists such as Karl Marx and Max Weber, for example, argued that although markets existed in antiquity, economies in which structures of production and distribution responded to the laws of supply and demand developed only as recently as the 19th century. A recent study by an international team of researchers, including Adam Izdebski of the Max Planck Institute for the Science of Human History, uses palynology - the study of pollen remains extracted from cored sediments - to challenge this belief and provide evidence for an integrated market economy existing in ancient Greece.

Market integration began earlier than assumed

Using publicly available data from the European Pollen Database, as well as data from other investigators, researchers analyzed pollen assemblages from 115 samples taken from six sites in southern Greece to measure landscape change. Using radiocarbon dating to tie their measurements to historical time, researchers followed the change in percentage values for individual plant taxa between 1000 BCE and 600 CE and observed a decrease in pollen from cereals, a staple of the ancient Greek diet, during a period of apparent population growth. This decrease occurred at the same time as an increase in the proportion of olive and vine pollen. These trends raise an important question: why would local producers chose to plant olives and vines instead of cereal grains, when the demand for this staple food must have been high and mounting?

In the current study, researchers argue that pollen data from southern Greece reveals an export economy based on cash cropping as early as the Archaic period, primarily through olive cultivation. Although archeological evidence from these periods documents the movement of goods, quantifiable data on market integration and structural changes in agricultural production have been very limited. "In this paper," says lead author Adam Izdebski, "we introduce pollen records as a new source of quantitative data in ancient economic history."

From mud to markets: Integrated scientific approaches reveal an integrated ancient economy

Before arriving at their conclusions, researchers compared the trends they observed in the pollen data with three other sources of data in an instance of pioneering scientific research. First, researchers observed a decrease in pollen from uncultivated landscapes corresponding with each increase in settlement numbers. This correlation between the number of settlements and the exploitation of the land supports the methodology of the study and indicates the potential of palynology for future studies in a variety of scientific disciplines.

Researchers then looked for evidence of increased trade activity in Mediterranean shipwrecks, which are routinely used to estimate maritime trade and overall economic activity. After restricting their search to wrecks from the appropriate period and region, scientists observed trends in shipwrecks consistent with trends found in cereal, olive, and vine pollen. Both sources of data suggest an economic boom in the 1st and 2nd century CE, a decline in the 4th and 5th century, and a smaller boom in the 6th century.

Finally, researchers examined trends in the presence of large-scale oil and wine presses in the Mediterranean. The presence of these machines, although not located in Greece, indicates a pattern of broad economic trends in the region and changing incentives for the production of large quantities of olive oil and wine. Again, the researchers found that trends in archaeological findings of oil and wine presses were consistent with trends in cereal, olive, and vine pollen.

As the emergence of integrated markets and capitalist economies of the early modern era is believed to have been at the roots of the Anthropocene, the current epoch in which humanity has become a major geological force, the current study shows that the structural developments that occurred on a large scale through European colonization from the 15th century onward were possible several thousand years before.

Friday, November 27, 2020

Neanderthal thumbs better adapted to holding tools with handles

Neanderthal thumbs were better adapted to holding tools in the same way that we hold a hammer, according to a paper published in Scientific Reports. The findings suggest that Neanderthals may have found precision grips -- where objects are held between the tip of the finger and thumb -- more challenging than power 'squeeze' grips, where objects are held like a hammer, between the fingers and the palm with the thumb directing force.

Using 3D analysis, Ameline Bardo and colleagues mapped the joints between the bones responsible for movement of the thumb -- referred to collectively as the trapeziometacarpal complex -- of five Neanderthal individuals, and compared the results to measurements taken from the remains of five early modern humans and 50 recent modern adults.

The authors found covariation in shape and relative orientation of the trapeziometacarpal complex joints that suggest different repetitive thumb movements in Neanderthals compared with modern humans. The joint at the base of the thumb of the Neanderthal remains is flatter with a smaller contact surface, and better suited to an extended thumb positioned alongside the side of the hand. This thumb posture suggests the regular use of power 'squeeze' grips, like the ones we now use to hold tools with handles. In comparison, these joint surfaces are generally larger and more curved in recent modern human thumbs, an advantage when gripping objects between the pads of the finger and thumb, known as a precision grip.

