Carbonate14C Background: Does It Have Multiple Personalities?
| Autor: | Marie-Josée Nadeau, Pieter Meiert Grootes, Frank Bruhn, Antje H L Voelker, Angelika Oriwall, Alexander Duhr |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
010506 paleontology
Archeology Provenance 060102 archaeology biology Mineralogy 06 humanities and the arts Contamination biology.organism_classification 01 natural sciences law.invention Foraminifera chemistry.chemical_compound chemistry law Biogenic carbonate General Earth and Planetary Sciences Carbonate 0601 history and archaeology Sample preparation Radiocarbon dating Geology 0105 earth and related environmental sciences |
| Zdroj: | Radiocarbon. 43:169-176 |
| ISSN: | 1945-5755 0033-8222 |
| Popis: | Measurements of the radiocarbon concentration of several carbonate background materials, either mineral (IAEA C1 Carrara marble and Icelandic double spar) or biogenic (foraminifera and molluscs), show that the apparent ages of diverse materials can be quite different. Using 0.07 pMC obtained from mineral samples as a processing blank, the results from foraminifera and mollusc background samples, varying from 0.12 to 0.58 pMC (54.0-41.4 ka), show a species-specific contamination that reproduces over several individual shells and foraminifera from several sediment cores. Different cleaning attempts have proven ineffective, and even stronger measures such as progressive hydrolization or leaching of the samples prior to routine preparation, did not give any indication of the source of the contamination. In light of these results, the use of mineral background material in the evaluation of the age of older unknown samples of biogenic carbonate (>30 ka) proves inadequate. The use of background samples of the same species and provenance as the unknown samples is essential, and if such material is unavailable, generic biogenic samples such as mixed foraminifera samples should be used. The description of our new modular carbonate sample preparation system is also introduced. |
| Databáze: | OpenAIRE |
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