A lake fortress, a floating chronology, and an atmospheric anomaly: the surprising results of a radiocarbon wiggle-match from Āraiši, Latvia

[1] Apals J, 1998. Āraiši (Arrasch), in Lübke C and Wędyki A, Enzyklopädie zur Geschichte des östlichen Europa (6.–13. Jahrhundert) (Encyclopedia of Eastern European History (6th–13th centuries)), Greifswald: 151–152 (in German). Search in Google Scholar

[2] Apals J, 2000. Über die Entwicklung eines Blockbautyps im Ostbaltikum (On the development of a type of log cabin in the East Baltic). Archaeologia Baltica 4: 149–158 (in German). Search in Google Scholar

[3] Apals J, 2001. Ezerpilis (Lake fortresses), in Apals J, Atgāzis M, Graudonis J, Loze I, Mugurēvičs Ē, Vasks A and Zagorska I, Latvijas senākā vēsture: 9. g. t. pr. Kr. - 1200. g. Rīga, Latvijas vēstures institūta apgāds: 311–317 (in Latvian) Search in Google Scholar

[4] Apals J, 2008. Āraišu arheoloǵiskais muzejparks: ceļvedis (Āraiši Archaeological Museum Park: Guide). Rīga, Latvijas Nacionālais vēstures muzejs: 96 pp (in Latvian). Search in Google Scholar

[5] Apals J, 2012a. Hidroarheoloǵiskās ekspedīcijas darbs 1965. gadā (Work of an archaeological expedition in 1965), in Apals J, Āraišu ezerpils. Rakstu izlase un draugu atmiņas. Rīga, Latvijas vēstures institūta apgāds: 62–65 (in Latvian). Search in Google Scholar

[6] Apals J, 2012b. Hidroarheoloǵisko pieminekļu apzināšana 1964. gadā (Exploration of underwater archaeological monuments in 1964), in Apals J, Āraišu ezerpils. Rakstu izlase un draugu atmiņas. Rīga, Latvijas vēstures institūta apgāds: 57–62 (in Latvian). Search in Google Scholar

[7] Apals J, 1983. Par Āraišu ezerpils izpēti: 1965.–1969., 1975.–1979. gads (On the investigation of the Āraiši lake fortress: 1965–1969, 1975–1979). Jaunā Gaita 145: 26–33 (in Latvian). Search in Google Scholar

[8] Bronk Ramsey C, 1995. Radiocarbon calibration and analysis of stratigraphy: The OxCal program. Radiocarbon 37: 425–430. 10.1017/S0033822200030903Search in Google Scholar

[9] Bronk Ramsey C, van der Plicht J and Weninger B, 2001. ‘Wiggle matching’ radiocarbon dates. Radiocarbon 43: 381–389. 10.1017/S0033822200038248Search in Google Scholar

[10] Bronk Ramsey C, 2009. Bayesian analysis of radiocarbon dates. Radiocarbon 51: 337–360. 10.1017/S0033822200033865Search in Google Scholar

[11] Chernyh NB, 1987. Dendrohronologicheskie shkaly Vostochnoj Evropy vtoroj poloviny 1–2 tys. n.e. (25 — letiyu laboratorii estestvennon-auchnyh metodov instituta arheologii AN SSSR) (Dendroscales of East Europe covering the second half of the 1st millennium and the 2nd millennium AD (25 years of the Natural Sciences Methods Laboratory of the Institute of Archaeology AS USSR)). In: Bitvinskas T, ed., Vremennye i prostranstvennye izmeneniya klimata i godichnye kol’tsa derev’ev, III. Kaunas, Institut botaniki AN Litovskoj SSR: 90–98 (in Russian). Search in Google Scholar

[12] Chernyh NB, 1996. Dendrohronologiya i arheologiya (Dendrochronol-ogy and Archaeology), Moscow, NOX: 215pp (in Russian). Search in Google Scholar

[13] Cook ER and Holmes RL, 1986. Users manual for program Arstan. In: Holmes R L, Adams R K and Fritts H C, eds., Tree-ring chronologies of western North America: California, eastern Oregon and northern Great Basin. Tucson, Laboratory of Tree-Ring Research, University of Arizona. Chronology Series 6: 50–65. Search in Google Scholar

[14] Crisci GM, La Russa MF, Malagodi M and Ruffolo SA, 2010. Consolidating properties of Regalrez 1126 and Paraloid B72 applied to wood. Journal of Cultural Heritage 11(3): 304–308, DOI 10.1016/j.culher.2009.12.001. http://dx.doi.org/10.1016/j.culher.2009.12.00110.1016/j.culher.2009.12.001Search in Google Scholar

[15] Grissino-Mayer HD, 2001. Evaluating crossdating accuracy: a manual and tutorial for the computer program COFECHA. Tree-Ring Research 57: 205–221. Search in Google Scholar

[16] Holmes RL, 1983. Computer-assisted quality control in tree-ring dating and measurement. Tree-Ring Bulletin 44: 69–75. Search in Google Scholar

