stone age

These scientists built their own Stone Age tools to figure out how they were used

hands-on experiments —

Telltale fractures and microscopic wear marks should be applicable to real artifacts.

Jennifer Ouellette – Mar 9, 2024 7: 50 pm UTC

Enlarge / Testing replica Stone Age tools with a bit of wood-scraping.

A. Iwase et al., 2024/Tokyo Metropolitan University

When Japanese scientists wanted to learn more about how ground stone tools dating back to the Early Upper Paleolithic might have been used, they decided to build their own replicas of adzes, axes, and chisels and used those tools to perform tasks that might have been typical for that era. The resulting fractures and wear enabled them to develop new criteria for identifying the likely functions of ancient tools, according to a recent paper published in the Journal of Archaeological Science. If these kinds of traces were indeed found on genuine Stone Age tools, it would be evidence that humans had been working with wood and honing techniques significantly earlier than previously believed.

The development of tools and techniques for woodworking purposes started out simple, with the manufacture of cruder tools like the spears and throwing sticks common in the early Stone Age. Later artifacts dating back to Mesolithic and Neolithic time periods were more sophisticated, as people learned how to use polished stone tools to make canoes, bows, wells, and to build houses. Researchers typically date the emergence of those stone tools to about 10,000 years ago. However, archaeologists have found lots of stone artifacts with ground edges dating as far back as 60,000 to 30,000 years ago. But it’s unclear how those tools might have been used.

So Akira Iwase of Tokyo Metropolitan University and co-authors made their own replicas of adzes and axes out of three raw materials common to the region between 38,000 and 30,000 years ago: semi-nephrite rocks, hornfels rocks, and tuff rocks. They used a stone hammer and anvil to create various long oval shapes and polished the edges with either a coarse-grained sandstone or a medium-grained tuff. There were three types of replica tools: adze-types, with the working edge oriented perpendicular to the long axis of a bent handle; axe-types, with a working edge parallel to the bent handle’s long axis; and chisel-types, in which a stone tool was placed at the end of a straight handle.

Enlarge / Testing various replicas of Stone Age tools for different uses: A, tree-felling; B, wood-adzing; C, wood-scraping; D, fresh bone-adzing; E, dry hide-scraping; F, disarticulation of a joint.

A. Iwase et al., 2024/Tokyo Metropolitan University

Then it was time to test the replica tools via ten different usage experiments. For instance, the authors used axe-type tools to fell Japanese cedar and maple trees in north central Honshu, as well as a forest near Tokyo Metropolitan University. Axe-type and adze-type tools were used to make a dugout canoe and wooden spears, while adze-type tools and chisel-type tools were used to scrape off the bark of fig and pine. They scraped flesh and grease from fresh and dry hides of deer and boar using adze-type and chisel-type tools. Finally, they used adze-type tools to disarticulate the femur and tibia joints of deer hindlimbs.

The team also conducted several experiments in which the tools were not used to identify accidental fractures not related to any tool-use function. For instance, flakes and blades can break in half during flint knapping; transporting tools in, say, small leather bags can cause microscopic flaking; and trampling on tools left on the ground can also modify the edges. All these scenarios were tested. All the tools used in both use and non-use experiments,ents were then examined for both macroscopic and microscopic traces of fracture or wear.

Enlarge / Traces left by tree-felling experiments on replica stone age tools. Characteristic macroscopic (top) and microscopic (bottom) traces might be used to determine how stone edges were used.

Tokyo Metropolitan University

The results: they were able to identify nine different types of macroscopic fractures, several of which were only seen when making percussive motions, particularly in the case of felling trees. There were also telltale microscopic traces resulting from friction between the wood and stone edge. Cutting away at antlers and bones caused a lot of damage to the edges of adze-like tools, creating long and/or wide bending fractures. The tools used for limb disarticulation caused fairly large bending fractures and smaller flaking scars, while only nine out of 21 of the scraping tools showed macroscopic signs of wear, despite hundreds of repeated strokes.

The authors concluded that examining macroscopic fracture patterns alone are insufficient to determine whether a given stone tool had been used percussively. Nor is any resulting micropolish from abrasion an unambiguous indicator on its own, since scraping motions produce a similar micropolish. Combining the two, however, did yield more reliable conclusions about which tools had been used percussively to fell trees, compared to other uses, such as disarticulation of bones.

DOI: Journal of Archaeological Science, 2024. 10.1016/j.jas.2023.105891 (About DOIs).

Scientists found a Stone Age megastructure submerged in the Baltic Sea

Archaeology, megastructures, Science, stone age / Blake Jones / February 14, 2024

They built a wall —

“Blinkerwall” may have been a “desert kite,” used to channel and hunt reindeer.