Although the morphology of the studied Neanderthals is better suited for power 'squeeze' grips, they would still have been capable of precision hand postures, but would have found this more challenging than modern humans, according to the authors.

Comparison of fossil morphology between the hands of Neanderthals and modern humans may provide further insight into the behaviours of our ancient relatives and early tool use.

Thursday, November 26, 2020

The economic and cultural aspects of raising turkeys to supply feathers in the ancient Southwest.

 The ancient inhabitants of the American Southwest used around 11,500 feathers to make a turkey feather blanket, according to a new paper in the Journal of Archaeological Science: Reports. The people who made such blankets were ancestors of present-day Pueblo Indians such as the Hopi, Zuni and Rio Grande Pueblos.

A team led by Washington State University archaeologists analyzed an approximately 800-year-old, 99 x 108 cm (about 39 x 42.5 inches) turkey feather blanket from southeastern Utah to get a better idea of how it was made. Their work revealed thousands of downy body feathers were wrapped around 180 meters (nearly 200 yards) of yucca fiber cord to make the blanket, which is currently on display at the Edge of the Cedars State Park Museum in Blanding, Utah.

The researchers also counted body feathers from the pelts of wild turkeys purchased from ethically and legally compliant dealers in Idaho to get an estimate of how many turkeys would have been needed to provide feathers for the blanket. Their efforts show it would have taken feathers from between four to 10 turkeys to make the blanket, depending on the length of feathers selected.

"Blankets or robes made with turkey feathers as the insulating medium were widely used by Ancestral Pueblo people in what is now the Upland Southwest, but little is known about how they were made because so few such textiles have survived due to their perishable nature," said Bill Lipe, emeritus professor of anthropology at WSU and lead author of the paper. "The goal of this study was to shed new light on the production of turkey feather blankets and explore the economic and cultural aspects of raising turkeys to supply the feathers."

Clothing and blankets made of animal hides, furs or feathers are widely assumed to have been innovations critical to the expansion of humans into cold, higher latitude and higher elevation environments, such as the Upland Southwest of the United States where most of the early settlements were at elevations above 5,000 feet.

Previous work by Lipe and others shows turkey feathers began to replace strips of rabbit skin in construction of twined blankets in the region during the first two centuries C.E. Ethnographic data suggest the blankets were made by women and were used as cloaks in cold weather, blankets for sleeping and ultimately as funerary wrappings.

"As ancestral Pueblo farming populations flourished, many thousands of feather blankets would likely have been in circulation at any one time," said Shannon Tushingham, a co-author on the study and assistant professor of anthropology at WSU. "It is likely that every member of an ancestral Pueblo community, from infants to adults, possessed one."

Another interesting finding of the study was the turkey feathers used by the ancestral Pueblo people to make garments were most likely painlessly harvested from live birds during natural molting periods. This would have allowed sustainable collection of feathers several times a year over a bird's lifetime, which could have exceeded 10 years. Archeological evidence indicates turkeys were generally not used as a food source from the time of their domestication in the early centuries C.E. until the 1100s and 1200s C.E., when the supply of wild game in the region had become depleted by over-hunting.

Prior to this period, most turkey bones reported from archaeological sites are whole skeletons from mature birds that were intentionally buried, indicating ritual or cultural significance. Such burials continued to occur even after more turkeys began to be raised for food.

"When the blanket we analyzed for our study was made, we think in the early 1200s C.E., the birds that supplied the feathers were likely being treated as individuals important to the household and would have been buried complete," Lipe said. "This reverence for turkeys and their feathers is still evident today in Pueblo dances and rituals. They are right up there with eagle feathers as being symbolically and culturally important."

In the long run, the researchers said their hope is the study will help people appreciate the importance of turkeys to Native American cultures across the Southwest.

"Turkeys were one of the very few domesticated animals in North America until Europeans arrived in the 1500s and 1600s," Tushingham said. "They had and continue to have a very culturally significant role in the lives of Pueblo people, and our hope is this research helps shed light on this important relationship."

Monday, November 23, 2020

Ancient people relied on coastal environments to survive the Last Glacial Maximum

Humans have a longstanding relationship with the sea that spans nearly 200,000 years. Researchers have long hypothesized that places like coastlines helped people mediate global shifts between glacial and interglacial conditions and the impact that these changes had on local environments and resources needed for their survival. Coastlines were so important to early humans that they may have even provided key routes for the dispersal of people out of Africa and across the world.

