An expanded radiocarbon age calibration procedure to correct for the marine reservoir effect in mixed marine and terrestrial samples

The “calibration” of arbitrarily defined (in some sense, “conventional”) ages, given in conventional radiocarbon years BP, is now becoming necessary because the term “radiocarbon age” is used less often in archaeological and Quaternary practice. The standard calibration procedure is inappropriate here because Mangerud's boundaries are not measurement results. Thus, another approach to the problem is proposed in order to model the natural situation of many, uniformly distributed, dated samples, which should be similarly divided by the original and “calibrated” boundary. However, the result depends on the value of the typical measurement error and is not unequivocal.

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Variation in Radiocarbon Age Determinations from the Crystal River Archaeological Site, Florida

Radiocarbon ◽

10.2458/56.16960 ◽

2014 ◽

Vol 56 (2) ◽

pp. 801-810 ◽

Cited By ~ 16

Author(s):

Alexander Cherkinsky ◽

Thomas J Pluckhahn ◽

Victor D Thompson

Keyword(s):

Gulf Coast ◽

Archaeological Site ◽

Bone Collagen ◽

Shell Midden ◽

Long Distance ◽

Reservoir Effect ◽

Radiocarbon Age ◽

Soil Charcoal ◽

Crystal River ◽

Age Determinations

Archaeologists interested in radiocarbon dating shell midden sites express concern regarding the accuracy of shell dates and how such determinations should be interpreted. This article discusses the problem of dating shells from sites in the southeastern United States. New results are presented comparing shell, bone, and soil-charcoal age determinations from the Crystal River site, located along the west-central Gulf Coast of Florida. Crystal River is a large multimound site whose occupants engaged in long-distance exchange throughout eastern North America during the Woodland period (∼1000 BC to AD 1050). In the summer of 2012, test units were excavated in several contexts at the site, including both mounds and occupation areas. Samples were collected for 14C dating, which were then processed at the University of Georgia Center for Applied Isotope Studies. This article focuses on samples from the stratified shell midden, from which it was hoped to construct a local correction for marine shell that could be used to date other contexts. The soil-charcoal and bone collagen from these samples have very similar ages (bone samples ranging from about 100 cal BC to cal AD 530 and soil-charcoal from cal AD 345 to 560); however, the shell samples collected from the same stratigraphic units are significantly older than the terrestrial dates (ranging from 1300 to 390 cal BC). The difference in calibrated ages between organic materials and the shells ranges between 560 to 1140 yr. This phenomenon cannot be explained solely by the marine reservoir effect. It appears that all the shell samples formed in mixed marine (∼50–60%) contexts, as indicated by the stable isotope ratios and the amount of atmospheric carbon remaining in the samples. The age of the shell samples cannot be used to date archaeological events as they are influenced not only by the marine reservoir effect, but also the local hardwater effect, which makes them significantly older.

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Radiocarbon Age Calibration of Marine Samples Back to 9000 Cal Yr BP

Radiocarbon ◽

10.1017/s0033822200060264 ◽

1986 ◽

Vol 28 (2B) ◽

pp. 980-1021 ◽

Cited By ~ 510

Author(s):

Minze Stuiver ◽

G W Pearson ◽

Tom Braziunas

Keyword(s):

Special Issue ◽

Reservoir Effect ◽

Radiocarbon Age ◽

Marine Samples ◽

Calibration Curves ◽

Age Correction ◽

The Difference ◽

Reservoir Age ◽

Age Determinations

Calibration curves spanning several millennia are now available in this special issue of Radiocarbon. These curves, nearly all derived from the 14C age determinations of wood samples, are to be used for the age conversion of samples that were formed through use of atmospheric CO2. When samples are formed in reservoirs (eg, lakes and oceans) that differ in specific 14C content from the atmosphere, an age adjustment is needed because a conventional 14C age, although taking into account 14C (and 13C) fractionation, does not correct for the difference in specific 14C activity (Stuiver & Polach, 1977). The 14C ages of samples grown in these environments are too old, and a reservoir age correction has to be applied. This phenomenon has been referred to as the reservoir effect (Stuiver & Polach, 1977).

