Text Alternative for Radiocarbon Dating Figure 25
An accessible text alternative for figure 25 of a flow diagram to illustrate the steps needed when deciding which materials should be dated from organic sediment.
Split the sediment.
Can horizontally bedded macros be identified in the sample?
If yes, pick them manually from a known 10 millimetre spit.
Are the macro fossils non-terrestrial?
If yes, be afraid.
If not, does any single macro fossil weigh more than 60mg?
If yes, are they twigs?
If not, submit a single macro fossil and consider duplicates as part of risk mitigation.
If they are twigs, then consider the hydrology of the site. Is it inwashed, for example in a river channel?
If there are no terrestrial macrofossils more than 60mg, then can the same items of the same species be bulked so that they weigh more than 60mg?
If so, then submit bulk macrofossils samples from a single species. This is a second choice.
If not, can you bulk macrofossils of a different species so that you come to 60mg? If so, submit bulk macrofossils of more than one species. This is a third choice sample.
If you cannot find a horizontally bedded macros in the sample, sieve 10 millimetre slice in water.
Are there plant macrofossils present in the flot?
If yes, are any of the macrofossils non-terrestrial?
If yes, be afraid.
If not, are there single terrestrial macrofossils weighing more than 60mg?
If yes, are they twigs?
If not, submit a single macrofossils and consider duplicates as part of risk mitigation.
If they are twigs then consider the hydrology of the site. Is it inwashed and it is a river channel for example?
If there are no single terrestrial macrofossils weighing more than 60mg, can items of the same species be bulked to make a sample that weighs 60mg?
If yes, submit a bulk macro sample from a single species as a second choice?
If not, can you bulk macrofossils of different species to make a sample that weighs 60mg?
If so, submit bulk macrofossils of more than one species. This is a third choice sample.
If there are no plant macrofossils present in the flot, then retain the residue and proceed as for a bulk sediment sample.
For a bulk sediment sample, is the underlying geology alkaline?
If yes, date the humin fraction.
If not, does the catchment contain 'old peat'?
If yes, date the humin fraction.
If not, date the humic or humin fraction.
