Some species of molluscs may ingest limestone which can cause an age offset but may be fine in non-calcareous regions.The shells of foraminifera are also often radiocarbon dated to provide ages for marine sediment cores.
Bulk peat samples should be dried or stored in a cool, dark place.
Do not wrap them in aluminum foil because the acidic nature of the peat will cause it to disintegrate.
If macrofossils are not available, bulk peat samples can be analysed.
Please remove any roots from bulk samples before sending them.
The MRE may also vary over time which adds some uncertainty to the calibrated age range.
The most reliable molluscs to radiocarbon date are bivalves since many of these feed directly on plankton in the ocean although burrowing species should be avoided.
Sample size If at all possible, please send only the amount required for the radiocarbon dating.
Minimum and optimum weights are given in the table below.
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.
Soil Because soil is not a 'closed' system, it is not a good choice for radiocarbon dating, unless it is for the purpose of carbon storage and turnaround studies.