Introduction to Dating Methods

Dating methods help us answer the question “When did it happen?”

Dating methods and techniques continue to improve over time and shed light on mysteries buried deep in the past. Each method has its own strengths, but none is perfect. So, experts work together to extract chronological information through applying a diverse range of techniques.

Dating Methods and Examples

• Radiocarbon dating for wood or charcoal pieces or bits of bone and shell (if they are less than 50, 000 years old)
• Luminescence methods for dating sediments when heated to a high temperature or last exposed to sunlight
• Uranium-series methods for dating cave formations (speleothems) and bones
• Electron spin resonance for dating tooth enamel
• Argon dating methods for minerals in volcanic ash

Contamination

“Contamination is around us all the time. So we just need to factor in how much of it’s contaminant and how much of it is real” (Prof. Bert Roberts).

Deposits don’t stay static — they change over time. For example, the weathering and decay of materials and their migration through deposits can result in contamination of artefacts and ecofacts. These variables must be considered when dating deposits, skeletal remains and artefacts. In some instances, such as uranium-series dating of bones, contamination in the form of uranium migration into a bone is used to identify the age of that bone.

Conversation starter

• Why might DNA analysis of Hobbit bones be complex and how may advancing methods address this?