Hostname: page-component-5d59c44645-n6p7q Total loading time: 0 Render date: 2024-02-25T18:30:06.728Z Has data issue: false hasContentIssue false

IntCal, SHCal, or a Mixed Curve? Choosing a 14C Calibration Curve for Archaeological and Paleoenvironmental Records from Tropical South America

Published online by Cambridge University Press:  16 March 2018

Erik J Marsh*
CONICET, Laboratorio de Paleo-Ecología Humana, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, 5500, Argentina
Maria C Bruno
Dickinson College, Department of Anthropology & Archaeology, PO Box 1773, Carlisle, PA 17013, USA
Sherilyn C Fritz
Department of Earth and Atmospheric Sciences and School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68588-0340, USA; and Department of Geology, Lund University, Lund SE-223 62, Sweden
Paul Baker
Division of Earth and Ocean Sciences, Duke University, Durham, NC 27708, USA
José M Capriles
Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA
Christine A Hastorf
Department of Anthropology, University of California, Berkeley, 232 Kroeber Hall, Berkeley, CA 94720, USA
*Corresponding author. Email:


Because the 14C calibration curves IntCal and SHCal are based on data from temperate latitudes, it remains unclear which curve is more suitable for archaeological and paleoenvironmental records from tropical South America. A review of climate dynamics reveals a significant influx of Northern Hemisphere air masses and moisture over a substantial part of the continent during the South American Summer Monsoon (SASM). Areas affected by the SASM receive unknown amounts of input from both hemispheres, where an argument could be made for either curve. Until localized tree-ring data can resolve this, we suggest using a mixed calibration curve, which accounts for inputs from both hemispheres, as a third calibration option. We present a calibration example from a crucial period of environmental and cultural change in the southern Lake Titicaca. Given our current lack of data on past ∆14C variation in South America, our calibrations and chronologies will likely change in the future. We hope this paper spurs new research into this topic and encourages researchers to make an informed and explicit choice of which curve to use, which is particularly relevant in research on past human–environmental relationships.

Research Article
© 2018 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)



Abbott, MB, Binford, MW, Brenner, M, Kelts, KR. 1997. A 3500 14C yr high-resolution record of water-level changes in Lake Titicaca, Bolivia/Peru. Quaternary Research 47(2):169180.CrossRefGoogle Scholar
Anderson, RF, Ali, S, Bradtmiller, LI, Nielsen, SHH, Fleisher, MQ, Anderson, BE, Burckle, LH. 2009. Wind-driven upwelling in the southern ocean and the deglacial rise in atmospheric CO2 . Science 323(5920):14431448.CrossRefGoogle ScholarPubMed
Andreu-Hayles, L, Santos, G, Herrera-Ramírez, D, Martin-Fernández, J, Ruiz-Carrascal, D, Boza-Espinoza, T, Fuentes, A, Jørgensen, P. 2015. Matching dendrochronological dates with the southern hemisphere 14C bomb curve to confirm annual tree rings in Pseudolmedia Rigida from Bolivia. Radiocarbon 57(1):113.CrossRefGoogle Scholar
Baker, PA, Fritz, SC. 2015. Nature and causes of quaternary climate variation of tropical South America. Quaternary Science Reviews 124:3147.CrossRefGoogle Scholar
Binford, MW, Kolata, AL, Brenner, M, Janusek, JW, Seddon, MT, Abbott, M, Curtis, JH. 1997. Climate variation and the rise and fall of an Andean civilization. Quaternary Research 47:235248.Google Scholar
