10 December 2023 The Future is the Product of the Past

Roman-era Mixers and Millstones Made with Geology in Mind

A study on stone tools from an outpost of the Roman Empire has found that for ancient bakers and millers, having the right tools was a matter of geology. 

A team of geoscientists and archaeologists made the discovery by analyzing samples of the tools at a University of Texas at Austin geology lab, finding that dough mixing vats and millstones from Roman-era ruins of Volubilis, a city in Morocco, were made from specific rock types that probably improved each tool’s function.

Furthermore, the researchers determined that the stones were sourced locally, a discovery that challenges a theory that some millstones had been imported from afar. It also means that the craftspeople who made the tools may have received input directly from the workers who used them. 

“It is interesting because it is a very local source and seemingly from one source,” said Jared Benton, a study co-author and an assistant professor at Old Dominion University who studies trade between Roman-era workshops. “One wonders if there’s not a group of bakers that are coming together and saying let’s buy our stuff from this one quarry, or maybe there’s just one guy who [sells the stones], and that’s it.”  

The results were published in the Journal of Archaeological Science: Reports

Derek Weller, a postdoctoral researcher at the University of Tokyo’s Earthquake Research Institute, led the study. Additional co-authors include Omero “Phil” Orlandini, research associate and manager of the Electron Microbeam Laboratory at the UT Jackson School of Geosciences; Lauren LoBue and Scott Culotta, both undergraduates at the Jackson School; and Christy Schirmer, a graduate student in UT’s Department of Classics.  

An olive millstone in Volubilis. Research assistant Drew Messing holds a tool for scale. Photo: Jared Benton.
An olive millstone in Volubilis. Research assistant Drew Messing holds a tool for scale. Photo: Jared Benton.

The study got its start in early 2020 when Schirmer showed up at Orlandini’s lab with a box of rocks. They were pieces of the stone tools that she and Benton had collected from the tools in Volubilis – and they were curious about were learning more about their geological makeup could lead them. 

“They sort of look the same when they’re in tool form, but as soon as we started looking, it was clear that they were completely different,” Orlandini said. 

Orlandini got LoBue and Culotta on the case. The undergraduates put all 16 samples through a detailed scientific workup to determine their composition at the geochemical level.  

Their research revealed a rock type for each tool type. Grain millstones were made from vesicular basalts (a volcanic stone full of sharp-edged pores); olive mills were made from clastic, fossiliferous limestone (a limestone containing fragments of other rocks and small fossil shells); and dough mixers were made from limestone with no clastic material or fossils.  

 The study notes how the rocks’ attributes relate to each tool’s function. For example, the pores in the basalt may have helped provide fresh edges that could help grind wheat into flour as the stone was worn down. 

 Weller also used the geochemical data to determine that all the stones came from sources near Volubilis. Limestone is plentiful in the region, and two limestone quarries were already known to be active during the Roman era near Volubilis. But archaeologists previously thought the basalt – which Weller found came from the nearby Middle Atlas Mountains – was imported from Italy.  

In addition, the research found that each rock type came from a single location rather than sourced from different places around Volubilis. Benton said this suggests that a single supplier for each stone type might have been meeting all demand in the city and getting input from local people.   

Elizabeth Fentress, an archaeologist specializing in Roman settlements in North Africa, said that the study is a great example of collaborative research.  

 “It is hardly the only collaboration between geologists and archaeologists, but an excellent one,” she said. “The key is, as here, that the archaeologists ask the right questions and use their knowledge to interpret the answers.”

THE UNIVERSITY OF TEXAS AT AUSTIN

Cover Photo: The ruins of Volubilis, a city in Morocco that was part of the Roman Empire. Photo: Sergio Morchon/ Flickr

Related Articles

11,000-Year-Old LSU Campus Mounds Are Oldest Known Human-Made Structures In North America

23 August 2022

23 August 2022

According to new research published in the American Journal of Science, two six-meter (20-foot) high mounds on the campus of...

A Roman tomb where magical nails were used to fend off the ‘restless dead’ has been discovered in Türkiye

15 March 2023

15 March 2023

In the ancient city of Sagalassos in southwestern Türkiye, archaeologists have identified an unusual burial practice from the early Roman...

Part of The ‘Missing Link’ in Human Migration may have been Found in Kaldar Cave

3 April 2021

3 April 2021

Kaldar cave is an important archaeological site that provides evidence for the transition from the Middle and Upper Paleolithic Ages...

Archaeologists discover bones of a woman who lived 14,000 years ago at a site in The Iberian Peninsula

13 August 2021

13 August 2021

Archaeologists have discovered the bones of a lady who lived 14,000 years ago, the earliest traces of a modern burial...

The Earliest Evidence of a Domesticated Dog in the Arabian Peninsula

9 April 2021

9 April 2021

Dogs have been the best friend of humans since ancient times. Although it is not known exactly when dogs were...

New Huge Viking-age boat grave discovered by Radar in Norway

12 April 2022

12 April 2022

Archaeologists have located a boat grave from the Viking Age near Øyesletta in Norway during a ground-penetrating radar (GPR) survey....

The earliest known depiction of biblical heroines Jael and Deborah was discovered at a Jewish synagogue in Israel

8 August 2022

8 August 2022

The earliest known depiction of biblical heroines Jael and Deborah was discovered at a Jewish synagogue at Huqoq in Israel,...

Trian Fountain to Be Revived After 1900 Years

17 April 2021

17 April 2021

The Trian fountain in the ancient city of Laodikeia in Denizli will be revived after 1900 years. CHP’s Merkezefendi Municipality...

Found in Spain a poem by Virgil engraved in a Roman amphora

22 June 2023

22 June 2023

Archaeologists have deciphered a verse by Virgil, the greatest poet of Rome’s Golden Age, carved into the clay of a...

The Nightmare of the Roman Soldiers “Carnyx”

9 July 2023

9 July 2023

The Carnyx was a brass musical instrument used as a psychological weapon of war by the ancient Celts between 300...

A Dancing Muses statue 2175 years old was found in the ancient city of Stratonikeia, known as the city of eternal loves

7 December 2023

7 December 2023

The latest discovery in the ongoing excavations in the Ancient City of Stratonikeia, known as the city of eternal loves...

World’s Oldest Customer Complaint “at 3800 Years Old”

4 February 2021

4 February 2021

When we are not satisfied with the product we receive, what almost all of us do is complain about the...

At Ostrowite, archaeologists have discovered a high-status burial dating back almost a thousand years

2 January 2022

2 January 2022

Archaeologists have discovered a burial chamber in Ostrowite, in Poland’s Pomeranian Voivodeship, containing several high-status grave goods from the 11th...

The Roman villa in North Yorkshire is described as the first of its kind

14 April 2021

14 April 2021

A Roman villa has been found at a construction site in North Yorkshire, considered the first of its kind. Remains...

483 Celtic gold coins worth several million euros stolen from German museum

23 November 2022

23 November 2022

A huge horde of ancient gold coins dating back to 100 BC was stolen from the Celtic and Roman Museum...