New study finds that ancient hominins nearly 800,000 years ago deliberately selected specific basalt sources for different stages of tool production rather than simply using whatever stone was available nearby. By tracing the geochemical “fingerprints” of stone tools to both exposed and now-buried basalt flows, the researchers demonstrated that these hominins possessed detailed environmental knowledge, advanced planning abilities, and long-term technological traditions that were maintained and repeated across generations.
Link to photos: https://drive.google.com/drive/folders/1ZbTRtKVLvCwFPINM3sR-_y0mWvzW9k-q?usp=sharing
A new study published in
Scientific Reports provides new insights into the technological behavior and raw material procurement strategies of early Middle Pleistocene hominins at the Acheulian site of Gesher Benot Ya‘aqov (GBY). The study uses geochemical analyses of basalt artifacts and nearby basalt sources to trace where the raw material used for tool production came from, and to reconstruct how early hominins selected stone within a landscape that has changed dramatically over time. The research was carried out by
Dr. Tzahi Golan and Dr. Yoav Ben Dor of the Geological Survey of Israel, and Prof. Naama Goren-Inbar of the Hebrew University of Jerusalem.
GBY, dated to about 780,000 years ago, preserves repeated occupations of Acheulian hominins along the shores of paleo-Lake Hula. Excavations directed by Prof. Goren-Inbar revealed a rich archaeological record, including stone tools made of flint, limestone, and basalt, as well as evidence for fire use, plant exploitation, animal processing, and fish consumption.
Basalt was a significant raw material at the site, especially for the production of large cutting tools such as handaxes and cleavers. Previous studies showed that these tools were produced through a complex reduction sequence: hominins selected large basalt slabs, shaped them into giant cores, detached large flakes, and then modified these flakes into bifaces. This process required planning, technical skill, and detailed knowledge of the properties of basalt.
The current study focuses on another aspect: where did the GBY hominins obtain the basalt used in this production sequence?
To answer this, the researchers analyzed the chemical composition of basalt artifacts from several archaeological horizons and compared them with geological samples from basalt flows around the site. They also analyzed basalt recovered from the Eshel Ya‘aqov borehole drilled at GBY, which provided access to basalt units now buried below the surface. The analyses included major elements, trace elements, rare earth elements, and multivariate statistical methods, allowing comparison of the geochemical “fingerprints” of artifacts and potential sources.
The results show that many basalt artifacts match sources located very close to the site, in some cases within about one kilometer. Some artifacts also match basalt units that are now buried beneath GBY and are no longer exposed at the surface. By combining geochemical fingerprinting with evidence from deep boreholes beneath the site, the researchers were able to reconstruct parts of an ancient landscape that no longer exist today. This approach allowed them to identify basalt flows that were accessible to hominins 780,000 years ago but were later buried or eroded as the Jordan Valley landscape changed through tectonic activity.
This is especially important because GBY lies in a tectonically active region along the Dead Sea Transform. Faulting, subsidence, erosion, and sediment burial have reshaped the local landscape over time. Basalt flows once accessible to hominins may later have been buried, eroded, or removed from the visible surface.
The geochemical results also reveal differences between tool types. Giant cores are closely linked to nearby and buried local basalt sources, whereas some cleavers appear to have been procured from sources not represented among the sampled exposures. This suggests that hominins did not simply collect any available basalt, but selected particular sources according to technological needs such as slab size, shape, internal structure, or suitability for cleaver production.
The study also highlights differences between tool types. Some cleavers appear to have been made from basalt sources different from those used for most handaxes and giant cores. This is particularly significant because previous research at GBY showed that cleaver production required especially advanced planning and technical expertise. The findings suggest that hominins deliberately searched for basalt with specific qualities suited to particular tools.
The same raw-material selection strategies appear repeatedly across multiple archaeological layers, indicating a long-lasting technological tradition that persisted over tens of thousands of years. The results suggest that Acheulian hominins at GBY possessed detailed environmental knowledge that was maintained and transmitted across generations.
By combining archaeology, geology, and geochemistry, the study shows that raw material selection at GBY was structured and repeated over time, highlighting the ability of Acheulian hominins to plan, select, and exploit geological resources within a changing landscape nearly 800,000 years ago.
The findings show that these Acheulian hominins knew how to identify “the right rock for the right tool at the right time,” demonstrating sophisticated planning and deep familiarity with their environment.