Two new multidisciplinary studies published in the journals Quaternary Science Reviews and Quaternary Research document persistent human occupation along the South African eastern seaboard from 35,000 years ago to 10,000 years ago. In this remote, and largely unstudied, location -- known as the "Wild Coast" -- researchers have used a suite of cutting-edge techniques to reconstruct what life was like during this inclement time and how people survived it.

The research is being conducted by an international and interdisciplinary collaboration of scientists studying coastal adaptations, diets and mobility of hunter-gatherers across glacial and interglacial phases of the Quaternary in coastal South Africa. The research team is led by Erich Fisher, Institute of Human Origins at Arizona State University; Hayley Cawthra with the South Africa Council for Geoscience and Nelson Mandela University; Irene Esteban, University of the Witwatersrand; and Justin Pargeter, New York University.

Together, these scientists have been leading excavations at the Mpondoland coastal rock shelter site known as Waterfall Bluff for the last five years. These excavations have uncovered evidence of human occupations from the end of the last ice age, approximately 35,000 years ago, through the complex transition to the modern time, known as the Holocene. Importantly, these researchers also found human occupations from the Last Glacial Maximum, which lasted from 26,000 to 19,000 years ago.

The Last Glacial Maximum was the period of maximum global ice volume, and it affected people and places around the world. It led to the formation of the Sahara desert and caused major reductions in Amazonian rainforest. In Siberia, the expansion of polar ice caps led to drops in global sea levels, creating a land bridge that allowed people to cross in to North America.

In southern Africa, archaeological records from this globally cold and dry time are rare because there were widespread movements of people as they abandoned increasingly inhospitable regions. Yet records of coastal occupation and foraging in southern Africa are even rarer. The drops in sea level during the Last Glacial Maximum and earlier glacial periods exposed an area on the continental shelf across southern Africa nearly as large as the island of Ireland. Hunter-gatherers wanting to remain near coastlines during these times had to trek out onto the exposed continental shelf. Yet these records are gone now, either destroyed by rising sea levels during warmer interglacial periods or submerged under the sea.

The research team -- the Mpondoland Paleoclimate, Paleoenvironment, Paleoecology, and Paleoanthropology Project (P5 Project) -- has hypothesized that places with narrow continental shelfs may preserve these missing records of glacial coastal occupation and foraging.

"The narrow shelf in Mpondoland was carved when the supercontinent Gondwana broke up and the Indian Ocean opened. When this happened, places with narrow continental shelfs restricted how far and how much the coastline would have changed over time," said Hayley Cawthra.

In Mpondoland, a short section of the continental shelf is only 10 kilometers wide.

"That distance is less than how far we know past people often traveled in a day to get sea foods, meaning that no matter how much the sea levels dropped anytime in the past, the coastline was always accessible from the archaeological sites we have found on the modern Mpondoland coastline. It means that past people always had access to the sea, and we can see what they were doing because the evidence is still preserved today," said Erich Fisher.

The oldest record of coastal foraging, which has also been found in southern Africa, shows that people relied on coastlines for food, water and move favorable living conditions over tens of thousands of years.

In the study published in the journal Quaternary Research, led by Erich Fisher, a multidisciplinary team of researchers documents the first direct evidence of coastal foraging in Africa during a glacial maximum and across a glacial/interglacial transition.

According to Fisher, "The work we are doing in Mpondoland is the latest in a long line of international and multidisciplinary research in South Africa revealing fantastic insights into human adaptations that often occurred at or near coastlines. Yet until now, no one had any idea what people were doing at the coast during glacial periods in southern Africa. Our records finally start to fill in these longstanding gaps and reveal a rich, but not exclusive, focus on the sea. Interestingly, we think it may have been the centralized location between land and sea and their plant and animal resources that attracted people and supported them amid repeated climatic and environmental variability."

To date this evidence, P5 researchers collaborated with South Africa's iThemba LABS and researchers at the Centre for Archaeological Science of the University of Wollongong to develop one of the highest-resolution chronologies at a southern Africa Late Pleistocene site, showing persistent human occupation and coastal resource use at Waterfall Bluff from 35,000 years ago to 10,000 years ago. This evidence, in the form of marine fish and shellfish remains, shows that prehistoric people repeatedly sought out dense and predictable seafoods.

