Radioactive dating sparks controversy
But the new study suggests that the sediment might be over 80,000 years old, possibly formed during an ice age.
"The carbon-14-based mega-lake hypothesis was even incorporated into modelling work to interpret regional climate dynamics,” the paper reported.
The analysis, conducted by James Paces of the United States Geological Survey, pointed to a “burial date of 130.7 ± 9.4 thousand years ago.” into the Americas.” Who these people were, or when or where they came from, the authors do not venture to guess. 4: The Indisputable Facts in the Artifacts The findings and conclusion have led to strong protests from the archeological community.
The primary rebuttal is that the bones could have been smashed by other causes. Holliday, an archaeologist at the University of Arizona, argues that the authors “don’t demonstrate that they could only be broken by humans.” Southern Methodist University archaeologist David Meltzer similarly says that “you cannot take broken bones and nondescript stones to make the case, not without demonstrating that nature could not have broken those bones and modified those stones.” Some archeologists, like Gary Haynes of the University of Nevada Reno argued that it could have been the bulldozers, which “weigh seven to fifteen tons or more, and their weight on the sediments would have crushed bones and rocks against each other.” However, if the evidence in the report is correct, that the mastodon was freshly killed when the bones were smashed, it rules out the bulldozers and begs the question, if humans didn’t do it, what did? Deméré argued that, “It’s kind of hard to envision a carnivore strong enough to break a mastodon leg bone.” Other archeologists, such as Michael Waters of Texas A&M’s Center for the Study of the First Americans, feel that the stones described in the paper do not unequivocally look like tools. Andrew Hemmings, from Florida Atlantic University, says it is not clear what the humans, if they were humans, were doing, given that a mastodon tooth was shattered along with bones.
By comparing results from the two methods, they found that carbon dating became unreliable beyond a range of 30,000 years.
The great lakes are widely believed to have appeared in China due to the massive melting of ice sheets during an exceptionally warm period some 40,000 years ago, and sediment from Xingkai Lake served as key evidence.
“Humans and Neanderthals were living contemporaneously for quite some period of time in different parts of Europe,” says Tom Higham, an archaeologist at the University of Oxford, UK, who led the study.
You’ll still be able to search, browse and read our articles, but you won’t be able to register, edit your account, purchase content, or activate tokens or eprints during that period.
has set the archeological abuzz, claiming that 130-000 year-old mastodon bones unearthed near San Diego were smashed and broken by ancient humans to extract their marrow or to make bone tools.
Prior to that, they had to depend on more rudimentary and imprecise methods, such as counting the number of rings on a cross-section of tree trunk.
This all changed in the 1940s when US chemist Willard Libby discovered that carbon-14, a radioactive isotope, could be used to date organic compounds.