Monte Verde Age Dispute: New Dating Challenges Early Americas Settlement Timeline

A long-held understanding of the timeline for the first human settlements in South America is facing scrutiny. Recent research challenges the established date of approximately 14,500 years for the Monte Verde archaeological site in Chile, one of the oldest known sites in the Americas, suggesting it may be significantly younger. The findings, published Thursday in the journal Science, have sparked debate, with some archaeologists dismissing the re-evaluation as flawed.

Monte Verde: A Pivotal Site in the Americas’ Peopling

Located in the mountains of southern Chile, Monte Verde was discovered in 1976 and quickly became central to the debate surrounding the peopling of the Americas. The site has yielded a remarkable collection of artifacts, including stone tools, preserved wood, bones and skin from extinct animals, a human footprint, edible plant remains, hearths, and even evidence of rope-making. Radiocarbon dating initially placed the occupation level, known as Monte Verde II (MV-II), at around 14,500 years ago. This date was groundbreaking because it suggested that humans arrived in South America before the Clovis people, who were previously thought to be the first inhabitants of the continent, arriving around 13,000 years ago via an ice-free corridor in North America.

The Monte Verde findings challenged the “Clovis First” model, prompting a re-evaluation of migration routes and timelines. Since then, other pre-Clovis sites have been identified across the Americas, including Paisley Caves in Oregon, White Sands in New Mexico, and sites in Texas and Florida. However, Monte Verde II remains unique as the only securely dated Late Pleistocene archaeological site in South America.

Re-Evaluating the Evidence: A Younger Monte Verde?

The new study, led by Todd Surovell of the University of Wyoming and Claudio Latorre of the Pontifical Catholic University of Chile, re-examined the age and formation of the MV-II site. The researchers concluded that Monte Verde was likely occupied during the Middle Holocene, between 4,200 and 8,200 years ago – a considerably more recent timeframe. Their analysis centers on the geological context of the site, specifically the presence of a volcanic ash layer known as the Lepué Tephra.

Surovell and Latorre argue that the site is situated on top of this tephra layer, deposited approximately 11,000 years ago from a volcanic eruption. They suggest that erosion cut a channel through the area, and that any older materials found at the site were redeposited there, creating the illusion of a greater age. They re-dated charcoal and wood samples from the area, obtaining dates ranging from 13,400 to 16,500 years ago, consistent with previous studies, but interpret these dates as reflecting the age of the redeposited materials, not the original occupation of the site.

Strong Disagreement and Geological Concerns

The study’s conclusions have been met with strong opposition from other archaeologists, most notably Tom Dillehay, the archaeologist at Vanderbilt University who originally excavated Monte Verde. Dillehay asserts that there is no evidence of the Lepué Tephra layer underneath the MV-II site, and that the researchers are applying findings from other areas to the site incorrectly. He and his team are preparing a detailed response to address what they consider to be methodological and contextual errors in the new study.

Michael Waters, a geoarchaeologist at Texas A&M University, likewise expressed concerns about the study’s geological analysis, describing it as “egregiously poor geological work.” He points out inconsistencies in the authors’ interpretation of the site’s formation, arguing that their claim of a terrace formed by both erosion and deposition is geologically impossible. Waters emphasizes the need for more comprehensive geological analysis, including micromorphology, wood identification, and analysis of ancient soil layers (paleosols) and volcanic ash (cryptotephras).

What Does This Mean for Understanding the First Americans?

The debate surrounding Monte Verde highlights the complexities of reconstructing the history of the first Americans. Even if the new dating is accurate, many archaeologists believe it won’t fundamentally alter the broader narrative. Kenneth Feder, an archaeologist and author, notes that regardless of Monte Verde’s age, the likelihood remains that the first people to reach the Americas traveled along the coast, before the ice-free corridor opened up.

Surovell, however, suggests that a re-evaluation of Monte Verde could have broader implications, potentially challenging the accepted timelines for other pre-Clovis sites, such as White Sands in New Mexico. He argues for the need for more rigorous dating and geological analysis at these sites to ensure accurate interpretations.

The Importance of Context and Geological Analysis

This controversy underscores the critical role of geological context in archaeological dating. Radiocarbon dating provides a measure of the age of organic materials, but the accuracy of that date depends on understanding how those materials were deposited and whether they have been disturbed or moved over time. The presence of the Lepué Tephra layer, if confirmed, provides a crucial marker for understanding the site’s geological history and the potential for redeposition of older materials.

Looking Ahead: Further Research and Ongoing Debate

The debate over Monte Verde is likely to continue as researchers gather more evidence and refine their interpretations. Further geological analysis, including the techniques suggested by Waters, will be crucial for resolving the questions surrounding the site’s age and formation. The ongoing research will contribute to a more nuanced understanding of the peopling of the Americas, a story that continues to unfold with each new discovery. The scientific team behind the Monte Verde Project is preparing a detailed response to the new study, promising a systematic examination of the methodological and empirical concerns raised.

the story of Monte Verde serves as a reminder of the dynamic nature of archaeological research and the importance of critical evaluation and ongoing investigation.