Radiocarbon-based approach capable of subannual precision resolves the origins of the site of Por-Bajin

Abstract

Inadequate resolution is the principal limitation of radiocarbon dating. However, recent work has shown that exact-year precision is attainable if use can be made of past increases in atmospheric radiocarbon concentration or so-called Miyake events. Here, this nascent method is applied to an archaeological site of previously unknown age. We locate the distinctive radiocarbon signal of the year 775 common era (CE) in wood from the base of the Uyghur monument of Por-Bajin in Russia. Our analysis shows that the construction of Por-Bajin started in the summer of 777 CE, a foundation date that resolves decades of debate and allows the origin and purpose of the building to be established.

Evidence for European presence in the Americas in ad 1021

“…In our study, we use an advanced chronometric approach to anchor Norse activity in the Americas to a precise point in time. Exact-year 14 C results can be achieved by high-precision accelerator mass spectrometry (AMS) in combination with distinct features in the atmospheric 14 C record [20][21][22] . Measurements on known-age (dendrochronological) tree rings show that 14 C production usually fluctuates by less than 2‰ per year 23 .…”

“…The measured 14 C concentrations of tree-ring samples are matched to a reference curve through the classical statistical method of the χ 2 test 20,22 , using the following χ 2 function:…”

Isotopen in de archeologie – verleden, heden en toekomst

“…De eerste auteur is een fysisch chemicus, en dat komt daarbij goed van pas. Dat geldt zeker ook voor een vernieuwing in het laboratorium voor monsterpreparatietechnieken (zie voor een uitgebreide bespreking Dee et al, 2020). Daarnaast brengt de eerste auteur veel deskundigheid binnen voor statistische analyse van reeksen 14 C-dateringen, de zogenaamde Bayesiaanse analyse.…”

“…Dit is het doel van het huidige onderzoek van de eerste auteur, dat hij dankzij een prestigieuze ERC-onderzoeksbeurs kan uitvoeren (ECHOES, Exact Chronology of Early Societies). Het onderzoek heeft al belangrijk succes opgeleverd: de monumentale Vikingsite Por-Bazjyn in Siberië is exact gedateerd, omdat hout van de constructie het 775-Miyake event bevatte (Kuitems et al, 2020). De wetenschappelijke publicatie hiervan leidde ook tot veel aandacht in de media.…”

14C INTERCOMPARISON EXERCISE ON BONES AND IVORY SAMPLES: IMPLICATIONS FOR FORENSICS

“…Furthermore, while instrumental precision levels of the order of 0.3% in 14 C/ 12 C ratio measurement are nowadays routinely achieved, the limitations related to the calibration procedures cannot be easily overcome as they are related to global-scale or even extraterrestrial complex phenomena. And if it is true that higher resolutions, even at the annual level, have been recently shown by using large and rapid excursions of the 14 C atmospheric concentrations, they are limited to very particular situations in terms of sample material and time ranges (Wacker et al 2014;Kuitems et al 2020).…”