Braziunas, TF, Fung, IY, Stuiver, M. 1995. The preindustrial atmospheric 14CO2 latitudinal gradient as related to exchanges among atmospheric, oceanic, and terrestrial reservoirs. Global Biogeochemical Cycles 9(4):565584.Google Scholar
Bronk Ramsey, C. 2001. Development of the radiocarbon calibration program. Radiocarbon 43(2A):355363.CrossRefGoogle Scholar
Bronk Ramsey, CB. 2009. Bayesian analysis of radiocarbon dates. Radiocarbon 51(1):337360.Google Scholar
Bronk Ramsey, C, Lee, S. 2013. Recent and planned developments of the program OxCal. Radiocarbon 55(2–3):720730.Google Scholar
Browman, DL. 1981. New light on Andean Tiwanaku. American Scientist 69:408419.Google Scholar
Bruno, MC, Whitehead, W. 2003. Chenopodium cultivation and Formative period agriculture at Chiripa, Bolivia. Latin American Antiquity 14(3):339356.Google Scholar
Buck, CE. 2004. Bayesian chronological data interpretation: Where now? In: Buck CE, Millard A, editors. Tools for Constructing Chronologies. London: Springer. p 124.CrossRefGoogle Scholar
Capriles, JM, Albarracín-Jordan, J. 2013. The earliest human occupations in Bolivia: a review of the archaeological evidence. Quaternary International 301:4659.Google Scholar
Capriles, JM, Moore, KM, Domic, AI, Hastorf, CA. 2014. Fishing and environmental change during the emergence of social complexity in the Lake Titicaca Basin. Journal of Anthropological Archaeology 34:6677.Google Scholar
Chiang, JCH, Bitz, CM. 2005. Influence of high latitude ice cover on the marine Intertropical Convergence Zone. Climate Dynamics 25(5):477496.Google Scholar
Cook, KH. 2009. South American climate variability and change: remote and regional forcing processes. In: Vimeux F, Sylvestre F, Khodri, editors. Past climate variability in South America and surrounding regions. New York: Springer. p 193212.Google Scholar
Contreras, DA. 2017. Correlation is not enough–building better arguments in the archaeology of human-environment interactions. In: Contreras DA, editor. The archaeology of Human–Environment Interactions: Strategies for Investigating Anthropogenic Landscapes, Dynamic Environments, and Climate Change in the Human Past. New York: Routledge. p 322.Google Scholar
Cross, S, Baker, PA, Seltzer, GO, Fritz, SC, Dunbar, RB. 2000. A new estimate of the Holocene lowstand level of Lake Titicaca, central Andes, and implications for tropical paleohydrology. The Holocene 10(1):2132.Google Scholar
Curtis, S, Hastenrath, S. 1999. Trends of upper-air circulation and water vapour over equatorial South America and adjacent oceans. International Journal of Climatology 19:863876.3.0.CO;2-2>CrossRefGoogle Scholar
Dutta, K. 2016. Sun, ocean, nuclear bombs, and fossil fuels: radiocarbon variations and implications for high-resolution dating. Annual Review of Earth and Planetary Sciences 44(1):239275.Google Scholar
Engel, Z, Skrzypek, G, Chuman, T, Šefrna, L, Mihaljevič, M. 2014. Climate in the western cordillera of the central Andes over the last 4300 years. Quaternary Science Reviews 99:6077.Google Scholar
Finucane, BC, Valdez, JE, Pérez Calderon, I, Vivanco Pomacanchari, C, Valdez, LM, O’Connell, T. 2007. The end of empire: new radiocarbon dates from the Ayacucho Valley, Peru, and their implications for the collapse of the Wari state. Radiocarbon 49(2):579592.CrossRefGoogle Scholar
Franke, J, Paul, A, Schulz, M. 2008. Modeling variations of marine reservoir ages during the last 45 000 years. Climate of the Past Discussions 4(1):81110.Google Scholar
