The dynamics of fishing villages along the South Atlantic Coast of North America (ca. 5000-3000 years BP).

We present new chronologies that inform the timing and tempo of shell ring and shell mound construction on the South Atlantic Bight. Our project combines recently acquired dates with legacy radiocarbon dates from over 25 rings and mounds to provide a higher-resolution chronology regarding the occupation and formation of this larger landscape of the earliest fishing villages along the East Coast of the United States. We resolve the ordering and timing of occupation of these rings and mounds through Bayesian statistical modeling. These new models historicize and contextualize these shell rings in ways previously impossible. Specifically, our new chronologies of these villages indicate that the earliest villages were established prior to the invention of pottery. The early period of village establishment evidences isolated village rings, whereas later periods seem to have more villages, but these appear to have been relocated to other areas and/or islands over time. Shell mounds are fewer in number, are spread throughout the time period, and may represent special purpose sites compared to shell-rings. Once villages spread, they quickly adopted new technologies (i.e., pottery) and created new institutions and practiced village relocation, which allowed this way of life to persist for more than a thousand years.

Comparison of radiocarbon techniques for the assessment of biobase content in fuels.

A comparison was made between various radiocarbon measurement techniques for the purpose of quantifying each methods capability for the proper apportionment of biobase-derived additives to gasoline. Measurement techniques include (1) direct liquid scintillation counting, (2) carbon dioxide absorption followed by liquid scintillation counting, (3) conversion to benzene followed by liquid scintillation counting and (4) accelerator mass spectrometry. In addition, stable isotope ratios of carbon and hydrogen were determined to assist in the authentication of a fuels source with regard to petrochemical or biobase origin is required for the confirmation of minimum anti-knock components, consumer awareness and proper assessment for regulatory taxation. Accelerator mass spectrometry was found to be the most precise technique followed by conversion of fuel to benzene with liquid scintillation counting and direct counting by liquid scintillation counting. Finally, liquid scintillation counting of absorbed carbon dioxide was found to be the least precise and should not be used for this analysis. The high to low precisions correlate with the high to low cost of equipment and support required by each of these methods except for direct liquid scintillation counting. Therefore, laboratories interested in developing capability to perform such authentication can use this data to consider the economics of the optimum technique to use for radiocarbon measurement.