This finding complements the results of a companion study published in the journal Quaternary Science Reviews, where paleobotanists and paleoclimatologists, led by Irene Esteban, used different lines of evidence to investigate interactions between prehistoric people's plant-gathering strategies and climate and environmental changes over the last glacial/interglacial phase. This is the first multiproxy study in South Africa that combines preserved plant pollen, plant phytoliths, macro botanical remains (charcoal and plant fragments) and plant wax carbon and hydrogen isotopes from the same archaeological archive.

According to Irene Esteban, "It is not common to find such good preservation of different botanical remains, both of organic and inorganic origin, in the archaeological record."

Each one of these records preserves a slightly different window to the past. It let the researchers compare different records to study how each one formed and what they represented, both individually and together.

"Ultimately," said Esteban, "it allowed us to study interactions between hunter-gatherer plant-gathering strategies and environmental changes across a glacial-interglacial transition."

Today, Mpondoland is characterized by afrotemperate and coastal forests as well as open woodlands that are interspersed with grasslands and wetlands. Each of these vegetation types supports different plant and animal resources. One of the key findings of this study is that these vegetation types persisted across glacial and interglacial periods albeit in varying amounts due to changes in sea levels, rainfall and temperature. The implication is that people living in Mpondoland in the past had access to an ever present and diverse suite of resources that let them survive here when they couldn't in many other places across Africa.

Importantly, this study showed that people who lived at Waterfall Bluff collected wood from coastal vegetation communities during both glacial and interglacial phases. It is another link to the coastline for the people living at Waterfall Bluff during the Last Glacial Maximum. In fact, the exceptional quality of the archaeological and paleoenvironmental records demonstrates that those hunter-gatherers targeted different, but specific, coastal ecological niches all the while collecting terrestrial plant and animal resources from throughout the broader landscape and maintaining links to highland locales inland.

"The rich and diverse resource bases targeted by Mpondoland's prehistoric hunter-gatherers speaks to our species' unique generalist-specialist adaptations," said Justin Pargeter. "These adaptions were key to our species ability to survive wide climate and environmental fluctuations while maintaining long-distance cultural and genetic connections."

Together, these papers enrich our understanding about the adaptive strategies of people facing widespread climatic and environmental changes. They also provide a complementary perspective on hunter-gatherer behavioral responses to environmental shifts that is often biased by ethnographic research on African hunter-gatherers living in more marginal environments. In the case of Mpondoland, it is now evident that at least some people sought out the coast -- probably because it provided centralized access to fresh water as well as both terrestrial and marine plant and animal resources, which supported their daily survival.

According to Esteban and Fisher, "These studies are just a drop in the ocean compared to the richness of the archaeological record we already know is preserved in Mpondoland. We have high expectations about what else we will discover there with our colleagues in South Africa and abroad when we can get back to the field safely in this post-COVID world."

Friday, November 20, 2020

Archaeology: Transition to feudal living in 14th century impacted local ecosystems

The transition from tribal to feudal living, which occurred throughout the 14th century in Lagow, Poland had a significant impact on the local ecosystem, according to a study published in Scientific Reports. The findings demonstrate how historical changes to human society and economies may have changed local environments.

Mariusz Lamentowicz and colleagues analysed changes in the composition of plants and pollen in different layers of peat in Pawski Lug, a nature reserve in Western Poland near the village of Lagow. Lagow was founded in the early 13th century and was settled by the Order of St. John of Jerusalem, Knights Hospitaller in 1350 CE.

By analysing the composition of different peat layers, the authors were able to draw conclusions about the conditions that were present when each layer was formed. Based on the presence of beech and hornbeam trees, and water lilies in older, deeper layers, the authors concluded that prior to settlement by the Knights Hospitaller, Pawski Lug consisted of waterlogged land surrounded by pristine forest. The authors suggest that small amounts of charcoal present in the peat indicate that the forest was regularly burned on a small scale by the Slavic tribes that inhabited the area at the time.

