Archaeologists investigating the Kalahari Desert have discovered nearly 100 stone hand axes and evidence of their manufacture, providing new clues about how early hominins occupied the changing landscapes of southern Africa.
The artefacts were discovered in the Okwa Valley, an arid and difficult-to-access region extending from the border between Botswana and Namibia.
Researchers from the University of Wrocław have identified several locations containing stone tools associated with the Acheulean technological tradition, which first appeared in Africa around 1.7 million years ago and persisted in some regions until approximately 200,000 years ago.
However, the precise age of the newly discovered Kalahari artefacts has yet to be established.
During the latest field season, archaeologists recovered approximately 40 hand axes from a single site. They were accompanied by debris produced during tool manufacture and the reduction of larger blocks of stone.
Across their investigations in the Kalahari, the researchers have now collected nearly 100 hand axes.
The presence of manufacturing debris is particularly useful because it can help archaeologists reconstruct how the tools were produced rather than simply documenting finished objects.
“It is currently believed that the Acheulean tradition emerged around 1.7 million years ago and persisted until approximately 200,000 years ago,” said Professor Mirosław Masojć, director of the Institute of Archaeology at the University of Wrocław.
“Its most characteristic element is large stone tools, called hand axes.”
Acheulean hand axes are among the most recognisable artefacts of the Lower Palaeolithic. Typically shaped by removing flakes from both sides of a stone blank, they occur across large parts of Africa and later appear in parts of Asia and Europe.
The newly discovered examples will now be compared with Acheulean hand axes from areas north of the Kalahari and from South Africa.
The artefacts are undergoing detailed analysis at the AGH University of Science and Technology in Kraków.
The Okwa Valley presents considerable challenges for archaeological research. Although popularly associated with open desert, much of this part of the Kalahari is covered by dense bush, making systematic surveys difficult.
“The Okwa Valley is an exceptionally difficult area to research,” Masojć said. “Dense bush limits access to many sites and hinders systematic archaeological exploration.”
As a result, the region remains comparatively poorly understood despite its potential importance for reconstructing early human activity in southern Africa.
During the Pleistocene, the landscape was very different from the arid environment seen today.
Researchers have identified evidence that an extensive system of rivers and lakes once existed in the Okwa Valley. These ancient water sources would have transformed the landscape and potentially provided attractive locations for hominin activity.
The archaeological team found hand axes along the shores of one of these former bodies of water.
An unexpected aid to the investigation has come from local excavations for calcrete, a calcium carbonate-cemented sediment commonly used for road construction in Botswana.
These excavations expose deeper Kalahari sediments that would otherwise remain hidden beneath the landscape, allowing archaeologists and geologists to examine the valley’s geological history.
Within these exposures, researchers identified traces of Pleistocene rivers and a former lake, helping place the stone artefacts within their ancient environmental setting.
The next stage of research will combine technological analysis of the hand axes with studies of the surrounding sediments, chronology and past environmental conditions.
Researchers hope this will establish when hominins were using the Okwa Valley and reveal how they moved through and exploited the landscape as southern Africa’s environment changed over hundreds of thousands of years.
The project is being conducted by researchers from the University of Wrocław in cooperation with the University of Botswana, the Korea Institute of Geoscience and Mineral Resources and the Polish Geological Institute – National Research Institute.
For now, the discoveries demonstrate that the poorly explored interior of the Kalahari preserves substantial evidence of Acheulean activity, potentially opening a new window onto some of the earliest chapters of human occupation in southern Africa.
Sources : PAP
