The direct carbonate procedure for accelerator mass spectrometry radiocarbon (AMS 14C) dating of submilligram samples of biogenic carbonate without graphitization is becoming widely used in a variety of studies. We compare the results of 153 paired direct carbonate and standard graphite 14C determinations on single specimens of an assortment of biogenic carbonates. A reduced major axis regression shows a strong relationship between direct carbonate and graphite percent Modern Carbon (pMC) values (m = 0.996; 95% CI [0.991-1.001]). An analysis of differences and a 95% confidence interval on pMC values reveals that there is no significant difference between direct carbonate and graphite pMC values for 76% of analyzed specimens, although variation in direct carbonate pMC is underestimated. The difference between the two methods is typically within 2 pMC, with 61% of direct carbonate pMC measurements being higher than their paired graphite counterpart. Of the 36 specimens that did yield significant differences, all but three missed the 95% significance threshold by 1.2 pMC or less. These results show that direct carbonate 14C dating of biogenic carbonates is a cost-effective and efficient complement to standard graphite 14C dating.
Titolo: | COMPARING DIRECT CARBONATE and STANDARD GRAPHITE 14C DETERMINATIONS of BIOGENIC CARBONATES | |
Autore/i: | Bright J.; Ebert C.; Kosnik M. A.; Southon J. R.; Whitacre K.; Albano P. G.; Flores C.; Frazer T. K.; Hua Q.; Kowalewski M.; Martinelli J. C.; Oakley D.; Parker W. G.; Retelle M.; Do Nascimento Ritter M.; Rivadeneira M. M.; Scarponi D.; Yanes Y.; Zuschin M.; Kaufman D. S. | |
Autore/i Unibo: | ||
Anno: | 2021 | |
Rivista: | ||
Digital Object Identifier (DOI): | http://dx.doi.org/10.1017/RDC.2020.131 | |
Abstract: | The direct carbonate procedure for accelerator mass spectrometry radiocarbon (AMS 14C) dating of submilligram samples of biogenic carbonate without graphitization is becoming widely used in a variety of studies. We compare the results of 153 paired direct carbonate and standard graphite 14C determinations on single specimens of an assortment of biogenic carbonates. A reduced major axis regression shows a strong relationship between direct carbonate and graphite percent Modern Carbon (pMC) values (m = 0.996; 95% CI [0.991-1.001]). An analysis of differences and a 95% confidence interval on pMC values reveals that there is no significant difference between direct carbonate and graphite pMC values for 76% of analyzed specimens, although variation in direct carbonate pMC is underestimated. The difference between the two methods is typically within 2 pMC, with 61% of direct carbonate pMC measurements being higher than their paired graphite counterpart. Of the 36 specimens that did yield significant differences, all but three missed the 95% significance threshold by 1.2 pMC or less. These results show that direct carbonate 14C dating of biogenic carbonates is a cost-effective and efficient complement to standard graphite 14C dating. | |
Data stato definitivo: | 2022-01-14T19:38:58Z | |
Appare nelle tipologie: | 1.01 Articolo in rivista |