¹⁴C and Marine Reservoir Effect in Archaeological Samples from the Northeast Gulf of California

Abstract

Previous studies of live-collected pre-weapons testing mollusk shells in the northern Gulf of California have demonstrated that the local radiocarbon reservoir effect (ΔR) is large and highly variable. To test the validity of this observation for paired charcoal and shell samples from archaeological contexts, we dated samples from four shell midden locations and six midden layers from the eastern shoreline of the Gulf of California near Puerto Peñasco, Sonora, Mexico. Dated charcoal samples were small twigs or brushy plants used to cook shellfish and the shells dated within each midden showed signs of burning. Ages range from approximately 5700 to 1900 cal BP. The offset between the modeled marine 14C age for calibrated ages of the middens and measured shell 14C age (ΔR) averaged 425 yr with a standard deviation of 115 yr.

The Worldwide Marine Radiocarbon Reservoir Effect: Definitions, Mechanisms, and Prospects

“…In any case, samples must be selected with extreme care in order to assure contemporaneity (see , for the major factors for consideration when using this approach). There are a number of MRE studies that have employed the paired sample methodology to determine ΔR corrections (e.g., Albero et al, 1986;Dettman et al, 2015;Facorellis, 1998;Hadden & Cherkinsky, 2017;Head et al, 2016;Latorre et al, 2017;Nakamura, 2007;Owen, 2002;Southon et al, 1995;Southon & Fedje, 2003). The atmospheric counterpart of marine samples in these studies is generally charcoal, but recent work has been done employing land snail shells (see Macario, Alves, Chanca, et al, 2016)-it has been shown that some species are reliable proxies for the atmospheric carbon reservoir (see Macario, Alves, Carvalho et al, 2016)-and terrestrial mammal bones (see, e.g., Ascough, Cook, Church, et al, 2007;Ascough, Cook, Dugmore, & Scott, 2007) for that purpose.…”

Lake and mire isolation data set for the estimation of post-glacial land uplift in Fennoscandia

“…These kinds of samples have been collected especially in the area of Finland and Sweden. In Finland, the main data contributors have been Matti Eronen and Gunnar Glückert (Eronen et al, 2001). Arto Vuorela collected additional data points and in- cluded the data set of Matti Eronen and Gunnar Glückert into his own data set, published in Vuorela et al (2009).…”

“…The historical land uplift rate in Fennoscandia has been studied using information on lake isolation from the sea. Eronen et al (2001) and Cato (1992) examined the isolation of several lakes using sediment samples taken from the bottom of the lakes. The samples were dated using the 14 C radiocarbon dating method, and the age and depth of the layer where saltwater algae changed into freshwater algae were determined.…”

“…In addition, there are geological interpretations of the retreat of the Ancylus Lake and the Baltic Ice Lake drawn from mire studies (e.g. Eronen et al, 2001;Mäkilä et al, 2013).…”

Lake and mire isolation data set for the estimation of post-glacial land uplift in Fennoscandia

“…However, when using shoreline modeling, these burials appear to be several meters below the sea level at the time the remains are dated to. Either the shoreline displacement model is incorrect or the 'Marine reservoir effect' (Dettman et al, 2015;Philippsen, 2013;Reimer and Reimer, 2006) has had an influence on the samples.…”