Ancient wildfires and erosion in the southern Levant may have helped Neolithic communities discover that fire could transform clay into pottery, a recent study found.

The study, published in early September in Geomorphology, analyzes evidence taken from ancient sediment, caves, charcoal deposits, and archaeological sites across the region in order to reconstruct how the Levant was shaped during two periods of major environmental instability.

Evidence comes from what lead researcher Prof. Amos Frumkin of the Hebrew University of Jerusalem’s Institute of Earth Sciences calls the “natural kiln hypothesis.”

According to Frumkin’s hypothesis, Neolithic communities at the time may have learned that clay could be permanently hardened by fire after witnessing such phenomena occurring naturally after intense fires.

The study compared two periods separated by more than 100,000 years.

The first period the study analyzed wass the last interglacial period, known as MIS 5e, which took place roughly 129,000 to 116,000 years ago. The second was the early Holocene, between approximately 11,000 and 7,000 years ago, when farming communities became increasingly more established across the region.

Evidence from both periods points to a series of extensive wildfires followed by severe erosion. 

Tiny charcoal particles preserved in ancient lake sediments record peaks in burning, the study noted, while chemical signatures preserved in cave formations indicate substantial losses of vegetation and soil. During the early Holocene, the most intense episode appears to have occurred around 9,500-8200 years ago.

Although Neolithic and earlier people deliberately used fire on a limited scale, Frumkin argued that the geographical extent and timing of the fires point to climatic causes for increasing use of fire.

He explained that once fires burned away the existing vegetation, the exposed soil then became vulnerable to rain and runoff. Clay-rich soil moved from the hillsides and was deposited in natural depressions, such as the Jordan and Dead Sea valleys, in large quantities.

Such change created fertile regions where farming communities could settle and flourish.

Could nature have demonstrated how to make pottery?

Pottery appeared in the region during roughly the same broad period in which fires, erosion and clay deposition reached their peak. 

Frumkin claimed that people living in the valleys may have encountered patches of clay that had been exposed to intense natural fires and noticed that the heat had transformed the softer material into something hard and durable.

That observation could have provided the basic idea behind intentionally firing clay. 

The hypothesis is supported by earlier petrographic research showing that Yarmukian pottery from the Jordan Valley was manufactured from local redeposited terra rossa clay, the same material that would have accumulated around settlements following the erosion of nearby hills.

“A wildfire is normally seen only as a catastrophe, but environmental disruption can also expose people to new materials and new possibilities,” said Frumkin. “Neolithic communities in the Jordan Valley may have watched fire transform the clay beneath and around their settlements and realized that this process could be reproduced deliberately.”

“If so, one of humanity’s most important technologies may have emerged partly from people learning to imitate what they had already seen nature do.”

A 120,000-year-old ‘natural experiment’

During the last interglacial, which predated the last glacial period, the southern Levant experienced an even more extreme combination of fires, vegetation loss, erosion and clay deposition. Despite this, the study noted, pottery did not appear.

Frumkin described the last interglacial as a natural “control experiment.”

While the environment produced and met many of the same later conditions that may have led to the creation of pottery, the people living in the region did not have the same cognitive abilities, knowledge, and social conditions that later Neolithic communities had.

Frumkin stressed that the natural kiln hypothesis is “speculative and testable,” rather than a proven account of pottery’s invention. 

The available evidence established that major fires, clay deposition and the emergence of pottery occurred within the same broad period of time, but current dating cannot yet identify the exact sequence of events.