Under the Knights Hospitaller, the majority of the land was given to agricultural labourers for farming. The authors found that the prevalence of hornbeam in peat from this era decreased as the abundance of cereals increased, indicating deforestation in favour of the establishment of croplands and meadows around the waterlogged land. The authors propose that deforestation may have affected the groundwater levels of Pawski Lug. Increased abundances of Scots pine trees indicate that this species recolonized the area. As a result, the soil became increasingly acidic, supporting the growth of peat moss which both acidified the habitat and aided peat formation.

The findings illustrate the direct and significant impact the economic transformation of Lagow from a tribal to a feudal society had on the local ecosystem.

Hidden 15th-century text on medieval manuscripts


Imaging system they built as freshmen reveals new information about Otto Ege Collection


Research News




Rochester Institute of Technology students discovered lost text on 15th-century manuscript leaves using an imaging system they developed as freshmen. By using ultraviolet-fluorescence imaging, the students revealed that a manuscript leaf held in RIT's Cary Graphic Arts Collection was actually a palimpsest, a manuscript on parchment with multiple layers of writing.

At the time the manuscript was written, making parchment was expensive, so leaves were regularly scraped or erased and re-used. While the erased text is invisible to the naked eye, the chemical signature of the initial writing can sometimes be detected using other areas of the light spectrum.

"Using our system, we borrowed several parchments from the Cary Collection here at RIT and when we put one of them under the UV light, it showed this amazing dark French cursive underneath," said Zoë LaLena, a second-year imaging science student from Fairport, N.Y., who worked on the project. "This was amazing because this document has been in the Cary Collection for about a decade now and no one noticed. And because it's also from the Ege Collection, in which there's 30 other known pages from this book, it's really fascinating that the 29 other pages we know the location of have the potential to also be palimpsests."

The imaging system was originally built by 19 students enrolled in the Chester F. Carlson Center for Imaging Science's Innovative Freshman Experience, a yearlong, project-based course that has the imaging science, motion picture science, and photographic sciences programs combine their talents to solve a problem.

When RIT switched to remote instruction in March due to the coronavirus outbreak, the students were unable to finish building it, but thanks to a donation from Jeffrey Harris '75 (photographic science and instrumentation) and Joyce Pratt, three students received funding to continue to work on the project over the summer. Those three students--LaLena; Lisa Enochs, a second-year student double majoring in motion picture science and imaging science from Mississauga, Ontario; and Malcom Zale, a second-year motion picture science student from Milford, Mass.--finished assembling the system in the fall when classes resumed and began analyzing documents from the Cary Collection.

Steven Galbraith, curator of the Cary Graphic Arts Collection, said he was excited they discovered the manuscript leaf was a palimpsest because similar leaves have been studied extensively by scholars across the country, but never tested with UV light or fully imaged.

Collector, educator, and historian Otto Ege made leaf collections out of medieval manuscripts that were damaged or incomplete and sold them or distributed them to libraries and special collections across North America, including to the Cary Collection. Galbraith said he's excited because it means that many other cultural and academic institutions with Ege Collection leaves now may have palimpsests in their collection to study.

"The students have supplied incredibly important information about at least two of our manuscript leaves here in the collection and in a sense have discovered two texts that we didn't know were in the collection," said Galbraith. "Now we have to figure out what those texts are and that's the power of spectral imaging in cultural institutions. To fully understand our own collections, we need to know the depth of our collections, and imaging science helps reveal all of that to us."

The students are interested to see if more manuscript leaves from Ege collections across the country are palimpsests. They imaged another Ege Collection leaf at the Buffalo and Erie County Public Library that turned out to be a palimpsest and are reaching out to other curators across the country. As they begin stitching the lost text back together, paleographers can examine the information they contain.

The students have been selected to share their results at the 2021 International Congress on Medieval Studies and also plan to present the project at next year's Imagine RIT: Creativity and Innovation Festival.

Middle Stone Age populations repeatedly occupied West African coast


Excavations at Tiémassas, Senegal, indicate roughly 40,000 years of behavioural continuity, in contrast to other African regions over this period


Research News




Although coastlines have widely been proposed as potential corridors of past migration, the occupation of Africa's tropical coasts during the Stone Age is poorly known, particularly in contrast to the temperate coasts of northern and southern Africa. Recent studies in eastern Africa have begun to resolve this, detailing dynamic behavioural changes near the coast of Kenya during the last glacial phase, but studies of Stone Age occupations along western Africa's coasts are still lacking.

