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Changes of Chemical Structure and Composition of Charcoal by Radiocarbon Pretreatments: Decontamination by ABA and ABOx Treatments

Published online by Cambridge University Press:  11 May 2016

Shinji Tomiyama
Affiliation:
Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan.
Masayo Minami*
Affiliation:
Institute for Space-Earth Environmental Research, Nagoya University, Nagoya 464-8601, Japan.
Toshio Nakamura
Affiliation:
Institute for Space-Earth Environmental Research, Nagoya University, Nagoya 464-8601, Japan.
Koichi Mimura
Affiliation:
Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan.
Hiroyuki Kagi
Affiliation:
Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
*
*Corresponding author. Email: [email protected].

Abstract

Charcoal is widely used for radiocarbon dating in archaeological and paleoenvironmental studies. Reliable 14C dating requires appropriate chemical treatment to remove postdeposition contamination from the charcoal samples. This study assesses two pretreatments: acid-base-acid (ABA) and acid-base-oxidation with stepped combustion (ABOx-SC). In addition to 14C, the effects of the treatments on the chemical structure and composition of charcoal were studied using Fourier transform infrared spectroscopy (FTIR) and C/H/O elemental analysis. Samples of pine wood charred in the laboratory at 270, 300, 400, 500, and 600°C, and environmental samples of charred pine wood from pyroclastic flow deposits in southern Kyushu, Japan, were tested. The laboratory-charred samples showed that NaOH treatment removed highly hydrophilic organic components derived from endogenous and exogenous organic materials in the samples and that oxidation treatment caused the oxidative degradation of molecules in samples starting from its edges. The ABA-treated environmental charcoal yielded younger 14C dates than the ABOx-treated samples, probably owing to the effects of remaining organic contaminants bound to the edges of the aromatic molecular structures produced by the original pyrolysis. Meanwhile, it was found that ABA-SC treatment can reduce contaminants as effectively as ABOx-SC treatment. This implies that the stepped combustion (SC), not the chemical oxidation, is the key to reduce contaminant residue left after ABA and ABOx treatments. The results in this study indicate that the investigation of the structural and compositional changes of charcoal during its pretreatment is useful for assessment of the reliability of the 14C ages.

Type
Research Article
Copyright
© 2016 by the Arizona Board of Regents on behalf of the University of Arizona 