Garreaud, RD. 2009. The Andes climate and weather. Advances in Geosciences 22:311.Google Scholar
Garreaud, RD, Vuille, M, Compagnucci, R, Marengo, J. 2009. Present-day South American climate. Palaeogeography, Palaeoclimatology, Palaeoecology 281:180195.Google Scholar
Gayo, EM, Lattorre, C, Maldonado, A, DePol-Holz, R. 2012. Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 yr. Climate of the Past 8:287306.Google Scholar
Hastenrath, S, Heller, L. 1977. Dynamics of climatic hazards in northeast brazil. Quarterly Journal of the Royal Meteorological Society 103(435):7792.Google Scholar
Haug, GH, Hughen, KA, Sigman, DM, Peterson, LC, Röhl, U. 2001. Southward migration of the Intertropical Convergence Zone through the Holocene. Science 293(5533):13041308.Google Scholar
Hogg, AG, Bronk Ramsey, CB, Turney, C, Palmer, J. 2009. Bayesian evaluation of the Southern Hemisphere radiocarbon offset during the Holocene. Radiocarbon 51(4):11651176.Google Scholar
Hogg, A, Palmer, J, Boswijk, G, Reimer, P, Brown, D. 2011. Investigating the interhemispheric 14C offset in the 1st millennium AD and assessment of laboratory bias and calibration errors. Radiocarbon 51(4):11771186.CrossRefGoogle Scholar
Hogg, AG, Hua, Q, Blackwell, PG, Niu, M, Buck, CE, Guilderson, TP, Heaton, TJ, Palmer, JG, Reimer, PJ, Reimer, RW. 2013a. SHCal13 Southern Hemisphere calibration, 0–50,000 cal yr BP. Radiocarbon 55(2):18891903.Google Scholar
Hogg, A, Turney, C, Palmer, J, Cook, E, Buckley, B. 2013b. Is there any evidence for regional atmospheric 14C offsets in the Southern Hemisphere? Radiocarbon 55(4):20292034.Google Scholar
Hua, Q, Barbetti, M, Zoppi, U. 2004a. Radiocarbon in annual tree rings from Thailand during the pre-bomb period, AD 1938–1954. Radiocarbon 46(2):925932.CrossRefGoogle Scholar
Hua, Q, Barbetti, M, Zoppi, U, Fink, D, Watanasak, M, Jacobsen, GE. 2004b. Radiocarbon in tropical tree rings during the Little Ice Age. Nuclear Instruments and Methods in Physics Research B 223:489494.Google Scholar
Hua, Q, Barbetti, M. 2007. Influence of atmospheric circulation on regional 14CO2 differences. Journal of Geophysical Research 112:D1902.CrossRefGoogle Scholar
Hua, Q, Barbetti, M, Rakowski, AZ. 2013. Atmospheric radiocarbon for the period 1950–2010. Radiocarbon 55(4):20592072.Google Scholar
Insel, N, Poulsen, CJ, Sturm, C, Ehlers, TA. 2013. Climate controls on Andean precipitation δ18O interannual variability. Journal of Geophysical Research: Atmospheres 118(17):97219742.Google Scholar
Jenkins, HS. 2009. Amazon Climate Reconstruction Using Growth Rates and Stable Isotopes of Tree Ring Cellulose from the Madre de Dios Basin, Peru [PhD dissertation]. Durham, NC: Department of Earth & Ocean Sciences, Duke University.Google Scholar
Jenkins, HS, Baker, PA, Negrón-Juárez, RI. 2013. Eventos extremos de seca na Amazonia revelados pelos registros de aneis de arvores. In: Borma L, Nobre C, editors. Secas na Amazonia. Sao Paulo: Editora Oficina de Testos. p 2946.Google Scholar
Jones, C, Carvalho, LMV. 2013. Climate change in the South American monsoon system: present climate and CMIP5 projections. Journal of Climate 26(17):66606678.CrossRefGoogle Scholar
Jones, KB, Hodgins, GWL, Sandweiss, DH. 2017. Radiocarbon chronometry of site QJ-280, Quebrada Jaguay, a Terminal Pleistocene to early Holocene fishing site in southern Peru. The Journal of Island and Coastal Archaeology. In press.CrossRefGoogle Scholar