In recent years, anthropological research has begun to investigate the relationship between demographic diversity and patterns of behavioural change. A range of genetic and palaeoanthropological studies have begun to highlight the considerable demographic diversity present in West Africa in the recent past, but archaeological studies of Stone Age sites are still needed to understand how this diversity relates to patterns of behaviour shown in the archaeological record.

"There are plenty of surface sites that have demonstrated the wealth of Stone Age archaeology in West Africa," says Jimbob Blinkhorn of MPI-SHH, "but to characterise patterns of changing behaviour, we need large, excavated stone tool assemblages that we can clearly date to specific periods."

Tiémassas is a Stone Age site with a notable history of research, including surface surveys and early excavations in the mid-20th century, but the lack of systematic study meant it was mired in controversy.

"In the past, Tiémassas has been described as a Middle Stone Age, Later Stone Age or Neolithic site, and resolving between these alternatives has important implications for our understanding of behaviour at the site," says lead author Khady Niang of Université Cheikh Anta Diop de Dakar. "We've reviewed previously collected material from the site, conducted new excavations and analysis of stone tools and combined this with dating studies that make Tiémassas a benchmark example of the Middle Stone Age of West Africa."

Previous research by the team dated a Middle Stone Age occupation at Tiémassas to 45 thousand years ago. The new research extends the timeframe of occupations at the site, with further stone tool assemblages recovered dating to 62 thousand and 25 thousand years ago. Critically, these stone tool assemblages contain technologically distinct types that help to characterise the nature of stone tool production during each occupation phase.

"The Middle Stone Age occupants of Tiémassas employed two distinct technologies - centripetal Levallois and discoidal reduction systems," says Niang. "What is really notable is that the stone tool assemblages are really consistent with one another and form a pattern we can match up with the results of earlier excavations too. Pulled together, the site tells a clear story of startling technological continuity for nearly 40 thousand years."

The results of this new research at Tiémassas consolidate the sparse record of Middle Stone Age occupations of West Africa. Yet, the site's location is distinct from others dated to the Middle Stone Age in the region as it is located close to the coast and at the interface of three ecozones: savannahs, forests and mangroves.

"Our new work at Tiémassas offers a neat comparison to recent work on coastal occupations in eastern Africa. They span roughly the same timeframe, have similar ecological characteristics, and are found along tropical coasts," says Blinkhorn. "But the continuity in behaviour we see at Tiémassas stands in stark contrast to the technological changes observed in eastern Africa, and this reflects a similar pattern seen in genetic and palaeoanthropological studies of enduring population structure in West Africa."

As director of fieldwork for the 'Lise Meitner' Pan-African Evolution research group's aWARE project, Blinkhorn is conducting research in Senegal, Ivory Coast, Benin, and Nigeria, looking for connections between the environments of the past and recent human evolution.

Wednesday, November 18, 2020

Ancestral Puebloans survived from ice melt in New Mexico lava tubes




- For more than 10,000 years, the people who lived on the arid landscape of modern-day western New Mexico were renowned for their complex societies, unique architecture and early economic and political systems. But surviving in what Spanish explorers would later name El Malpais, or the "bad lands," required ingenuity now being explained for the first time by an international geosciences team led by the University of South Florida.

Exploring an ice-laden lava tube of the El Malpais National Monument and using precisely radiocarbon- dated charcoal found preserved deep in an ice deposit in a lava tube, USF geosciences Professor Bogdan Onac and his team discovered that Ancestral Puebloans survived devastating droughts by traveling deep into the caves to melt ancient ice as a water resource.

Dating back as far as AD 150 to 950, the water gatherers left behind charred material in the cave indicating they started small fires to melt the ice to collect as drinking water or perhaps for religious rituals. Working in collaboration with colleagues from the National Park Service, the University of Minnesota and a research institute from Romania, the team published its discovery in "Scientific Reports."

The droughts are believed to have influenced settlement and subsistence strategies, agricultural intensification, demographic trends and migration of the complex Ancestral Puebloan societies that once inhabited the American Southwest. Researchers claim the discovery from ice deposits presents "unambiguous evidence" of five drought events that impacted Ancestral Puebloan society during those centuries.

