These include preservatives used in conversation such as wax, varnish, glue, or insecticides and hydrocarbons.In many cases we may be able to remove the contaminants if we know about them.
For soils and sediments the carbon content varies greatly.
If the % carbon is unknown then please contact us about conducting testing a sample first.
For samples with sufficient sample material remaining after AMS analysis, stable isotopes (N) and C to N ratios will be measured on our EA-IRMS as a further test of collagen quality. Wood & Charcoal: As trees can be long-lived, wood and charcoal may have an in-built age associated with them If possible, either small twigs or outer rings of the tree should be selected for dating.
If these are not available then short-lived species should be selected if possible; identifications must be done before samples are sent for radiocarbon dating.
Marine Samples Marine samples have approximately a 400 year offset from contemporaneous terrestrial samples due to the Marine Reservoir Effect (MRE).
This can be corrected for in calibration using radiocarbon ages of modern (pre-nuclear testing) shells which have been measured for many regions of the ocean.If macrofossils are not available, bulk peat samples can be analysed.Please remove any roots from bulk samples before sending them.Generally monospecific planktonic samples are selected for this purpose.Contaminants: Please indicate on the submission form if there are any known contaminants which could effect the radiocarbon age.If at all possible, fragile macrofossils that would not have survived transport are preferred.