Ötzi the Iceman
Concept Question: How can the Periodic Table of the Elements and Isotopes help me understand where Ötzi the Iceman lived 5,000 years ago?
The story of Ötzi is a good example of how stable isotopes, radioactive isotopes, and isotopic abundances can be invaluable in scientific detective work. As you read earlier, Ötzi's mummified body was found in the Alps, and fundamental data about isotopes of several elements gave important insights into where he lived.
An analysis of Ötzi's clothing and equipment gave an idea of how he lived, and the contents of his digestive tract revealed what kind of meals he had eaten just prior to his death. Investigation of his body revealed tattoos on arthritic joints, inspiring many hypotheses about the medicine of the time. The story of his death captured the attention of many, and debates over how the arrow head became embedded in his shoulder might never be resolved. None of this could definitively tell scientists if Ötzi lived in what is now Italy or Austria.
This is where isotopes became useful in decoding Ötzi's story. Using the variation in abundances of both stable isotopes and radiogenic isotopes, scientists were able to learn more about where Ötzi may have lived his life. Work to date has focused on isotopes of oxygen, strontium, and lead. The ratio of 18O atoms to 16O atoms was used to locate the area that provided Ötzi's water source when he was alive. The ratios of strontium and lead isotopes helped to locate the geological area that Ötzi lived in.
Open the IUPAC Periodic Table of the Elements and Isotopes Learning Tool and explore oxygen, strontium, and lead isotopes by clicking on the element and then selecting 'more information.' Use these documents to answer the following questions.
Are the isotopes listed below radioactive or stable? Are they radiogenic? If they are radiogenic, state what isotopes decayed to produce them.
- 18O and 16O