A “major” archaeological development may help rewrite early human history

An innovative technique used to study Neanderthal hearths – the places where fires were made – has been described by researchers as a “major” development in archeology that could help shed light on the behavior of prehistoric people.

For a study published in a journal Naturean interdisciplinary team of researchers found that a series of six Neanderthal hearths at El Salt, a Paleolithic site in Spain, were created over a period of at least 200 to 240 years, with each probably created decades apart.

The findings are significant because determining the time scale of human activity in the Paleolithic period, also known as the Early Stone Age, has long been one of the most challenging problems of prehistoric archaeology. (This period in human prehistory extends from the earliest use of stone tools more than 3 million years ago to about 12,000 years ago.)

Resolving the time frame of such activity is difficult in large part due to the limitations of dating techniques. For example, radiocarbon techniques cannot date samples that are older than about 50,000 to 60,000 years. Meanwhile, other techniques can cause errors of several thousand years.

“Although it has been suggested that Paleolithic hunter-gatherers were highly mobile, key aspects of their lifestyle, such as the time between camps and the size of traveling groups, remain unclear,” the study authors wrote. “The complexity in creating Paleolithic sites makes it difficult to single out episodes of human occupation and resolve the time between them.”

In the latest study, the research team – led by Ángela Herrejón-Lagunilla from Spain’s University of Burgos – tried to solve this problem by examining the hearths at El Salt, dated to around 52,000 years ago, using an innovative technique.

The technique involved a combination of “archaeostratigraphic” analyzes – which helped the team determine the order in which the hearths were created based on their relative position in the earth’s layers – and an approach known as archaeomagnetic dating.

This technique studies and interprets the signatures of Earth’s past magnetic field recorded in burnt archaeological remains. This approach works on the assumption that the burned materials retain a record of the direction and/or strength of the magnetic field at the time of the last fire.

Combining the two approaches revealed that the Neanderthal hearths at El Salt were made decades or even a century apart—a finding that sheds light on the behavior of these early humans, who went extinct about 40,000 years ago. The results provide an indication of the timing of the furnaces at an unprecedented resolution.

“When we survey archaeological settlement sites, we assume they are the result of multiple human activity events, but until now we didn’t know exactly how much time had passed between those activities. We didn’t know if it was decades, centuries or thousands of years,” Santiago said in a press release Sossa-Ríos, a researcher in prehistory, archeology and ancient history at Spain’s University of Valencia and author of the study.

“From there, within this temporal framework, we can open up new lines of inquiry to study, for example, patterns of mobility, technological change or differences in the use of space,” he continued. “The time is there, the challenge is to combine and extract everything the methods have to offer to reveal it.”

Hearths can provide useful information about Neanderthal life as they are good indicators of occupation at a given site.

The new findings suggest that although Neanderthals were highly mobile, in some cases they could return to previous settlements after long periods, but still within individual lifetimes.

In Paleolithic archaeology, a discipline in which human behavior is typically studied over the long timescales typical of geological processes, the ability to observe change on timescales closer to a human life span is a significant development.

As a result, the techniques used in the study could help shed light on Paleolithic hunter-gatherers. They could even be applied to other archaeological contexts to resolve the timing of human activity.

“This is definitely a big step forward in archeology that will help us better understand human behavior in the past,” the study’s authors said in a press release.

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