Please remove excess water, wrap the samples with plastic (e.g.
Saran Wrap) to limit air contact, place them in a Ziplock bag, and ship to us.
Alkali extractions on sediments will remove any unbound carbon that is alkali-soluble.
paleobotanist for plants, forensic archaeologist for bones, or paleontologists for shells.
Generally, it is better to date the macrofossils present than the sediment due to the possible contaminants in the latter.
You are welcome to contact us to discuss the pretreatment or request that we contact you after the pretreatment to discuss options for radiocarbon dating. However, knowing the dry weight will better allow you to estimate the amount of material to send.
If you want to dry your samples, heating at 90°C to 100°C for 4-24 hours is recommended.
Note: Our lab does not identify the exact type of macrofossil found in the sediment.
Identification of macrofossils requires highly trained scientists, e.g.– If the macrofossils are chosen for the analysis, the reported results will be as “plant material”.If the sediment is chosen for the analysis, the reported results will be as “bulk organic carbon” or “total acid insoluble organics” depending on the sediment fractions included in the analysis.This is mostly true for sediments that are organic rich (dark black or brown in coloration) as well as for sediments that are not well drained and where water ponds (like swamps, peat bogs, etc).In areas where there is not much rain fall or the sediment is well drained or is low in carbon (light tan or gray sediments), humic acids may not be much of a problem.Most macrofossils can be treated with (1) acid to remove carbonates, and (2) alkali to remove humic acids that might be in the sediment. Sediment and rain water or ground water can move these humic acids up or down through the sedimentary profile bringing carbon that is either younger or older into a sediment layer.