Over the course of his 54-year career, American archaeologist Bruce Bradley, now a professor emeritus at the University of Exeter, estimates he has produced 100 replicas of ancient artifacts for exhibitions at British museums and thousands for other purposes. His job is to recreate objects made by our human ancestors thousands of years ago. Using similar techniques and tools to those used in the past, he produces copies of the original pieces from materials such as animal horns, metal points, and chipped stones.
One of Bradley’s biggest challenges came in 2017, following an invitation from the Museum of Cardiff. His brief was to recreate a set of thin bifacial arrowheads found in a Bronze Age burial pit. The original artifacts were made by people who lived at the Breach Farm archaeological site in South Wales about four millennia ago, between 1950 BC and 1750 BC. Archaeologists began excavating the area in 1938 and have been studying it ever since.
In the cover article of July’s issue of the scientific journal Ethnoarchaeology, Bradley, with a colleague from the USA and two from Brazil, describe the work involved in making the replicas of 13 chipped stone arrowheads from this Welsh site and a curious discovery they made along the way. Half of the original points were made using a technique and type of rock found in the south of the British Isles: black flint. The other half were produced using another method and material, both from northwest France: a silicified sandstone called Greensand chert.
“Only one arrowhead did not fit this pattern,” says Colombian-Brazilian archaeologist João Carlos Moreno, lead author of the study and now a professor at the Federal University of Rio Grande (FURG). At the time of his work at the Welsh site, Moreno was a visiting researcher at the University of Exeter as part of his PhD at the National Museum of the Federal University of Rio de Janeiro and was invited to join the team studying the arrowheads. Despite being made of flint from the UK, tip number 10 was made using a technique typical of flintknappers from Armorica, an ancient region that today encompasses the northwest of France.
This hybrid projectile, produced from British material but using the Armorican method, reinforces the theory that cultural exchanges occurred between the two sides of the English Channel, which separates the British Isles from continental Europe. Specialist stone knappers crossed the sea, probably transporting stones typical of their region. “People often think that prehistoric human groups were quite isolated, but this is not true,” says archaeologist Mercedes Okumura of the University of São Paulo (USP), another author of the article. “The simple fact that there was this mismatch between the technique and the raw material used to make this point from Breach Farm shows that some kind of exchange was taking place in the region.”
The two arrowhead types have a very similar appearance. Both are triangular and almost as thin as a sheet of paper. Their average length is 3.6 centimeters. They were used in funerary rituals, rather than for combat or hunting. In addition to being made of different materials, some small differences are noticeable. The faces of the points made using the Armorican technique are straighter and sharper than those produced by the British method, whose edges are sometimes slightly rounded. Analyses carried out using X-ray fluorescence, a technique that makes it possible to determine the elements of which a rock is composed, suggest that the Greensand chert came from northwest France and the flint came from the British Isles.
Even after repeating the steps employed by the ancient craftsmen at the Welsh site, the experienced Bradley was unable to produce perfect replicas of the original points. His copies were slightly thicker, heavier, and less precisely finished. “This project showed that my efforts fell short of the skills of the ancient flintknappers,” said the British archaeologist in an interview with Pesquisa FAPESP.
According to the study, the points from the Welsh site were made using copper tools to shape the rocks. When used to carve stone, copper tools deteriorate less than others made of horn or bronze. The Armorican technique involved initially shaving a thin flake from a piece of Greensand chert. The knappers then used pressure to gradually wear away the material with the aid of a piece of copper, carving an arrowhead shape.
In the British method, considered less refined, the arrowhead was carved directly into a piece of flint by striking it repeatedly, chipping away at the material by hitting it directly. Fine adjustments were made at the end using pressure techniques.
Archaeologists have evidence that both the Greensand chert and flint were subjected to some form of heat treatment in the Bronze Age to make them more malleable, which would have facilitated the flaking and chipping methods. It is unknown how exactly they heated the rocks at that time—whether the stones were placed in an open fire or buried and “cooked” in a covered stove. In the lab, Bradley chose to heat the rock samples used for the replicas in an electric oven at 210 degrees Celsius (°C) for 4 hours.
“The new study shows how skilled Bronze Age knappers were,” French archaeologist Clément Nicolas, a specialist in the European Bronze Age from the French National Center for Scientific Research (CNRS) who has also published work on the Breach Farm points, said in an interview with Pesquisa FAPESP. Nicolas, however, questions the authors’ claim that Breach Farm arrowheads made of Greensand chert came from rocks in northwestern France. “Identifying the geochemical signature of sedimentary rocks is a highly complex task, especially when it involves a large area covering southern Britain and northern France, where the geology is very similar,” explains the Frenchman.
Nicolas also argues that the two techniques identified in the study may represent different skill levels in the same chain of operations, rather than two different arrowhead production methods used by different peoples in different places. From this other perspective, the theory would be that the most skilled artisans at Breach Farm made points using the pressure technique alone, while those less able used striking first and then pressure. The scientist also points out that while heating the stones makes them easier to shape, other studies have shown that heating is not necessary to make points as thin as those found at the Welsh site. Further research on these arrowheads should attempt to answer these remaining questions.
MORENO, J. C. et al. Two technological traditions of bifacial points from the Breach Farm site, Wales: An interdisciplinary analysis of lithic technology integrating experimental replication, X-ray fluorescence, and geometric morphometry. Ethnoarchaeology. July 5, 2022.