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Marine Radiocarbon Reservoir Effect in Southern Atlantic Iberian Coast

  • José M Matos Martins (a1) (a2) and António M Monge Soares (a1)

Abstract

Research concerning the variability of the marine radiocarbon reservoir effect (ΔR) in the southern Iberian Atlantic coast confirms the existence of different ΔR values for regions that correspond to different oceanographic conditions. Due to these oceanographic conditions, the southern Iberian Atlantic coast can be divided into 3 zones: the Barlavento (windward), where the coastal waters are influenced by an intense upwelling of the northeastern Atlantic circulation (positive ΔR values); the Sotavento (leeward), where an upwelling area of minor intensity occurs; and the Andalusian coast, where because of its configuration does not present any wind-driven coastal upwelling (negative ΔR values). For the first time, ΔR values were determined for the Sotavento coastal region and, at the same time, new ΔR values were calculated for the Barlavento and the Andalusian coast for the last 3000 yr taking into account the data already obtained but now using a new methodology for calculation. In this way, ΔR weighted mean values were determined for the 3 regions of the southern Iberian Atlantic coast: ΔR = +69 ± 17 14C yr (Barlavento), ΔR = −26 ± 14 14C yr (Sotavento), and ΔR = −108 ± 31 14C yr (Andalusian coast). These values are in accordance with the different oceanographic conditions prevailing in these coastal regions. The data also allow identification of a Bond event at 0.8 ka cal BP and a drastic change in the oceanographic conditions in the Barlavento and Andalusian coastal areas during the 5th millennium cal BP.

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Corresponding author

Corresponding author. Email: jmartins@ctn.ist.utl.pt.