Kitagawa, H, Mukai, H, Nojiri, Y, Shibata, Y, Kobayashi, T, Nojiri, T. 2004. Seasonal and secular variations of atmospheric 14CO2 over the western Pacific since 1994. Radiocarbon 46(2):901910.Google Scholar
Koons, ML, Alex, BA. 2014. Revised Moche chronology based on Bayesian models of reliable radiocarbon dates. Radiocarbon 56(3):10391055.Google Scholar
Krakauer, NY, Randerson, JT, Primeau, FW, Gruber, N, Menemenlis, D. 2006. Carbon isotope evidence for the latitudinal distribution and wind speed dependence of the air–sea gas transfer velocity. Tellus B: Chemical and Physical Meteorology 58(5):390417.CrossRefGoogle Scholar
Lerman, JC, Mook, WG, Vogel, JC. 1970. C14 in tree rings from different localities. In: Olsson IU, editor. Radiocarbon Variations and Absolute Chronology, Proceedings, XII Nobel Symposium. Hoboken, NJ: John Wiley. p 275–301.Google Scholar
Levin, I, Kromer, B, Wagenbach, DT, Münnich, KO. 1987. Carbon isotope measurements of atmospheric CO2 at a coastal station in Antarctica. Tellus B: Chemical and Physical Meteorology 39(1–2):8995.Google Scholar
Levine, A, Stanish, C. 2013. The importance of multiple 14C dates from significant archaeological contexts. Journal of Archaeological Method and Theory 21:824836.Google Scholar
McCormac, FG, Hogg, AG, Higham, TFG, Lynch-Stieglitz, J, Broecker, WS, Baillie, MGL, Palmer, J, Xiong, L, Pilcher, JR, Brown, D. 1998. Temporal variation in the interhemispheric 14C offset. Geophysical Research Letters 25(9):13211324.CrossRefGoogle Scholar
McCormac, FG, Reimer, PJ, Hogg, AG, Higham, TFG, Baillie, MGL, Palmer, J, Stuiver, M. 2002. Calibration of the radiocarbon time scale for the southern hemisphere: AD 1850–950. Radiocarbon 44(3):641651.Google Scholar
McCormac, FG, Hogg, AG, Blackwell, PG, Buck, CE, Higham, TFG, Reimer, PJ. 2004. SHCal04 southern hemisphere calibration, 0–11.0 cal kyr BP. Radiocarbon 46(3):10871092.Google Scholar
Marsh, EJ. 2012. A Bayesian re-assessment of the earliest radiocarbon dates from Tiwanaku, Bolivia. Radiocarbon 54(2):203218.Google Scholar
Marsh, EJ. 2015. The emergence of agropastoralism: Accelerated ecocultural change on the Andean altiplano, ~3540–3120 cal BP. Environmental Archaeology 20(1):1329.CrossRefGoogle Scholar
Marsh, EJ. 2016. The disappearing desert and the emergence of agropastoralism: An adaptive cycle of rapid change in the mid-Holocene Lake Titicaca Basin (Peru–Bolivia). Quaternary International 422:123134.Google Scholar
Marsh, EJ, Kidd, R, Ogburn, D, Durán, V. 2017. Dating the expansion of the Inca empire:Bayesian models from Ecuador and Argentina. Radiocarbon 59(1):117140.Google Scholar
Martel-Cea, A, Maldonado, A, Grosjean, M, Alvial, I, de Jong, R, Fritz, SC, von Gunten, L. 2016. Late Holocene environmental changes as recorded in the sediments of high Andean Laguna Chepical, central Chile (32°S; 3050 m a.s.l.). Palaeogeography, Palaeoclimatology, Palaeoecology 461:4454.Google Scholar
Millard, A. 2014. Conventions for reporting radiocarbon determinations. Radiocarbon 56(2):555559.Google Scholar
Morales, MS, Christie, DA, Villalba, R, Argollo, J, Pacajes, J, Silva, JS, Alvarez, CA, Llancabure, JC, Gamboa Soliz, CC. 2012. Precipitation changes in the South American altiplano since 1300 AD reconstructed by tree-rings. Climate of the Past 8(2):653666.Google Scholar
Morales, MS, Nielsen, AE, Villalba, R. 2013. First dendroarchaeological dates of prehistoric contexts in South America:Chullpas in the central Andes. Journal of Archaeological Science 40(5):23932401.Google Scholar
