Radiocarbon Laboratory
PD Dr. Markus Egli Tel. +44 (0)44 635 5184
Ivan Woodhatch Fax +44 (0)44 635 6841
The principles (simplified) behind this type of dating are the following: there are three isotopes of carbon, 12C, 13C and 14C (radiocarbon). 12C and 13C are stable isotopes, 14C is radioactive and thus, unstable. It is produced in the upper atmosphere through the collision of cosmic rays with nitrogen atoms (14N). 14C becomes part of the global carbon cycle and is distributed among the various reservoirs, i.e. land, oceans, lakes, etc. 14C is assimilated by plants during photosynthesis at an almost fixed ratio to 13C and 12C. Once an organism dies it becomes isolated from the 14C source. The "14C clock" now starts because of radioactive decay and the consequent changes in ratio of 14C to 13C and 12C. This change in ratio over time can be used to measure the age of organic samples. Measurable samples have ages of between 150 and 50,000 years old.
Samples
Plant macrofossils, charcoal, wood, peat, seeds, cloth, paper, leather, soil, bone and ivory make up the palette of sample types that we deal although basically, if it's organic it can be dated. In addition, shales (carbonates), lime mortar and some secondary carbonates in sediments and soils may be suitable for dating.
General information
Each sample costs CHF 900 + VAT (all inclusive). There is a reduction if more than 10 samples are submitted together. Academic institutions within Switzerland and International and EU projects have a special rate. Our usual turnaround time is from 3 to 8 weeks (excluding any major accelerator maintenance).