"This discovery sheds light on one of the many human-environment interactions in the Southwest at a time when climate change forced people to find water resources in unexpected places," Onac said, noting that the geological conditions that supported the discovery are now threatened by modern climate change.

"The melting cave ice under current climate conditions is both uncovering and threatening a fragile source of paleoenvironmental and archaeological evidence," he added.

Onac specializes in exploring the depths of caves around the world where ice and other geological formations and features provide a window to past sea level and climate conditions and help add important context to today's climate challenges.

Their study focused on a single lava tube amid a 40-mile swatch of treacherous ancient lava flows that host numerous lava tubes, many with significant ice deposits. While archaeologists have suspected that some of the surface trails crisscrossing the lava flows were left by ancient inhabitants searching for water, the research team said their work is the earliest, directly dated proof of water harvesting within the lava tubes of the Southwest.

The study characterizes five drought periods over an 800-year period during which Ancestral Puebloans accessed the cave, whose entrance sits more than 2,200 meters above sea level and has been surveyed at a length of 171 meters long and about 14 meters in depth. The cave contains an ice block that appears to be a remnant of a much larger ice deposit that once filled most of the cave's deepest section. For safety and conservation reasons, the National Park Service is identifying the site only as Cave 29.

In years with normal temperatures, the melting of seasonal ice near cave entrances would leave temporary shallow pools of water that would have been accessible to the Ancestral Puebloans. But when the ice was absent or retreated in warmer and dryer periods, the researchers documented evidence showing that the Ancestral Puebloans repeatedly worked their way to the back of the cave to light small fires to melt the ice block and capture the water.

They left behind charcoal and ash deposits, as well as a Cibola Gray Ware pottery shard that researchers found as they harvested a core of ancient ice from the block. The team believes the Ancestral Puebloans were able to manage smoke within the cave with its natural air circulation system by keeping the fires small.

The discovery was an unexpected one, Onac said. The team's original goal in its journey into the lava tube was to gather samples to reconstruct the paleoclimate using ice deposits, which are slowly but steadily melting.

"I have entered many lava tubes, but this one was special because of the amount of charcoal present on the floor in the deeper part of the cave," he said. "I thought it was an interesting topic, but only once we found charcoal and soot in the ice core that the idea to connect the use of ice as a water resource came to my mind."

Unfortunately, researchers are now racing against the clock as modern climate conditions are causing the cave ice to melt, resulting in the loss of ancient climate data. Onac said he recently received support from the National Science Foundation to continue the research in the lava tubes before the geological evidence disappears.

Friday, November 13, 2020

The unique hydraulics in the 2nd century AD Barbegal water mills, the world's first industrial plant


The unique hydraulics in the Barbegal water mills, the world's first industrial plant

An elbow-shaped water flume as a special adaptation for the Barbegal mill complex and a symbol of the ingenuity of Roman engineers

The Barbegal watermills in southern France are a unique complex dating back to the 2nd century AD. The construction with 16 waterwheels is, as far as is known, the first attempt in Europe to build a machine complex on an industrial scale. The complex was created when the Roman Empire was at the height of its power. However, little is known about technological advances, particularly in the field of hydraulics, and the spread of knowledge at the time. A team of scientists led by Professor Cees Passchier from Johannes Gutenberg University Mainz (JGU) has now gained new knowledge about the construction and principle of the water supply to the mills in Barbegal. The research results were published in Scientific Reports.

A mill complex consisting of a total of 16 water wheels in two parallel rows

Watermills were one of the first sources of energy that did not depend on the muscle strength of humans or animals. In the Roman Empire they were used to make flour and sawing stone and wood. As one of the first industrial complexes in European history, the Barbegal watermills are an outstanding example of the development at that time. The mill complex consisted of 16 water wheels in a parallel arrangement of eight wheels each, separated by central buildings and fed by an aqueduct. The upper parts of the complex were destroyed and no traces of the wooden structures have been preserved, which is why the type of mill wheels and how they worked remained a mystery for a long time.