Mourguiart, P, Corrège, T, Wirrmann, D, Argollo, J, Montenegro, ME, Pourchet, M, Carbonel, P. 1998. Holocene palaeohydrology of Lake Titicaca estimated from an ostracod-based transfer function. Palaeogeography, Palaeoclimatology, Palaeoecology 143(1):5172.Google Scholar
Nace, TE, Baker, PA, Dwyer, GS, Silva, CG, Rigsby, CA, Burns, SJ, Giosan, L, Otto-Bliesner, B, Liu, Z, Zhu, J. 2014. The role of north Brazil current transport in the paleoclimate of the Brazilian nordeste margin and paleoceanography of the western tropical Atlantic during the late Quaternary. Palaeogeography, Palaeoclimatology, Palaeoecology 415:313.Google Scholar
Nelson, DB, Sachs, JP. 2016. Galapagos hydroclimate of the Common Erafrom paired microalgal and mangrove biomarker 2H/1H values. PNAS 113:34763481.Google Scholar
Ogburn, DE. 2012. Reconceiving the chronology of Inca imperial expansion. Radiocarbon 54(2):219237.Google Scholar
Poveda, G, Waylen, PR, Pulwarty, RS. 2006. Annual and inter-annual variability of the present climate in northern South America and southern Mesoamerica. Palaeogeography, Palaeoclimatology, Palaeoecology 234(1):327.Google Scholar
Reimer, PJ, Baillie, MG, Bard, E, Bayliss, A, Beck, JW, Bertrand, CJ, Blackwell, PG, Buck, CE, Burr, GS, Cutler, KB, Damon, PE, Edwards, RL, Fairbanks, RG, Friedrich, M, Guilderson, TP, Hogg, AG, Hughen, KA, Kromer, B, McCormac, G, Manning, S, Bronk Ramsey, CB, Reimer, RW, Remmele, S, Southon, JR, Stuiver, M, Talamo, S, Taylor, FW, van der Plicht, J, Weyhenmeyer, CE. 2004. IntCal04 terrestrial radiocarbon age calibration, 0–26 cal kyr BP. Radiocarbon 46(3):10291058.Google Scholar
Reimer, PJ, Bard, E, Bayliss, A, Beck, JW, Blackwell, PG, Ramsey, CB, Grootes, PM, Guilderson, TP, Haflidason, H, Hajdas, I, Hatté, C, Heaton, TJ, Hoffma, DL, Hogg, AG, Hughen, KA, Kaiser, KF, Kromer, B, Manning, S, 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
Rick, JW, Mesia, C, Contreras, D, Rodriguez Kembel, S, Rick, R, Sayre, M, Wolf, J. 2009. La cronología de Chavín de Huántar y sus implicancias para el Periodo Formativo. Boletín de Arqueología PUCP 13:87132.Google Scholar
Rigsby, CA, Baker, PA, Aldenderfer, MS. 2003. Fluvial history of the Rio Ilave Valley, Peru, and its relationship to climate and human history. Palaeogeography, Palaeoclimatology, Palaeoecology 194(1):165185.Google Scholar
Rodgers, B, Mikaloff-Fletcher, E, Bianchi, D, Beaulieu, C, Galbraith, D, Gnanadesikan, A, Hogg, G, Iudicone, D, Lintner, R, Naegler, T, Reimer, J, Sarmiento, L, Slater, D. 2011. Interhemispheric gradient of atmospheric radiocarbon reveals natural variability of southern ocean winds. Climate of the Past 7(4):11231138.Google Scholar
Roth, R, Joos, F. 2013. A reconstruction of radiocarbon production and total solar irradiance from the Holocene 14C and CO2 records: implications of data and model uncertainties. Climate of the Past 9(4):18791909.Google Scholar
Rozanski, K, Levin, I, Stock, J, Falcon, REG, Rubio, F. 1995. Atmospheric 14CO2 variations in the equatorial region. Radiocarbon 37(2):509515.Google Scholar
Sachs, JP, Sachse, D, Smittenberg, RH, Zhang, Z, Battisti, DS, Golubic, S. 2009. Southward movement of the Pacific Intertropical Convergence Zone AD 1400–1850. Nature Geoscience 2(7):519525.CrossRefGoogle Scholar
Santos, GM, Linares, R, Lisi, CS, Tomazello Filho, M. 2015. Annual growth rings in a sample of Paraná pine (Araucaria Angustifolia): toward improving the 14C calibration curve for the Southern Hemisphere. Quaternary Geochronology 25:96103.Google Scholar