[17] Hoper S, McCormac F, Hogg A, Higham T and Head M, 1998. Evaluation of wood pretreatments on oak and cedar. Radiocarbon 40: 45–50. 10.1017/S0033822200017860Search in Google Scholar

[18] International Study Group, 1982. An inter-laboratory comparison of radiocarbon measurements in tree-rings. Nature 298(5875): 619–623, DOI 10.1038/298619a0. http://dx.doi.org/10.1038/298619a010.1038/298619a0Search in Google Scholar

[19] McCormac FG, Bayliss A, Baillie, MGL and Brown DM, 2004. Radiocarbon calibration in the Anglo-Saxon period: AD 495-725. Radiocarbon 46: 1123–1125. 10.1017/S0033822200033051Search in Google Scholar

[20] McCormac FG, Bayliss A, Brown DM, Reimer PJ and Thompson MM, 2008. Extended radiocarbon calibration in the Anglo-Saxon period, AD 395-485 and AD 735-805. Radiocarbon 50: 11–17. 10.1017/S0033822200043344Search in Google Scholar

[21] Miyake F, Nagaya K, Masuda K and Nakamura T, 2012. A signature of cosmic-ray increase in AD 774-775 from tree rings in Japan. Nature 486(7402): 240–242, DOI 10.1038/nature11123. Search in Google Scholar

[22] Nadeau M-J, Grootes PM, Schleicher M, Hasselberg P, Rieck A and Bitterling M, 1998. Sample throughput and data quality at the Leibniz-Labor AMS facility. Radiocarbon 40: 239–245. 10.1017/S0033822200018105Search in Google Scholar

[23] Punning JM, Liiva A and Ilves E, 1968. Tartu radiocarbon dates III. Radiocarbon 10: 379–383. 10.1017/S0033822200010973Search in Google Scholar

[24] 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 TJ, Hogg AG, Hughen KA, Kaiser KF, Kromer B, McCormac G, Manning S, Reimer RW, Remmele S, Richards DA, Southon JR, Talamo S, Taylor FW, Turney CSM, van der Plicht J and Weyhenmeyer CE, 2009. INTCAL09 and MARINE09 radiocarbon age calibration curves, 0-50,000 years cal BP. Radiocarbon 51: 1111–1150. 10.1017/S0033822200034202Search in Google Scholar

[25] Reimer PJ, Bard E, Bayliss A, Beck JW, Blackwell PG, Bronk Ramsey C, Grootes PM, Guilderson TP, Haflidason H, Hajdas I, Hatte C, Heaton TJ, Hoffmann DL, Hogg AG, Hughen KA, Kaiser KF, Kromer B, Manning SW, Niu M, Reimer RW, Richards DA, Scott EM, Southon JR, Staff RA, Turney CSM and van der Plicht J, 2013. IntCal13 and Marine13 radiocarbon age calibration curves 0-50,000 years cal BP. Radiocarbon 55: 1869–1887. http://dx.doi.org/10.2458/azu_js_rc.55.1694710.2458/azu_js_rc.55.16947Search in Google Scholar

[26] Stuiver M, Reimer PJ, Bard E, Beck JW, Burr GS, Hughen KA, Kromer B, McCormac G, van der Plicht J and Spurk M, 1998. INTCAL98 radiocarbon age calibration, 24,000-0 cal BP. Radiocarbon 40: 1041–1083. 10.1017/S0033822200019123Search in Google Scholar

[27] Tyers C, Sidell J, van der Plicht J, Marshall P, Cook G, Bronk Ramsey C and Bayliss A, 2011. Wiggle-matching using known-age pine from Jermyn Street, London. Radiocarbon 51: 385–396. 10.1017/S0033822200055788Search in Google Scholar

[28] Usoskin IG, Kromer B, Ludlow F, Beer J, Friedrich M, Kovaltsov GA, Solanki SK and Wacker L, 2013. The AD775 cosmic event revisited: the Sun is to blame. Astronomy & Astrophysics 552: L3, DOI 10.1051/0004-6361/201321080. http://dx.doi.org/10.1051/0004-6361/20132108010.1051/0004-6361/201321080Search in Google Scholar

[29] Ward GK and Wilson SR, 1978. Procedures for comparing and combining radiocarbon age determinations: a critique. Archaeometry 20(1): 19–31, DOI 10.1111/j.1475-4754.1978.tb00208.x. http://dx.doi.org/10.1111/j.1475-4754.1978.tb00208.x10.1111/j.1475-4754.1978.tb00208.xSearch in Google Scholar

[30] Zaitseva GI and Popov SG, 1994. Radiocarbon dating sites of northwest Russia and Latvia. Radiocarbon 36: 377–389. 10.1017/S0033822200014557Search in Google Scholar

[31] Zunde M, 2000. Par Āraišu ezerpils dendrohronoloǵisko datēšanu (On the dendrochronological dating of Āraiši lake fortress). In: Arheologs Dr. hist., Dr. hist. h.c. Jānis Apals: Bibliogrāfija, darbabiedru veltījumi 70 gadu jubilejā. Rīga, Latvijas vēstures institūta apgāds: 144–157 (in Latvian). Search in Google Scholar