Nav: Home

Cornell research illuminates inaccuracies in radiocarbon dating

June 05, 2018

ITHACA, N.Y. - Radiocarbon dating is a key tool archaeologists use to determine the age of plants and objects made with organic material. But new research shows that commonly accepted radiocarbon dating standards can miss the mark -- calling into question historical timelines.

Archaeologist Sturt Manning and colleagues have revealed variations in the radiocarbon cycle at certain periods of time, affecting frequently cited standards used in archaeological and historical research relevant to the southern Levant region, which includes Israel, southern Jordan and Egypt. These variations, or offsets, of up to 20 years in the calibration of precise radiocarbon dating could be related to climatic conditions.

Manning, professor of archaeology at Cornell University and director of the Cornell Tree-Ring Laboratory, is the lead author of "Fluctuating Radiocarbon Offsets Observed in the Southern Levant and Implications for Archaeological Chronology Debates," published in the Proceedings of the National Academy of Sciences.

Pre-modern radiocarbon chronologies rely on standardized Northern and Southern Hemisphere calibration curves to obtain calendar dates from organic material. These standard calibration curves assume that at any given time radiocarbon levels are similar and stable everywhere across each hemisphere.

The Cornell-led team questioned those assumptions.

"We went looking to test the assumption behind the whole field of radiocarbon dating," Manning said. "We know from atmospheric measurements over the last 50 years that radiocarbon levels vary through the year, and we also know that plants typically grow at different times in different parts of the Northern Hemisphere. So we wondered whether the radiocarbon levels relevant to dating organic material might also vary for different areas and whether this might affect archaeological dating."

The authors measured a series of carbon-14 ages in southern Jordan tree rings, with established calendar dates between 1610 and 1940 A.D. They found that contemporary plant material growing in the southern Levant shows an average offset in radiocarbon age of about 19 years compared the current Northern Hemisphere standard calibration curve.

Manning noted that "scholars working on the early Iron Age and Biblical chronology in Jordan and Israel are doing sophisticated projects with radiocarbon age analysis, which argue for very precise findings. This then becomes the timeline of history. But our work indicates that it's arguable their fundamental basis is faulty - they are using a calibration curve that is not accurate for this region."

Applying their results to previously published chronologies, the researchers show how even the relatively small offsets they observe can shift calendar dates by enough to alter ongoing archaeological, historical and paleoclimate debates.

"There has been much debate for several decades among scholars arguing for different chronologies sometimes only decades to a century apart - each with major historical implications. And yet these studies ... may all be inaccurate since they are using the wrong radiocarbon information," Manning said.

"Our work," he added, "should prompt a round of revisions and rethinking for the timeline of the archaeology and early history of the southern Levant through the early Biblical period."
-end-
Cornell University has television, ISDN and dedicated Skype/Google+ Hangout studios available for media interviews.

Cornell University

Related Archaeology Articles:

Study could provide first clues about the social lives of extinct human relatives
A new study from The Australian National University (ANU) of the bony head-crests of male gorillas could provide some of the first clues about the social structures of our extinct human relatives, including how they chose their sexual partners.
Archaeologists use drones to trial virtual reality
Archaeologists at The Australian National University and Monash University are conducting a trial of new technology to build a 3-D virtual-reality map of one of Asia's most mysterious sites -- the Plain of Jars in Laos.
Archaeology under the canopy
UCSB's Anabel Ford has devoted her career to conservation and research at the ancient Maya city.
Ancient rice may hold key to solving the puzzle of the settlement of Madagascar
Archaeologists studying the distribution of ancient rice believe they may be close to solving one of the enduring mysteries of the ancient world -- how people of South East Asian origin ended up living on the African island of Madagascar, 6,000 km away.
High altitude archaeology: Prehistoric paintings revealed
Archaeologists at the University of York have undertaken pioneering scans of the highest prehistoric paintings of animals in Europe.
Ancient Irish musical history found in modern India
An archaeologist studying musical horns from iron-age Ireland has found musical traditions, thought to be long dead, are alive and well in south India.
New archaeological method finds children were skilled ceramists during the Bronze Age
Artisanal interpretation of ceramics from the Bronze Age shows that a 9-year-old child could be a highly skilled artisan.
Underwater archaeology looks at atomic relic of the Cold War
The April issue of Springer's Journal of Maritime Archaeology focuses on a single shipwreck as the lens through which maritime archaeology assesses the advent of the Atomic Age and the Cold War.
New discoveries into how an ancient civilization conserved water
High-resolution, aerial imagery bears significance for researchers on the ground investigating how remote, ancient Maya civilizations used and conserved water.
A new countryside legacy from Roman Britain
New research from the University of Exeter has found that the Roman influence on our landscape extends beyond the legacy of our urban infrastructure to also shape the countryside and our rural surroundings.

Related Archaeology Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".