El Sidron cave
April 3, 2013

New Dating Procedures Give More Accurate Age Of El Sidron Cave Neanderthals

April Flowers for redOrbit.com - Your Universe Online

A new study, led by the University of Oviedo, Spain, has been able to accurately determine the age of Neanderthal remains found in the El Sidron cave of Asturias, Spain. Previous studies have provided inexact measurements for the remains. The new study found that a pre-treatment to reduce modern carbon contamination has lowered the margin of error from 40,000 to 3,200 years.

One of the westernmost Neanderthal sites on the Iberian Peninsula, the El Sidron cave in Asturias contains a large amount of remains such as these, along with the flint tools they used. The study, published in the journal Archaeometry, used new analytical procedures to provide a more accurate dating for the Neanderthal populations in Asturias.

In the debate about when the transition from Neanderthal to Homo sapiens happened in Europe, the age of the El Sidron remains could prove to be an important piece of information. "Some previous datings that stated the remains were only 10,000 years old are inconsistent and cannot be considered credible. They would be highly disputed in the discussion about when Homo neanderthalensis became extinct," explained Marco De La Rasilla, coordinator of the research team.

De La Rasilla and his colleagues compared previous results from the French Climate and Environmental Sciences Laboratory (LSCE), with new data obtained by the Oxford Radiocarbon Accelerator Unit (ORAU) in order to adjust the age of these Neanderthal remains. The data obtained from both laboratories enabled the team to confirm that the remains in the Asturian cave lived some 49,000 years ago.

"The previous measurement of 10,000 years for this episode was due to a contamination issue," De La Rasilla explained. The most widely used dating method in archaeology is carbon-14 dating, which measures the age of the carbon found in an object. If modern carbon or other substances contaminate the sample, the object may appear younger than it actually is.

Before the new carbon-14 dating was performed in Oxford's ORAU laboratory, the samples were processed through a highly sophisticated ultrafiltration treatment to reduce as much contamination as possible. This revealed the remains are between 45,200 and 51,600 years old.

The French laboratory performed a similar test, pre-treating with ninhydrin to remove contaminants. The weighted average between the two data sets places the Neanderthal inhabitants of El Sidron around 49,000 years ago.

"The fact that two separate laboratories using different treatments came up with similar figures makes this date even more reliable" De La Rasilla concluded.