The controversial ancient human footprints preserved at White Sands National Park in New Mexico have sparked intense debate for years. A new study suggests that these footprints may be approximately 23,000 years old, though this dating remains disputed.
If the 23,000-year estimate holds true, it indicates that humans were present in North America during the peak of the last major glacial period—the last ice age—much earlier than previously believed by archaeologists.
In this latest research, scientists employed radiocarbon dating on organic deposits extracted from core samples at the site. This analysis yielded dates spanning the Paleolake and river systems that once thrived in the area, conducted in an independent laboratory not associated with prior studies.
“Our findings corroborate the original data suggesting the site dates back 23,000 years,” stated Vance Holiday, professor emeritus of anthropology and geoscience at the University of Arizona, in an interview with Live Science. “We now have insights into the environment that existed when these people were present.”
The saga dates, based on about 60 footprints identified back in 2021, referenced a study that proposed the footprints dated to between 21,000 and 23,000 years ago. However, a 2022 rebuttal raised concerns over the dating methods, which involved using seeds from aquatic plants for radiocarbon dating. Since these plants absorb carbon from water, which can often be much older than atmospheric carbon, this can lead to skewed results indicating an age that is younger than the actual one.
In 2023, researchers applied optically stimulated luminescence (OSL) dating, revealing when quartz or feldspar grains last saw sunlight, and conducted radiocarbon dating of ancient conifer pollen from the layer containing the footprints. This method provided an alternative to the carbon dating affected by aquatic plants.
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Currently, scientists again indicate that the footprints date to between 21,000 and 23,000 years. Some researchers find the evidence “very persuasive,” while others, including the authors of the 2022 rebuttal, remain skeptical, suggesting that the sample may not have come from the appropriate context.
The latest study provides further evidence that these footprints date back to the height of the last glaciation, suggesting that hunter-gatherers might have inhabited a vast wetland filled with ice age fauna. Research indicates that they possibly arrived in the U.S. via the Bering Land Bridge, which linked Siberia and Alaska during periods of lower sea levels.
For years, Clovis was thought to represent the earliest known inhabitants of North America, dating to around 13,000 years ago. Nonetheless, the discovery of these footprints, along with others and more, gradually suggests that Indigenous peoples may have arrived in America much earlier than previously thought.
A New Perspective on White Sands
Holliday has been studying White Sands since 2012 and contributed data to the original 2021 study. In the present study, he and his team analyzed mud cores with radiocarbon from the site, revealing that the trackway dates back to between 20,700 and 22,400 years ago, aligning closely with the original findings.
From the footprint layer, which supports dates ranging from 21,000 to 23,000 years, they gathered 55 radiocarbon samples from mud, seeds, and pollen, as noted by Holiday.
The footprints of ancient humans “are rarely preserved,” he stated. Yet scientists now have “dates from three different materials that all align” with the timeline of these tracks.
“Getting this level of consistency in dating is quite challenging to dismiss,” he remarked in a statement. “It would be a remarkable coincidence for three different dating methods to all yield incorrect results.”
Nonetheless, more work is needed to definitively date the footprints at White Sands, suggests Michael Waters, director of the First Americans Research Center at Texas A&M University.
“Even with this new data, I remain cautious regarding the radiocarbon ages associated with the White Sands footprint,” Waters conveyed in an email to Live Science. He reiterated the issues concerning Rappier and noted that the radiocarbon dates could be “too old” as the plants may have absorbed carbon from the water. He also cautioned that the same underwater carbon concerns could apply to sediments dated in the new study.
“The new ages for the organic deposits presented in this research are intriguing, but the source of the carbon remains uncertain,” Waters remarked.
Additionally, Holliday and his team acknowledged that their research has not resolved another pressing question: where are the artifacts and settlements of these ice age peoples associated with the footprints?
This question remains unanswered, as Holiday noted. However, it seems probable that hunter-gatherers may not have left behind significant artifacts during their brief sojourns in the marshlands.
“These people were alive with their artifacts and were quite distant from areas where they could have accessed exchange materials,” Holiday stated. “It doesn’t make sense to think they would leave artifacts behind randomly; it just isn’t logical to have a field filled with shards.”
Source: www.livescience.com