However, carbonate deposits that had formed from the flowing water on the wooden components remained. These were stored in the archaeological museum in Arles and only recently examined in detail. The researchers found an imprint of an unusual, elbow-shaped flume that must have been part of the mill construction. "We combined measurements of the water basins with hydraulic calculations and were able to show that the flume to which this elbow-shaped piece belonged very likely supplied the mill wheels in the lower basins of the complex with water," said Professor Cees Passchier. "The shape of this flume was unknown from other watermills, either from Roman or more recent times. We were therefore puzzled as to why the flume was designed this way and what it was used for."

An elbow-shaped flume as a unique adaptation for the Barbegal mills

At first glance, the team found such a flume unnecessary and even disadvantageous, because it shortens the height from which the water falls onto the mill wheel. "However, our calculations show that the oddly shaped flume is a unique adaptation for the Barbegal mills," explained Passchier. The distribution of the carbonate deposits in the elbow-shaped flume shows that it was inclined slightly backwards against the direction of the current. This created a maximum flow rate in the first, steep leg of the flume, and at the same time the water jet to the mill wheel obtained the correct angle and speed. In the complicated mill system, with small water basins, this unique solution was more efficient than using a traditional, straight water channel. "That shows us the ingenuity of the Roman engineers who built the complex," emphasized Passchier.

"Another discovery was that the wood of the flume was probably cut with a mechanical, water-powered saw, which is possibly the first documented mechanical wood saw - again evidence of industrial activity in ancient times." The research was carried out by a multidisciplinary team of experts in geology, geochemistry, hydraulics, dendrochronology, and archaeology.

The carbonate deposits that formed on the ancient hydraulic structures are an important tool for the researchers for archaeological reconstructions. In an earlier project, the team led by Professor Cees Passchier was able to show that the flour from the Barbegal mills was probably used to make ship biscuits. "The carbonate deposits give us extremely exciting insights into the skills of Roman technicians at a time that can be seen as the direct predecessor of our civilization," added Passchier, Professor of Tectonic Physics and Structural Geology at the JGU Institute of Geosciences from 1993 to 2019, now Senior Research Professor in Geoarchaeology.

Thursday, November 12, 2020

King David-era fort unearthed in Golan Heights

Archaeologists believe the complex was built by the Aramean Kingdom of Geshur.
Ofri Eitan of the Kfar Hanasi pre-military academy next to the engraved stone at the site of the ancient fortified building complex uncovered in the Golan Heights, November 2020. Credit: Tidhar Moav/Israel Antiquities Authority.

Ofri Eitan of the Kfar Hanasi pre-military academy next to the engraved stone at the site of the ancient fortified building complex uncovered in the Golan Heights, November 2020. Credit: Tidhar Moav/Israel Antiquities Authority.

A fortified building complex from the time of King David has been discovered in the southern Golan Heights, the Israel Antiquities Authority (IAA) announced on Wednesday.

The archaeologists who uncovered the complex during IAA excavations in Moshav Haspin assess that it was a fort built by the Kingdom of Geshur (Iron Age, 11th-10th centuries BCE).

According to IAA excavation directors Barak Tzin and Enno Bron, the fortified structure was built strategically on a hilltop above the Nahal El Al Reserve and encompassed by 5-foot-thick walls made of basalt boulders.

“In the excavation, we were astonished to make a rare and exciting find: a large basalt stone with a schematic engraving of two horned figures with outspread arms,” they said.

The IAA noted that a similar horned figure with outstretched arms was discovered on a cultic stone stele—uncovered last year during the Bethsaida Expedition Project, just north of the Sea of Galilee—next to a raised platform adjacent to the city gate. Since the Haspin stone was situated on a shelf next to the fort’s entrance, with two such horned figures depicted on it, the archaeologists speculated that “a person who saw the impressive Bethsaida stele [may have] decided to create a local copy of [it].”

The IAA explained that Bethsaida, a fortified city, is considered by scholars to have been the capital of the Aramean Kingdom of Geshur, which ruled the central and southern Golan 3,000 years ago. The Bible recounts that the kingdom enjoyed diplomatic relations with the House of David and that one of David’s wives was Maacah, the daughter of Talmi, king of Geshur.

According to the IAA, while cities of the Kingdom of Geshur, such as Tel En Gev, Tel Hadar and Tel Sorag, are known to have existed along the shores of the Sea of Galilee, hardly any such sites from the Iron Age have been found in the Golan Heights. The discovery of the Haspin complex is thus spurring new research in the area.