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References

REFERENCES

Alon, D, Mintz, G, Cohen, I, Weiner, S, Boaretto, E. 2002. The use of Raman spectroscopy to monitor the removal of humic substances from charcoal: quality control for 14C dating of charcoal. Radiocarbon 44(1):111.Google Scholar
Ascough, PL, Bird, MI, Scott, AC, Collinson, ME, Cohen-Ofri, I, Snape, CE, Le Manquais, K. 2010. Charcoal reflectance measurements: implications for structural characterization and assessment of diagenetic alteration. Journal of Archaeological Science 37(7):15901599.CrossRefGoogle Scholar
Ascough, PL, Bird, MI, Francis, SM, Lebl, T. 2011. Alkali extraction of environmental charcoal: evidence for diagenetic degradation and formation of humic acids. Journal of Archaeological Science 38(1):6978.Google Scholar
Bird, MI, Ascough, PL. 2012. Isotopes in pyrogenic carbon: a review. Organic Geochemistry 42(12):15291539.Google Scholar
Bird, MI, Ayliffe, LK, Fifield, LK, Turney, CSM, Cresswell, RG, Barrows, TT, David, B. 1999. Radiocarbon dating of “old” charcoal using a wet oxidation, stepped-combustion procedure. Radiocarbon 41(2):127140.Google Scholar
Bird, MI, Turney, CSM, Fifield, LK, Jones, R, Ayliffe, LK, Palmer, A, Cresswell, R, Robertson, S. 2002. Radiocarbon analysis of the early archaeological site of Nauwalabila I, Arnhem Land, Australia: implications for sample suitability and stratigraphic integrity. Quaternary Science Reviews 21(8–9):10611075.Google Scholar
Bird, MI, Levchenko, V, Ascough, PL, Meredith, W, Wurster, CM, Williams, A, Tilston, EL, Snape, CE, Apperley, DC. 2014. The efficiency of charcoal decontamination for radiocarbon dating by three pre-treatments- ABOX, ABA and hypy. Quaternary Geochronology 22:2532.Google Scholar
Braadbaart, F, Poole, I. 2008. Morphological, chemical and physical changes during charcoalification of wood and its relevance to archaeological contexts. Journal of Archaeological Science 35(9):24342445.Google Scholar
Braadbaart, F, Poole, I, van Brussel, AA. 2009. Preservation potential of charcoal in alkaline environments: an experimental approach and implications for the archaeological record. Journal of Archaeological Science 36(8):16721679.Google Scholar
Brock, F, Higham, TFG. 2009. AMS radiocarbon dating of Paleolithic-aged charcoal from Europe and the Mediterranean Rim using ABOx-SC. Radiocarbon 51(2):839846.Google Scholar
Brock, F, Higham, TFG, Ditchfield, P, Bronk Ramsey, C. 2010. Current pretreatment methods for AMS radiocarbon dating at the Oxford Radiocarbon Accelerator Unit (ORAU). Radiocarbon 52(1):103112.Google Scholar
Bronk Ramsey, C. 2009. Bayesian analysis of radiocarbon dates. Radiocarbon 51(1):337360.Google Scholar
Cohen-Ofri, I, Weiner, L, Boaretto, E, Mintz, G, Weiner, S. 2006. Modern and fossil charcoal: aspects of structure and diagenesis. Journal of Archaeological Science 33(3):428439.Google Scholar
Douka, K, Higham, T, Sinitsyn, A. 2010. The influence of pre-treatment chemistry on the radiocarbon dating of Campanian ignimbrite-aged charcoal from Kostenki 14 (Russia). Quaternary Research 73(3):10211027.Google Scholar
Franklin, RE. 1951. Crystallite growth in graphitizing and non-graphitizing carbons. Proceedings of the Royal Society A 209:196218.Google Scholar
Hammes, K, Smernik, RJ, Skjemstad, JO, Herzog, A, Vogt, UF, Schmidt, MWI. 2006. Synthesis and characterization of laboratory-charred grass straw (Oryza sativa) and chestnut wood (Castanea sativa) as reference materials for black carbon quantification. Organic Geochemistry 37:16291633.Google Scholar
Higham, T, Brock, F, Peresani, M, Broglio, A, Wood, R, Douka, K. 2009. Problems with radiocarbon dating the Middle to Upper Palaeolithic transition in Italy. Quaternary Science Reviews 28(13–14):12571267.Google Scholar
Ishimaru, K, Hata, T, Bronsveld, P, Meier, D, Imamura, Y. 2007. Spectroscopic analysis of carbonization behavior of wood, cellulose and lignin. Journal of Materials Science 42(1):122129.CrossRefGoogle Scholar
Kuriyama, A. 1979. A study on the carbonization process of wood. Bulletin of the Forestry and Forest Products Research Institute 304:776.Google Scholar
Matsumoto, T, Uto, K, Ono, K, Watanabe, K. 1991. K-Ar age determinations for Aso volcanic rocks: concordance with volcanostratigraphy and application flow. In: Proceedings of the Fall Meeting of the Volcanological Society, Japan. p 73. In Japanese.Google Scholar
Olson, EA, Broecker, WS. 1958. Sample contamination and reliability of radiocarbon dates. Transactions of the New York Academy of Science Series II 20:593604.CrossRefGoogle Scholar
Preston, CM, Schmidt, MWI. 2006. Black (pyrogenic) carbon: a synthesis of current knowledge and uncertainties with special consideration of boreal regions. Biogeosciences 3:397420.Google Scholar
Rebollo, NR, Cohen-Ofri, I, Popovitz-Biro, R, Bar-Yosef, O, Meignen, L, Goldberg, P, Weiner, S, Boaretto, E. 2008. Structural characterization of charcoal exposed to high and low pH: implication for 14C sample preparation and charcoal preservation. Radiocarbon 50(2):289307.Google Scholar
Rebollo, NR, Weiner, S, Brock, F, Meignen, L, Goldberg, P, Belfer-Cohen, A, Bar-Yosef, O, Boaretto, E. 2011. New radiocarbon dating of the transition from Middle to the Upper Paleolithic in Kebara Cave, Israel. Journal of Archaeological Science 38(9):24242433.Google Scholar
Reimer, PJ, Bard, E, Bayliss, A, Beck, JW, Blackwell, PG, Bronk Ramsey, C, Buck, CE, Cheng, H, Edwards, RL, Friedrich, M, Grootes, PM, Guilderson, TP, Hajdas, I, Hatté, C, Heaton, TJ, Hoffmannm, DI, Hogg, AG, Hughen, KA, Kaiser, KF, Kromer, B, Manning, SW, Niu, M, Reimer, RW, Richards, DA, Scott, EM, Southon, JR, Staff, RA, Turney, CSM, van der Plicht, J. 2013. IntCal13 and Marine13 radiocarbon age calibration curves, 0–50,000 years cal BP. Radiocarbon 55(4):18691887.Google Scholar
Styring, AK, Manning, H, Fraser, RA, Wallace, M, Jones, G, Charles, M, Heaton, THE, Bogaard, A, Evershed, RP. 2013. The effect of charring and burial on the biochemical composition of cereal grains: investigating the integrity of archaeological plant material. Journal of Archaeological Science 40(12):47674779.CrossRefGoogle Scholar
Swift, LW, Elliott, KJ, Ottmar, RD, Vihnanek, RE. 1993. Site preparation burning to improve southern Appalachian pine-hardwood stands: fire characteristics and soil erosion, moisture, and temperature. Canadian Journal of Forest Research 23:22422254.Google Scholar
Turney, CSM, Bird, MI, Fifield, LK, Roberts, RG, Smith, M, Dortch, CE, Grün, R, Lawson, E, Ayliffe, LK, Miller, GH, Dortch, J, Cresswell, RG. 2001. Early human occupation at Devil’s Lair, southwestern Australia 50,000 years ago. Quaternary Research 55(1):313.Google Scholar
Vandeputte, K, Moen, L, Dams, R. 1998. Study of the 14C-contamination potential of C-impurities in CuO and Fe. Radiocarbon 40(1):103110.Google Scholar
Wood, RE, Douka, K, Boscato, P, Haesaerts, P, Sintisyn, A, Higham, TFG. 2012. Testing the ABOx-SC method: dating known-age charcoals associated with the Campanian Ignimbrite. Quaternary Geochronology 9:1621.Google Scholar
Yizhaq, M, Mintz, G, Cohen, I, Khalaily, H, Weiner, S, Boaretto, E. 2005. Quality controlled radiocarbon dating of bones and charcoal from the early pre-Pottery Neolithic B (PPNB) of Motza (Israel). Radiocarbon 47(2):193206.Google Scholar