Schneider, T, Bischoff, T, Haug, GH. 2014. Migrations and dynamics of the Intertropical Convergence Zone. Science 513:4553.Google Scholar
Seltzer, GO, Baker, PA, Cross, SL, Dunbar, RB, Fritz, SC. 1998. High-resolution seismic reflection profiles from Lake Titicaca, Peru-Bolivia: evidence for Holocene aridity in the tropical Andes. Geology 26(2):167170.Google Scholar
Stuiver, M, Braziunas, TF. 1993. Sun, ocean, climate and atmospheric 14CO2: an evaluation of causal and spectral relationships. The Holocene 3(4):289305.Google Scholar
Stuiver, M, Braziunas, TF. 1998. Anthropogenic and solar components of hemispheric 14C. Geophysical Research Letters 25(3):329332.Google Scholar
Sturm, C, Hoffmann, G, Langmann, B. 2007. Simulation of the stable water isotopes in precipitation over South America: comparing regional to global circulation models. Journal of Climate 20(15):37303750.Google Scholar
Suzuki, K, Sakurai, H, Takahashi, Y, Sato, T, Gunji, S, Tokanai, F, Matsuzaki, H, Tsuchiya, YS. 2010. Precise comparison of 14C ages from Choukai Jindai cedar with IntCal04 raw data. Radiocarbon 52(4):15991609.Google Scholar
Tapia, PM, Fritz, SC, Baker, PA, Seltzer, GO, Dunbar, RB. 2003. A late Quaternary diatom record of tropical climatic history from Lake Titicaca(Peru and Bolivia). Palaeogeography, Palaeoclimatology, Palaeoecology 194:139164.Google Scholar
Turnbull, JC, Graven, H, Krakauer, NY. 2016. Radiocarbon in the atmosphere. In: Schuur EAG, Druffel ERM, Trumbore SE, editors. Radiocarbon and Climate Change. New York: Springer. p 83137.Google Scholar
Turney, CS, Palmer, J, Hogg, A, Fogwill, CJ, Jones, R, Ramsey, CB, Fenwick, P, Grierson, P, Wilmshurst, J, O’Donnell, A, Thomas, Z, Lipson, M. 2016. Multi-decadal variations in Southern Hemisphere atmospheric 14C: evidence against a southern ocean sink at the end of the Little Ice Age CO2 anomaly. Global Biogeochem. Cycles 30:211218.Google Scholar
Turney, CS, Palmer, JG. 2007. Does the El Niño–Southern Oscillation control the interhemispheric radiocarbon offset? Quaternary Research 67(1):174180.Google Scholar
Vogel, JC, Fuls, A, Visser, E, Becker, B. 1993. Pretoria calibration curve for short-lived samples, 1930–3350 BC. Radiocarbon 35(1):7385.Google Scholar
Vuille, M, Burns, SJ, Taylor, BL, Cruz, FW, Bird, BW, Abbott, MB, Kanner, LC, Cheng, H, Novello, VF. 2012. A review of the South American monsoon history as recorded in stable isotopic proxies over the past two millennia. Climate of the Past 8(4):13091321.Google Scholar
Vimeux, F, Gallaire, R, Bony, S, Hoffmann, G, Chiang, JC. 2005. What are the climate controls on δD in precipitation in the Zongo Valley (Bolivia)? Implications for the Illimani ice core interpretation. Earth and Planetary Science Letters 240(2):205220.Google Scholar
Weide, DM, Fritz, SC, Hastorf, CA, Bruno, MC, Baker, PA, Guedron, S, Salenbien, W. 2017. A ~6000 yr diatom record of mid- to late Holocene fluctuations in the level of Lago Wiñaymarca, Lake Titicaca (Peru/Bolivia). Quaternary Research. In press.Google Scholar
Whitehead, WT. 1999. Radiocarbon dating. In: Hastorf, editor. Early settlement at Chiripa, Bolivia:Research of the Taraco Archaeological Project. Contributions of the Archaeological Research Facility. Vol. 57. Berkeley, CA: University of California. p 1722.Google Scholar
Xie, P, Arkin, PA. 1997. Global precipitation: a 17-year monthly analysis based on gauge observations, satellite estimates, and numerical model outputs. Bulletin of the American Meteorological Society 78:25392558.Google Scholar