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Radiocarbon Age Offset Between Shell and Plant Pairs in the Holocene Sediments Under Hakata Bay, Western Japan

Radiocarbon ◽

10.1017/rdc.2016.124 ◽

2017 ◽

Vol 59 (2) ◽

pp. 423-434 ◽

Cited By ~ 4

Author(s):

Toshimichi Nakanishi ◽

Wan Hong ◽

Shoichi Shimoyama ◽

Shin’ichi Sato ◽

Gyujun Park ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Terrestrial Plants ◽

Drilling Tool ◽

Reservoir Effect ◽

Radiocarbon Age ◽

Continuous Coverage ◽

Holocene Sediments ◽

Western Japan ◽

Filter Feeders

AbstractTo measure chronological changes in the marine reservoir effect in western Japan, 47 marine shells and 35 terrestrial plants from the same horizons in two cores of Holocene sediments were radiocarbon dated by the KIGAM AMS facility. These cores were obtained from the central and northern parts of Hakata Bay using a Geoslicer device. This drilling tool provided us continuous coverage and many samples. In order to determine the species effects on the marine reservoir effect, both filter feeders and a deposit feeder were selected for study. Based on the analysis of lithology, mollusk assemblage, and 14C dating, two sedimentary units were determined: the upper bay floor sediment and lower estuarine sediment. Reservoir ages of 280±150 yr (n=17) and 340±140 yr (n=18) were obtained from the central and northern parts of Hakata Bay during 2000 to 10,000 cal BP, respectively. Based on these results, it is clear that a paleoenvironmental change occurred here as a result of sea-level rise during the deglacial period.

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Variation in Radiocarbon Age Determinations from the Crystal River Archaeological Site, Florida

Radiocarbon ◽

10.1017/s0033822200049833 ◽

2014 ◽

Vol 56 (02) ◽

pp. 801-810 ◽

Cited By ~ 2

Author(s):

Alexander Cherkinsky ◽

Thomas J Pluckhahn ◽

Victor D Thompson

Keyword(s):

Gulf Coast ◽

Archaeological Site ◽

Bone Collagen ◽

Shell Midden ◽

Long Distance ◽

Reservoir Effect ◽

Radiocarbon Age ◽

Soil Charcoal ◽

Crystal River ◽

Age Determinations

Archaeologists interested in radiocarbon dating shell midden sites express concern regarding the accuracy of shell dates and how such determinations should be interpreted. This article discusses the problem of dating shells from sites in the southeastern United States. New results are presented comparing shell, bone, and soil-charcoal age determinations from the Crystal River site, located along the west-central Gulf Coast of Florida. Crystal River is a large multimound site whose occupants engaged in long-distance exchange throughout eastern North America during the Woodland period (∼1000 BC to AD 1050). In the summer of 2012, test units were excavated in several contexts at the site, including both mounds and occupation areas. Samples were collected for14C dating, which were then processed at the University of Georgia Center for Applied Isotope Studies. This article focuses on samples from the stratified shell midden, from which it was hoped to construct a local correction for marine shell that could be used to date other contexts. The soil-charcoal and bone collagen from these samples have very similar ages (bone samples ranging from about 100 cal BC to cal AD 530 and soil-charcoal from cal AD 345 to 560); however, the shell samples collected from the same stratigraphic units are significantly older than the terrestrial dates (ranging from 1300 to 390 cal BC). The difference in calibrated ages between organic materials and the shells ranges between 560 to 1140 yr. This phenomenon cannot be explained solely by the marine reservoir effect. It appears that all the shell samples formed in mixed marine (∼50–60%) contexts, as indicated by the stable isotope ratios and the amount of atmospheric carbon remaining in the samples. The age of the shell samples cannot be used to date archaeological events as they are influenced not only by the marine reservoir effect, but also the local hardwater effect, which makes them significantly older.

