Dating mummies is an essential analysis that allows archaeologists to accurately reconstruct the history of ancient civilizations. Among the various methods of archaeological dating, carbon-14 analysis has become an indispensable tool for researchers. However, its application to mummies often presents methodological challenges such as sample selection, contamination risks, chronological limitations, and the corrections needed to mitigate these risks.

In this article, we explore in detail the radiocarbon dating process: its specific applications to Egyptian and Andean mummies, as well as the scientific methods available to us that help optimize the accuracy of carbon-14 dating of mummies.

Specific features of carbon-14 dating of mummies

Carbon-14 dating is an essential analytical method that helps archaeologists establish the chronology of mummies. However, archaeologists must ensure reliable results, and they face several technical and methodological challenges. Among these, sample selection, contamination, and isotopic biases are challenges that must be overcome.

Type of samples to be analyzed

To date a mummy using carbon-14, researchers must collect organic material from it. The main samples available to them are:

• Mummified biological tissues: skin, hair, tendons or bones.
• Mummy bandages: often made of linen, an organic material that can be directly used for analysis.
• Biological residues: dried fluids, pigments applied to the body, or embalming resins. However, their use can pose a problem for dating, as we will see later.

Mummy hair is a particularly interesting material for carbon-14 dating because of its resistance to degradation. A study has shown that a specific protocol allows for the extraction of keratin from the hair cortex and requires only about 20 milligrams of sample, which minimizes the impact on the mummy’s integrity while providing accurate dates. This technique is particularly well-suited for mummies preserved in museums. 

Why are mummies harder to date?

Although there is a wide variety of samples that can be analyzed from a mummy, several factors complicate carbon-14 dating:

• Modern contamination: Exposure to recent preservatives (varnishes, resins, bitumen) can skew the ¹⁴C/¹²C ratio measurement.
• Conservation environment: the development of micro-organisms could artificially rejuvenate dating, if they are not strictly eliminated.
• Aging of organic material: poor preservation could prevent the collection of enough material for accurate dating.

A study conducted on the golden mummy of Dunkirk has shown that sample selection and chemical pretreatment were crucial to ensuring the reliability of the results. The process of selectively extracting keratin from the hair thus made it possible to eliminate exogenous materials and obtain a reliable date.

How is a mummy dated?

Reliable carbon-14 dating of mummies relies on a rigorous protocol of sampling, preparation and laboratory analysis. Each step is designed to eliminate possible biases and guarantee optimum accuracy despite the challenges inherent in ancient materials. 

Sample preparation and extraction

Carbon-14 dating requires meticulous sample preparation. This involves several crucial steps:

• Mechanical and chemical cleaning : this refers to chemical pre-treatment techniques (ABA method: acid-base-acid) to remove modern contaminants.
• Selection of the most reliable fractions: mummified hair is preferred as it offers better resistance to environmental alterations.
• Isotope filtering: analysis of carbon isotope ratios to detect any anomalies.

Laboratory Analysis

C14 analysis relies on precise laboratory steps to guarantee reliable and scientifically robust results:

• Measuring the ¹⁴C/¹²C ratio: gas pedal mass spectrometry (AMS) can analyze very small samples.
• Isotopic bias control: are adjustments to account for natural isotopic fractionation.
• Calibration of results: based on IntCal 20 or SH Cal20 calibration curves, essential for correcting historical carbon-14 fluctuations.

Examples of Mummy Dating

Egyptian mummies: dating burial bandages

The linen bandages that wrap Egyptian mummies provide excellent reliability for carbon-14 dating. A study conducted on mummies from the New Kingdom confirmed that they date to the 18th Dynasty using accelerator mass spectrometry (AMS). This technique allows for the analysis of very small samples, thereby minimizing the impact on the mummy’s integrity.

The study of funerary textiles, conducted notably at El Deir in Egypt, has opened up new avenues for dating mummies. Researchers have thus been able to identify different types of textiles, including new linen bandages and fabrics used in everyday life. This approach, which uses reference material, not only allows for the dating of mummies but also provides information on funeral practices and the social status of the deceased.

A remarkable example is the mummy of Nesi-Khons, which has been dated to between the 4th and 1st centuries BCE. The bandages of this mummy contained not only an Etruscan text on linen but also a papyrus from the Egyptian Book of the Dead, thus offering a unique opportunity to cross-reference textual data with carbon-14 dating.

Andean Mummies: Environmental Challenges

A recent study of mummies discovered in the Argentine Andes employed an innovative approach: researchers conducted a counter-dating analysis by dating the lice nits found on the mummies’ hair. This method made it possible to estimate the age of these mummies at between 1,300 and 2,300 years, while also providing valuable genetic information about the mummified individuals.

Complex Cases: Contaminated Mummies

Some mummies were treated with modern substances during the 19th century. To counteract this contamination and ensure reliable dating, scientists must thoroughly clean the samples before analysis in order to obtain usable results. The case of the mummy of Ramses II perfectly illustrates this contamination issue.

Natural mummies: challenges and opportunities

Natural mummies—bodies formed under specific environmental conditions that ensure their preservation—present unique challenges for dating. 

For example, remains preserved in permafrost or peat may have absorbed ancient carbon, which skews the results of carbon-14 dating. In these specific cases, scientists combine several methods in addition to carbon-14 dating—such as pollen or wood analysis—to obtain reliable dates.

Carbon-14 is currently the gold standard for dating mummies. Thanks to rigorous sample preparation protocols and accelerator mass spectrometry (AMS), it is possible to obtain precise dates for various organic materials while minimizing the risk of contamination. When combined with data from excavations, these results provide a better understanding of burial practices, preservation conditions, and the history of ancient civilizations. The CIRAM laboratory employs these methods to support research projects and archaeological studies involving ancient human remains.

Patrick Rossetti

Patrick is the director of the Archaeology Department at CIRAM laboratory. He coordinates projects involving dating, isotopic analysis, and the characterization of archaeological materials, in collaboration with research institutions, museums, and archaeologists in France and abroad (ORCID: 0000-0001-8770-6732).

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