Ice age humans built sophisticated fireplaces
Evidence from a prehistoric site at the shore of the Dnister river in modern-day Ukraine shows that people living during the most recent ice age built different types of hearths. Wood served as their primary source of fuel, but they may have used fat and bones as well. The findings were published April 1 in the journal Geoarchaeology.
Archaeologists believe that Homo sapiens in Europe during the Upper Paleolithic period (between 45,000 and 10,000 years ago) used fire in several different ways.
'Fire was not just about keeping warm; it was also essential for cooking, making tools and for social gatherings,' Philip R. Nigst, a study co-author and archaeologist at the University of Vienna in Austria, said in a statement.
[ Related: Ancient rocks tie Roman Empire's collapse to a mini ice age. ]
Fire was likely a key part of survival for ice age hunter-gatherers in what is now Europe. Yet a lack of evidence from the coldest part of the ice age has prevented scientists from saying how.
'We know that fire was widespread before and after this period, but there is little evidence from the height of the Ice Age,' William Murphree, a study co-author and geoarchaeologist at the University of Algarve in Portugal, said in a statement.
In the new study, the team analyzed three hearths unearthed at a prehistoric site in Ukraine. Through microstratigraphic analysis, micromorphology and colorimetric analysis, the scientists identified three simple, flat, wood-fired hearths. Interestingly, the analysis shows that one of these fires reached over 1,112 degrees Fahrenheit (600 degrees Celsius). According to the team, this proves that whoever made these fires had a more sophisticated mastery of pyrotechnics, despite the harsh environments they lived in.
Humans used wood as their main fuel source during the peak of the ice age. The charcoal analysis indicates that it was specifically spruce wood. However, animal bones or fat may have also been used to keep fires burning.
'Some of the animal bones found at the site were burnt in a fire with a temperature of over 650 degrees Celsius [1,202 degrees Fahrenheit]. We are currently investigating whether they were used as fuel or just accidentally burned,' study co-author and University of Vienna zooarcheologist Marjolein D. Bosch said in a statement.
[ Related: Ice Age hunter-gatherers may have had cheek piercings, even as children. ]
All three fireplaces are open and flat. The team's analysis suggests that their use of fire was sophisticated, because the fireplaces were likely to have been constructed and used differently depending on the season. One fireplace is larger and thicker, suggesting that it could reach higher temperatures.
'People perfectly controlled the fire and knew how to use it in different ways, depending on the purpose of the fire. But our results also show that these hunter-gatherers used the same place at different times of the year during their annual migrations,' said Nigst.
Even with these new findings, numerous questions remain, particularly about why there is such scant evidence of fireplaces dating back to the last ice age.
'Was most of the evidence destroyed by the ice-age-typical, alternating freezing and thawing of the soil?' asks Murphree.
'Or did people not find enough fuel during the Last Glacial Maximum? Did they not use fire, but instead relied on other technological solutions?' adds Nigst.
The team hopes that understanding more about the role fire plays in human evolution will reveal how it helped our species become dominant.
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