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Modeling the Radiocarbon Reservoir Effect in Lacustrine Systems

Radiocarbon ◽

10.1017/s0033822200043150 ◽

2007 ◽

Vol 49 (3) ◽

pp. 1241-1254 ◽

Cited By ~ 52

Author(s):

Shi-Yong Yu ◽

Ji Shen ◽

Steven M Colman

Keyword(s):

Sediment Cores ◽

Sediment Surface ◽

Relative Importance ◽

Nuclear Testing ◽

Lake Qinghai ◽

Reservoir Effect ◽

Radiocarbon Age ◽

Terrestrial Inputs ◽

Inland Water Body ◽

Autochthonous Production

The modern water (both pre- and post-atmospheric nuclear testing) of most lakes has an anomalously old apparent radiocarbon age due to what is commonly referred to as the “reservoir effect.” In contrast to marine settings, this14C-offset phenomenon is primarily caused by pre-aged carbon discharged to lakes by rivers and/or groundwater. In this paper, a 2-component box model based on the principle of14C mass balance in lake water and in the early diagenesis zone was formulated to address the relative importance of terrestrial inputs, autochthonous production, and biogeochemical processes in the14C reservoir of a lacustrine system. The model was tested using observed data from Lake Qinghai, the largest inland water body in China. Our inverse modeling using Markov chain Monte Carlo (MCMC) techniques yields best estimates of the δ14C of DIC in river (∼118% modern) and groundwater (∼76% modern), as well as the δ14C of DOC in river water (∼70% modern) during the post-bomb era. Assuming that these parameters remain constant over time, our modeling indicates that both the DIC and DOC pool of this lake have reservoir ages of about 1500 yr for the pre-bomb era, generally consistent with estimates obtained by extrapolation of the age-depth models of 2 sediment cores to the sediment surface.

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Radiocarbon Age Offsets Between Living Organisms from the Marine and Continental Reservoir in Coastal Localities of Patagonia (Argentina)

Radiocarbon ◽

10.1017/s0033822200032343 ◽

2003 ◽

Vol 45 (1) ◽

pp. 9-15 ◽

Cited By ~ 17

Author(s):

Roberto R Cordero ◽

Héctor Panarello ◽

Sonia Lanzelotti ◽

Cristian M Favier Dubois

Keyword(s):

Reservoir Effect ◽

Radiocarbon Age ◽

Local Factors ◽

Living Organisms

The radiocarbon of the local reservoir effect (RE) was observed in many sectors along the Argentinean Patagonic coast. Results show variations in the 14C offsets and differences between marine and continental species growing within the same locality, ranging from about 80–1100 yr BP. It is postulated that such variations are mainly due to local factors, including the coast morphology and the contribution of continental waters. The relevance of these kinds of studies for the interpretation of age in archaeological samples is highlighted in this paper.

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Radiocarbon age offsets of Plants and Shells in Holocene sediments from the Sukumo plain, Southwest Coast of Shikoku, Southwest Japan

Radiocarbon ◽

10.1017/rdc.2019.129 ◽

2019 ◽

Vol 61 (6) ◽

pp. 1951-1961 ◽

Cited By ~ 1

Author(s):

Toshimichi Nakanishi ◽

Tomohiro Tsuji ◽

Futoshi Nanayama ◽

Tatsuhiko Yamaguchi ◽

Yasuo Kondo ◽

...

Keyword(s):

Kuroshio Current ◽

River Channel ◽

Philippine Sea Plate ◽

Terrestrial Plants ◽

Eurasian Plate ◽

Southwest Japan ◽

Reservoir Effect ◽

Meandering River ◽

Radiocarbon Age ◽

Holocene Sediments

AbstractTo identify chronological changes in the marine reservoir effect in southwest Japan, the radiocarbon ages of eight pairs of marine shells and terrestrial plants were measured from the same horizons of one core of Holocene sediments. This core was obtained from the northern part of the Sukumo Plain in southwestern Shikoku Island, which faces the warm Kuroshio Current. The drilling site is located in an area of subsidence associated with the convergence of the Philippine Sea Plate and the Eurasian Plate. On analyses of lithology, molluscan assemblages, and radiocarbon dating, we interpreted, from oldest to youngest, nine units: basement rock, a braided river channel, a meandering river channel, an estuary, a transgressive inner bay, Kikai-Akahoya volcanic ash, a deltaic inner bay, a tidal flat, and artificial soil. Changes in the depositional environment were mainly associated with sea-level rise after the end of the last glaciation. The reservoir ages of the eight pairs, 330 ± 70 yr, were obtained from a transgressive inner bay to deltaic inner bay sediments, formed during 4100–9200 cal BP. The chronological change in the reservoir effect allows us to correlate the Sukumo Core sediments with previous results from southwestern Japan, the Korean Peninsula, and Taiwan Island.

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