Skip to main content Accessibility help

Aragonite Fraction Dating of Vermetids in the Context of Paleo Sea-Level Curves Reconstruction

  • Vinicius N Moreira (a1), Kita D Macario (a1) (a2), Renato B Guimarães (a3), Fábio F Dias (a2), Julia C Araujo (a2), Perla Jesus (a2) and Katerina Douka (a4) (a5)...


Identifying and tackling recrystallization is a critical factor in the reliable radiocarbon (14C) dating of carbonates, since exogenous carbon can be incorporated and thus mask the real age of the samples. Vermetids are among the most important bioindicators used for paleo sea-level reconstruction, and the accuracy of their chronology can significantly impact sea-level curves. Age differences larger than 1 14C kyr before and after acid etching, combined with X-ray diffraction (XRD) analysis that indicates a significant amount of calcite still remains in the shell, led us to apply the previously developed carbonate density separation protocol (CarDS). Using a solution of sodium polytungstate, with density of 2.80 g/cm3, we successfully separated different carbonate fractions for a set of 10 vermetid samples from the coast of Rio de Janeiro, southeast of Brazil. Each separation was verified by XRD analysis and the 14C concentrations of different fractions were compared. The results show that the calcite fraction in the studied vermetid samples varied from 12 to 63% and aragonite fraction ages are up to 2 14C kyr older than the raw samples, thus confirming the efficacy of CarDS in removing young carbonates and the importance of density separation to vermetids prior to accelerator mass spectrometry (AMS) dating.


Corresponding author

*Corresponding author. Email:


Hide All
Angulo, RJ, de Souza, MC. 2014. Revisão conceitual de indicadores costeiros de paleoníveis marinhos quaternários no Brasil. Quat. Environ. Geosci. 5.
Angulo, RJ, Pessenda, LCR, de Souza, MC. 2002. O significado das datações ao 14C na reconstrução de paleoníveis marinhos e na evolução das barreiras quaternárias do litoral paranaense. Rev. Bras. Geociências 32:95106.10.25249/0375-7536.200232195106
Baker, RGV, Haworth, RJ. 2000. Smooth or oscillating late Holocene sea-level curve? Evidence from cross-regional statistical regressions of fixed biological indicators. Mar. Geol. 163: 353365.10.1016/S0025-3227(99)00117-6
Bathurst, RGC. 1972. Carbonate sediments and their diagenesis. Elsevier.
Brock, F, Higham, T, Ditchfield, P, Ramsey, CB. 2010. Current pretreatment methods for AMS radiocarbon dating at the Oxford Radiocarbon Accelerator Unit (ORAU). Radiocarbon. 52(1):103112.10.1017/S0033822200045069
Burton, Elizabeth A, Walter, LM. 1987. Relative precipitation rates of aragonite and Mg calcite from seawater: Temperature or carbonate ion control? Geology 15.2:111114.10.1130/0091-7613(1987)15<111:RPROAA>2.0.CO;2
Castro, JWA, Suguio, K, Seoane, J, Cunha, AM, Dias, FF. 2014. Sea-level fluctuations and coastal evolution in the state of Rio de Janeiro, southeastern Brazil. An. Acad. Bras. Cienc. 86: 671683.10.1590/0001-3765201420140007
Cherkinsky, A, Culp, RA, Dvoracek, DK, Noakes, JE. 2010. Status of the AMS facility at the University of Georgia. Nuclear Instruments and Methods in Physics Research B 268:867870.10.1016/j.nimb.2009.10.051
Douka, K, Hedges, REM, Higham, TFG. 2010. Improved AMS 14C dating of shell carbonates using high-precision X-ray diffraction and a novel density separation protocol (CarDS). Radiocarbon 52:735751.10.1017/S0033822200045756
Edwards, RL, Cheng, H, Cutler, KB, Gallup, CD, Richards, DA. 2013. Geochemical evidence for Quaternary sea-level changes. In: Treatise on geochemistry. 2nd ed. Elsevier.
Friedman, GM. 1959. Identification of carbonate minerals by staining methods. Journal of Sedimentary Research 29:8797.
Fyfe, WS, Bischoff, JL. 1965. The calcite-aragonite problem. Soc. Econ. Paleont. Mineral. Spec. Publ. 13:313. doi: 10.2110/pec.65.07.0003.
Jamieson, JC. 1953. Phase equilibrium in the system calcite-aragonite. J. Chem. Phys. 21:13851390.10.1063/1.1699228
Jesus, PB, Dias, FF, de Azeredo Muniz, R, Macário, KCD, Seoane, JCS, Quattrociocchi, DGS, Cassab, R de CT, Aguilera, O, de Souza, RCCL, Alves, EQ. 2017. Holocene paleo-sea level in southeastern Brazil: an approach based on vermetids shells. J. Sediment. Environ. 2, 3548.
Kelletat, D. 2006. Beachrock as sea-level indicator? Remarks from a geomorphological point of view. J. Coast. Res. 15581564.10.2112/04-0328.1
Kominz, MA. 2001. Sea level variations over geologic time. In: Encyclopedia of ocean sciences. 2nd ed. Academic Press. p. 185193.10.1016/B978-012374473-9.00255-1
Laborel, J, Laborel-Deguen, F. 2005. Sea-level indicators, biologic. In: Encyclopedia of coastal science. Springer. p. 833834.
Leorri, E, Fatela, F, Drago, T, Bradley, SL, Moreno, J, Cearreta, A. 2013. Lateglacial and Holocene coastal evolution in the Minho estuary (N Portugal): Implications for understanding sea-level changes in Atlantic Iberia. The Holocene 23:353363.10.1177/0959683612460786
Linares, R, Macario, KD, Santos, GM, Carvalho, C, dos Santos, HC, Gomes, PRS, Castro, MD, Oliveira, FM, Alves, EQ. 2015. Radiocarbon measurements at LAC-UFF: Recent performance. Nuclear Instruments and Methods in Physics Research B 361:341345.10.1016/j.nimb.2015.05.025
Loftus, E, Rogers, K, Lee-Thorp, J. 2015. A simple method to establish calcite: aragonite ratios in archaeological mollusc shells. Journal of Quaternary Science 30(8):731735.10.1002/jqs.2819
Lowenstam, HA, Weiner, S. 1989. On biomineralization. Oxford University Press on Demand.
Macario, KD, Alves, EQ, Moreira, VN, Oliveira, FM, Chanca, IS, Jou, RM, Diaz, M. 2017. Fractionation in the graphitization reaction for 14C-AMS analysis: The role of Zn× the role of TiH2. International Journal of Mass Spectrometry 423:3945.10.1016/j.ijms.2017.10.005
Macario, KD, Oliveira, FM, Carvalho, C, Santos, GM, Xu, X, Chanca, IS, Alves, EQ, Jou, RM, Oliveira, MI, Pereira, BB. 2015. Advances in the graphitization protocol at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil. Nuclear Instruments and Methods in Physics Research B 361:402405.10.1016/j.nimb.2015.03.081
Martin, L, Dominguez, JML, Bittencourt, ACSP. 2003. Fluctuating Holocene sea levels in eastern and southeastern Brazil: evidence from multiple fossil and geometric indicators. Journal of Coastal Research:101124.
Morse, JW, Wang, Q, Tsio, MY. 1997. Influences of temperature and Mg: Ca ratio on CaCO3 precipitates from seawater. Geology 25:8587.10.1130/0091-7613(1997)025<0085:IOTAMC>2.3.CO;2
Pirazzoli, PA. 2005. Sea-level indicators, geomorphic. In: Encyclopedia of coastal science. Springer. p. 836838.
Pluet, J, Pirazzoli, PA. 1991. World atlas of Holocene sea-level changes. Elsevier.
Psuty, NP. 1988. Sediment budget and dune/beach interaction. Journal of Coastal Research: 14.
Strachan, KL, Finch, JM, Hill, T, Barnett, RL. 2014. A late Holocene sea-level curve for the east coast of South Africa. S. Afr. J. Sci. 110:19.10.1590/sajs.2014/20130198
Suguio, K. 1999. Geologia do Quaternário e mudanças ambientais (presente+ passado= futuro?). São Paulo: Oficina de Textos. 408 p.
Suguio, K, Martin, L, Bittencourt, AC da SP. 1985. Flutuaçoes do nivel relativo do mar durante o Quaternario superior ao longo do litoral Brasileiro e suas implicaçoes na sedimentaçao costeira. Revista Brasileira de Geosciencias 15(4):273286.10.25249/0375-7536.1985273286
Taft, WH. 1967. Modern carbonate sediments. In: Developments in sedimentology. Elsevier. p. 2950.
Toby, BH, Von Dreele, RB. 2013. GSAS-II: the genesis of a modern open-source all purpose crystallography software package. J. Appl. Crystallogr. 46:544549.10.1107/S0021889813003531
Walker, RG, James, NP. 1992. Facies models. Response to sea level change. Toronto. Geosci. Canada (Reprint Ser. 1). 3rd ed. 454 p.
Xu, X, Trumbore, SE, Zheng, S, Southon, JR, McDuffee, KE, Luttgen, M, Liu, JC. 2007. Modifying a sealed tube zinc reduction method for preparation of AMS graphite targets: reducing background and attaining high precision. Nuclear Instruments and Methods in Physics Research B 259:320329.10.1016/j.nimb.2007.01.175
Yates, T. 1986. Studies of non-marine mollusks for the selection of shell samples for radiocarbon dating. Radiocarbon 28(2A):457463.10.1017/S0033822200007591


Aragonite Fraction Dating of Vermetids in the Context of Paleo Sea-Level Curves Reconstruction

  • Vinicius N Moreira (a1), Kita D Macario (a1) (a2), Renato B Guimarães (a3), Fábio F Dias (a2), Julia C Araujo (a2), Perla Jesus (a2) and Katerina Douka (a4) (a5)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.