Jennifer Ouellette – Feb 13, 2024 10: 18 pm UTC

Enlarge / Graphical reconstruction of a Stone Age wall as it may been used: as a hunting structure in a glacial landscape.

Michał Grabowski

In 2021, Jacob Geersen, a geophysicist with the Leibniz Institute for Baltic Sea Research in the German port town of Warnemünde, took his students on a training exercise along the Baltic coast. They used a multibeam sonar system to map the seafloor about 6.2 miles (10 kilometers) offshore. Analyzing the resulting images back in the lab, Geersen noticed a strange structure that did not seem like it would have occurred naturally.

Further investigation led to the conclusion that this was a manmade megastructure built some 11,000 years ago to channel reindeer herds as a hunting strategy. Dubbed the “Blinkerwall,” it’s quite possibly the oldest such megastructure yet discovered, according to a new paper published in the Proceedings of the National Academy of Sciences—although precisely dating these kinds of archaeological structures is notoriously challenging.

As previously reported, during the 1920s, aerial photographs revealed the presence of large kite-shaped stone wall mega-structures in deserts in Asia and the Middle East that most archaeologists believe were used to herd and trap wild animals. More than 6,000 of these “desert kites” have been identified as of 2018, although very few have been excavated. Last year, archaeologists found two stone engravings—one in Jordan, the other in Saudi Arabia—that they believe represent the oldest architectural plans for these desert kites.

However, these kinds of megastructures are almost unknown in Europe, according to Geersen et al., because they simply didn’t survive the ensuing millennia. But the Baltic Sea basins, which incorporate the Bay of Mecklenburg where Geersen made his momentous discovery, are known to harbor a dense population of submerged archaeological sites that are remarkably well-preserved—like the Blinkerwall.

Enlarge / Morphology of the southwest–northeast trending ridge that hosts the Blinkerwall and the adjacent mound.

J. Geersen et al., 2024

After they first spotted the underwater wall, Geeren enlisted several colleagues to lower a camera down to the structure. The images revealed a neat row of stones forming a wall under 1 meter (3.2 feet) in height. There are 10 large stones weighing several tons, spaced at intervals, and connected by more than 1,600 smaller stones (less than 100 kilograms or 220 pounds). “Overall, the ten heaviest stones are all located within regions where the stonewall changes is strike direction,” the authors wrote. The length of the wall is 971 meters (a little over half a mile).

They concluded that the wall didn’t form through natural processes like a moving glacier or a tsunami, especially given the careful placement of the larger stones wherever the wall zigs or zags. It is more likely the structure is manmade and built over 10,000 years ago, although the lack of other archaeological evidence like stone tools or other artifacts makes dating the site difficult. They reasoned that before then, the region would have been covered in a sheet of ice. The immediate vicinity would have had plenty of stones laying about to build the Blinkerwall. Rising sea levels then submerged the structure until it was rediscovered in the 21st century. This would make the Blinkerwall among the oldest and largest Stone Age megastructures in Europe.

As for why the wall was built, Geeren et al. suggest that it was used as a desert kite similar to those found in Asia and the Middle East. There are usually two walls in a desert kite, forming a V shape, but the Blinkerwall happens to run along what was once a lake. Herding reindeer into the lake would have slowed the animals, making them easier to hunt. It’s also possible that there is a second wall hidden underneath the sediment on the seafloor. “When you chase the animals, they follow these structures, they don’t attempt to jump over them,” Geersen told The Guardian. “The idea would be to create an artificial bottleneck with a second wall or with the lake shore.”

Enlarge / 3D model of a section of the Blinkerwall adjacent to the large boulder at the western end of the wall.

Philipp Hoy, Rostock University

A similar submerged stone-walled drive lane, known as “Drop 45,” is located in Lake Huron in the US; divers found various lithic artifacts around the drive lane, usually in circular spots that could have served as hunting blinds. The authors suggest that the larger blocks of the Blinkerwall could also have been hunting blinds, although further archaeological surveys will be needed to test this hypothesis.

“I think the case is well made for the wall as an artificial structure built to channel movements of migratory reindeer,” archaeologist Geoff Bailey of the University of York, who is not a co-author on the paper, told New Scientist. Vincent Gaffney of the University of Bradford concurred. “Such a find suggests that extensive prehistoric hunting landscapes may survive in a manner previously only seen in the Great Lakes,” he said. “This has very great implications for areas of the coastal shelves which were previously habitable.”

PNAS, 2024. DOI: 10.1073/pnas.2312008121 (About DOIs).

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