Volcanic eruption witnessed by prehistoric humans

A volcanic eruption believed to be eye-witnessed by humans in prehistoric times happened 245,000 years later than originally expected, according to new research involving Curtin University researchers.

Çakallar volcano, as seen from the southeast. The overlay is a 3D model of one of the Bronze Age prints,
known as the "Kula footprints" because they are in Kula Volcanic Geopark
[Credit: Erdal Gumus/Curtin University]

The research, published in Quaternary Science Reviews, aimed to determine the age of prehistoric footprints found in the ash layer produced by the Çakallar volcano eruption, which took place in the town of Kula in western Turkey thousands of years ago.

Along with the footprints, a rock painting was discovered in close proximity to the eruption site in the Kula UNESCO Geopark, in Manisa Province, Turkey. The painting, which illustrates the eruption of the volcano, highlights how humans from thousands of years ago were able to illustrate natural phenomena in their own way.

Lead Australian author Dr. Martin Danišík, from the John de Laeter Centre based at Curtin University, said previous studies suggested the footprints belonged to Homo neanderthalensis from the Pleistocene age, but the new findings indicated they may be younger than previously thought.

From left to right: Ancient humans painted this illustration on a rock shelter near a volcano; a colour-enhanced version
of the rock art, which enhances the cone-shaped feature, the lower elongated line, the three-fingered handprints
and other details; a reconstructed version of the painting [Credit: Ulusoy et al., 2019]

"The footprints, widely known as 'Kula footprints,' were discovered in the 1960s when construction workers, who were moving volcanic rock away from one of the volcanoes in the area, found them well-preserved in fine-grained volcanic ash," Dr. Danišík said.

"Our team was able to determine the age of the volcanic ash that preserved the footprints by using two different techniques. A radiogenic helium dating method was used to measure the eruption age of tiny zircon crystals, and the cosmogenic chlorine exposure dating method was used to measure the time that the volcanic rocks have been residing near the Earth's surface.

"The two independent dating approaches showed internally consistent results and collectively suggest that the volcanic eruption was witnessed by Homo sapiens during the prehistoric Bronze Age, 4,700 years ago and 245,000 years later than originally reported."

A researcher takes a photo of a footprint for 3D modeling. It's unclear if this print
belongs to a human or animal [Credit: Erdal Gumus]

The research also suggests that after the initial eruption, humans and their canine companions slowly approached the volcano, leaving distinctive footprints in the wet ash blanket on the surface. Volcanic activity continued, causing dark-colored volcanic rock to bury the ash and therefore preserve the footprints.

Dr. Danišík explained that the humans witnessed the final stages of the volcanic eruption from a safe distance, making it highly likely the Homo sapiens were also responsible for the rock paintings discovered close to the site.

"The rock painting is a fascinating connection to the footprints, as it showcases how humans from 4,700 years ago were able to paint natural processes, such as a volcanic eruption, in their own artistic way with limited tools and materials," Dr. Danišík said.

Source: Curtin University [May 30, 2019]