2008 Levy et al PNAS Supporting Information

Radiocarbon, 2006

Peat samples from Rio Grande holocenic terraces of La Poma, Humahuaca, Jujuy (23°17'S, 65°42'W), 3600 m as!.

: Ring dates and radiocarbon ( 14 C) dates for four tree species from a wet tropical forest in Cameroon. For each of the species 3-4 samples were analysed. Ring dates were determined by counting rings back in time from the bark. Radiocarbon dates were determined with the program CALIbomb (http://intcal.qub.ac.uk/CALIBomb), using the fraction of 14 C (±sd) in the wood (measured by Accelerator Mass Spectometry on holocellulose) using the NH_Zone3 ). Positive differences indicates that ring dates were overestimated (i.e. false rings) and negative differences indicate and underestimation of the date (i.e. missing rings). Percentages of rings missed was calculated as the amount of rings missed per measurement and the period over which these rings were missed (average percentages calculated over all measurements per species). *For E. utile amount of rings missed was within the measurement accuracy of radiocabon dating and percentages were not calculated.

Memoirs of the Society for American Archaeology, 1951

The Preceding discussions have considered the radiocarbon dates in relation to a number of archaeological, geological, and palynological problems. It remains to consider the endeavor as a whole, and to reach some conclusions concerning its present and future value and usefulness. Of primary importance is a consideration of what the dates mean. Basic to this is an understanding of the statistics involved. At the request of the Committee, Arnold, who has been intimately associated with the project, has kindly contributed the following explanatory paragraphs:It seems worth while to review briefly the physical…

Journal of …, 2009

Science, 2012

Dating Carbon Radiocarbon dating is the best way to determine the age of samples that contain carbon and that are younger than ∼50,000 years, the limit of precision for the method. There are several factors that complicate such age determinations, however, some of the most important of which include variability of the 14 C production in the atmosphere (which affects organic samples whose radiocarbon inventories are derived from atmospheric CO 2 ), surface ocean reservoir effects (which affect marine samples that acquire their radiocarbon signatures from seawater), and variable dead carbon fraction effects (which affect speleothems that derive their carbon from groundwaters). Bronk Ramsey et al. (p. 370 ; see the Perspective by Reimer ) avoid the need to make such assumptions, reporting the 14 C results of sediments from Lake Suigetsu, Japan. Analysis of terrestrial plant macrofossils in annually layered datable sediments yielded a direct record of atmospheric radiocarbon for the ent...

Seeds of Western Culture, 2023

The process that created the dendrochronology-based radiocarbon calibration curve is demonstrated to be a flawed non-scientific process that relied on circular arguments. When the calibration curve is dismissed scientific radiocarbon dates correspond with the Low Chronology, matching the 1406 BC date for the Eruption of Thera during the reign of Ahmose.

A Report of Internship done at Birbal Sahini Institute of Palaeobotany