2023-12-01 14:19:52
Research into the mechanical properties of rocks suggested that Paleolithic humans changed their choice of raw materials to suit the morphologies and production techniques of their stone tools. – EIKI SUGA, REIKO MATSUSHITA
MADRID, 1 Dic. (EUROPA PRESS) –
Paleolithic humans selected rocks to make tools because of their qualities for the intended purpose and not only because of how easy it was to break them.
A research group led by the Nagoya University Museum and the Japan Graduate School of Environmental Studies has clarified differences in the physical characteristics of rocks used by early humans. They publish the results in the Journal of Paleolithic Archaeology.
When Homo sapiens moved from Africa to Eurasia, they used stone tools made from rocks, such as obsidian and flint, to cut, slice, and make ranged weapons. Due to the important role they played in their culture, for archaeologists It is important to understand how early humans made stone tools.
Since the geographic expansion of Homo sapiens began in Eurasia in the Middle East, archaeologists Eiki Suga and Seiji Kadowaki of Nagoya University have focused on prehistoric sites belonging to three chronological periods in the Jebel Qalkha area of southern Jordan. . The team analyzed flint nodules in outcrops that were exploited during the Middle and Upper Paleolithic (70,000 to 30,000 years ago).
They believe that Paleolithic humans understood which rocks were suitable for making tools and therefore intentionally sought them out. According to their hypothesis, Paleolithic humans intentionally sought flint that was translucent and smooth, as it could be easily broken from the rock wall and shaped with sharp edges.
The group used a Schmidt hammer and a Rockwell hardness device to test the mechanical properties of the rocks. The Schmidt Hammer measures the elastic behavior of a material after the hammer hits it, which tells researchers its rebound hardness. The Rockwell hardness device presses a diamond indenter onto the rock surface to test its strength.
At first, as Suga and Kadowaki expected, it was found that fine-grained chert required less force to fracture than medium-grained chert. This would have made fine-grained flint more attractive for the production of small stone tools. In fact, many stone tools from the Early Upper Paleolithic (40,000 to 30,000 years ago) contain fine-grained chert.
However, an earlier study by the same team found that during the Late Middle Paleolithic and Early Upper Paleolithic (70,000 to 40,000 years ago), medium-grained flint was more commonly used in stone tools than fine-grained flint. . But if fine-grained flint was so easy to use, why didn’t our ancestors make all their tools with it?
Upon further investigation, the researchers discovered that Much of the fine-grained chert in the area suffered from extensive internal fractures caused by geological activities, which would have made it unsuitable for large stone tools, such as Levallois products and robust blades.
Therefore, it appears that Paleolithic humans They selected medium-grain flint for large tools, even though it was a difficult material to modify into tools, as it was more likely to last longer.. This offers a fascinating insight into the behavior of our ancestors, as they selected flint based on many factors other than how easy it was to fracture and were able to discern the most suitable rock for making stone tools, according to the authors.
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