References

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Arruda, AM, Soares, AMM, Freitas, VT, Oliveira, CF, Martins, JMM, Portela, PC. In press. A cronologia relativa e absoluta da ocupação Sidérica do Castelo e Castro Marim. XELB 12. In Portuguese.
Ascough, PL, Cook, GT, Dugmore, AJ. 2005. Methodological approaches to determining the marine radiocarbon reservoir effect. Progress in Physical Geography 29(4):532–47.
Ascough, PL, Cook, GT, Dugmore, AJ, Scott, EM. 2007. The North Atlantic marine reservoir effect in the Early Holocene: implications for defining and understanding MRE values. Nuclear Instruments and Methods in Physics B 259(1):438–47.
Ascough, PL, Cook, GT, Dugmore, AJ. 2009. North Atlantic marine 14C reservoir effects: implications for late-Holocene chronological studies. Quaternary Geochronology 4(3):171–80.
Bronk Ramsey, C. 2009. Bayesian analysis of radiocarbon dates. Radiocarbon 51(1):337–60.
deMenocal, PB, Ortiz, J, Guilderson, T, Sarnthein, M. 2000. Coherent high- and low-latitude climate variability during the Holocene warm period. Science 288(5474):2198–202.
Diffenbaugh, NS, Sloan, LC, Snyder, MA. 2003. Orbital suppression of wind-driven upwelling in the California Current at 6 ka. Paleoceanography 18:1051, doi:10.1029/2002PA000865.
Ferreira, DB. 1984. Le Systeme Climatique de l'Upwelling Ouest Iberique. [Report #19 of the Linha de Acção de Geografia Física], Lisbon: Centro de Estudos Geográficos. INIC. 92 p.
Fiúza, AFG. 1982. The Portuguese coastal upwelling system. In: Actual Problems of Oceanography in Portugal. Lisbon: Junta Nacional de Investigação Científica e Tecnológica. p 4571.
Fiúza, AFG. 1983. Upwelling patterns off Portugal. In: Suess, E, Thiede, J, editors. Coastal Upwelling. Its Sediment Record. New York: Plenum. p 8598.
Fiúza, AFG, Macedo, ME, Guerreiro, MR. 1982. Climatological space and time variation of the Portuguese coastal upwelling. Oceanologica Acta 5:3140.
Ingram, BL. 1998. Differences in radiocarbon age between shell and charcoal from a Holocene shellmound in northern California. Quaternary Research 49(1):102–10.
Kennett, DJ, Ingram, BL, Erlandson, JM, Walker, P. 1997. Evidence for temporal fluctuations in marine radiocarbon reservoir ages in the Santa Barbara Channel, southern California. Journal of Archaeological Science 24(11):1051–9.
Martins, JMM, Martín, AM, Portela, PJC, Soares, AMM. 2012. Improving the 14C dating of marine shells from the Canary Islands for constructing more reliable and accurate chronologies. Radiocarbon 54(3–4):943–52.
Reimer, PJ, McCormac, G, Moore, J, McCormick, F, Murray, EV. 2002. Marine radiocarbon reservoir corrections for the mid- to late Holocene in the eastern subpolar North Atlantic. The Holocene 12(2): 129–35.
Reimer, PJ, Baillie, MGL, Bard, E, Bayliss, A, Beck, JW, Blackwell, PG, Bronk Ramsey, C, Buck, CE, Burr, GS, Edwards, RL, Friedrich, M, Grootes, PM, Guilderson, TP, Hajdas, I, Heaton, T, Hogg, AG, Hughen, KA, Kaiser, KF, Kromer, B, McCormac, FG, Manning, SW, Reimer, RW, Richards, DA, Southon, JR, Talamo, S, Turney, CSM, van der Plicht, J, Weyhenmeyer, CE. 2009. IntCal09 and Marine09 radiocarbon age calibration curves, 0–50,000 years cal BP. Radiocarbon 51(4): 1111–50.
Rogerson, M, Rohling, EJ, Weaver, PPE, Murray, JW. 2004. The Azores Front since the Last Glacial Maximum. Earth and Planetary Science Letters 222(3–4):779–89.
Russell, N, Cook, GT, Ascough, PL, Scott, EM, Dugmore, AJ. 2011. Examining the inherent variability in ΔR: new methods of presenting ΔR values and implications for MRE studies. Radiocarbon 53(2):277–88.
Soares, AMM. 1989. O Efeito de Reservatório Oceânico nas Águas Costeiras de Portugal Continental. Sacavém: Instituto de Ciências e Engenharia Nucleares. Instituto Nacional de Engenharia e Tecnologia Industrial. 135 p. In Portuguese.
Soares, AMM. 1993. The 14C content of marine shells: evidence for variability in coastal upwelling off Portugal during the Holocene. In: Isotope Techniques in the Study of Past and Current Environmental Changes in the Hydrosphere and the Atmosphere. Vienna: IAEA. p 471–85.
Soares, AMM. 2005. Variabilidade do “Upwelling” Costeiro durante o Holocénico nas Margens Atlânticas Ocidental e Meridional da Península Ibérica [PhD dissertation]. Faro: Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve. In Portuguese.
Soares, AMM. 2010. Comment on “Formation of chenier plain of the Doñana marshland (SW Spain): Observations and geomorphic model” by A. Rodríguez-Ramírez and C.M. Yáñez-Camacho. [Marine Geology 254 (2008) 187–196]. Marine Geology 275(1–4):287–89.
Soares, AMM, Dias, JMA. 2006a. Coastal upwelling and radiocarbon—evidence for temporal fluctuations in ocean reservoir effect off Portugal during the Holocene. Radiocarbon 48(1):4560.
Soares, AMM, Dias, JMA. 2006b. Once upon a time…the Azores Front penetrated into the Gulf of Cadiz. In: Proceedings of the 5th Symposium on the Iberian Atlantic Margin. Aveiro: Universidade de Aveiro. p 205–6.
Soares, AMM, Dias, JMA. 2007. Reservoir effect of coastal waters off western and northwestern Galicia. Radiocarbon 49(2):925–36.
Soares, AMM, Martins, JMM. 2009. Radiocarbon dating of marine shell samples. The marine radiocarbon reservoir effect of coastal waters off Atlantic Iberia during Late Neolithic and Chalcolithic periods. Journal of Archaeological Science 36(12):2875–81.
Soares, AMM, Martins, JMM. 2010. Radiocarbon dating of marine samples from Gulf of Cadiz: the reservoir effect. Quaternary International 221(1–2):912.
Stuiver, M, Braziunas, TF. 1993. Modeling atmospheric 14C influences and 14C ages of marine samples to 10,000 BC. Radiocarbon 35(1):137–89.
Stuiver, M, Polach, HA. 1977. Discussion: reporting of 14C data. Radiocarbon 19(3):355–63.
Stuiver, M, Pearson, GW, Braziunas, T. 1986. Radiocarbon age calibration of marine samples back to 9000 cal yr BP. Radiocarbon 28(2B):9801021.
Vargas, JM, García-Lafuente, J, Delgado, J, Criado, F. 2003. Seasonal and wind-induced variability of sea surface temperature patterns in the Gulf of Cádiz. Journal of Marine Systems 38:205–19.

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