Absolute radiocarbon dating offers high precision, but its application to historical contexts, such as the Inca civilization, requires a rigorous methodological approach. This research examines methods to enhance chronological accuracy through a case study of artifacts from the Llullaillaco Capacocha sacrifice. Focusing on short-lived organic remains, it combines radiocarbon and stable isotope analyses (carbon, nitrogen, and oxygen) to produce accurate age estimates aligned with ritual activity. To overcome hemispheric calibration issues, the study uses simulation and chronological modeling to refine temporal frameworks. This strategy advances our understanding of Inca ritual timing and broader cultural developments beyond colonial accounts by highlighting the late performance of the capacocha ritual in the context of the Inca Empire.

The Salapunku archaeological site is located within the Historic Sanctuary – National Archaeological Park of Machu Picchu (HS-NAPM) in the Cusco area of Peru. Although Salapunku is related to the Inca settlements of the HS-NAPM, during archaeological excavations, we distinguished different moments of cultural occupation from the earliest human presence to complex pre-Hispanic societies such as the Inca and finally to the colonial period. Previous research on the site’s chronology was based on typological analyses of pottery and other artifacts found during archaeological research. This radiocarbon analysis, the first of its kind in this area, establishes a chronology of the cultural history of this significant settlement, considered the gateway to the Cordillera of Vilcabamba.

This study focuses on reconstructing paleoclimate changes between 830 BC and 650 BC, a period of critical significance marked by the Hallstatt Catastrophe, a shift from a warm and dry climate to a cool and humid one. This period also coincides with the onset of the plateau on the radiocarbon calibration curve. The research material consisted of oak tree trunks G24 and G58, discovered in Poland (Grabie village). Dendrochronological methods were employed to date the two trunks. The identification of the Miyake event around 660 BC in the Delta 14C results from the Grabie tree rings corroborated the dendrochronological dating. This study presents an analysis of changes in stable carbon isotope composition in alpha-cellulose extracted from annual growth increments and variations in growth ring widths.

This study examines Neltuma pallida wood from the Cerro Laguna archaeological site in coastal Peru to establish a floating chronology and absolute dating. Ten cross-sections yielded a 70-year chronology (CLAA1). Alpha-cellulose was extracted from five single growth rings from one sample for radiocarbon dating, then wiggle-matching in OxCal v4.4 using SHCal20. Results place the youngest ring at 1314-1330 CE (95.4% probability), situating the full sequence in the period between 1253 and 1322 (+/- 8) CE. Statistical analyses show a robust dendrochronological signal, and ring-width data suggest strong El Ni & ntilde;o Southern Oscillation (ENSO) events around 1300 CE. These findings confirm Cerro Laguna's Late Intermediate Period occupation and allow us to assume that the entire 70-year period can be used to improve the calibration curve for the Southern Hemisphere.

This paper presents new radiocarbon (14C) measurements from annual tree rings of English oak (Quercus robur L.) from Kujawy, Poland, spanning 1042-1062 CE. The results confirm an increase in Delta 14C values between 1053 and 1055 CE, within the Oort Minimum of solar activity, consistent with literature values (Brehm et al. 2021a; Eastoe et al. 2019; Terrasi et al. 2020). The data reveal a sustained increase in Delta 14C values between 1053 and 1055 CE, rising from -6.9 +/- 1.8 parts per thousand to -2.6 +/- 1.8 parts per thousand. For the preceding period (1042-1052 CE), the average Delta 14C value is -11.0 +/- 1.9%, indicating a significant increase of 8.4 +/- 2.6 parts per thousand toward 1055 CE. The study estimates the 14C production rate during this period and suggests the radiocarbon increase likely began before 1054 CE, indicating it is unlikely to be significantly attributed to the supernova in 1054 CE. The study contributes to refining the understanding of rapid changes in atmospheric radiocarbon and their potential causes.

The rapid increase in tree-ring radiocarbon concentration of 12 parts per thousand between 774-775 CE marked the first confirmed cosmic-origin event identified through annual tree-ring records. Subsequent studies have independently verified this signal in dendrochronologically dated material from multiple regions, confirming its global nature. Since then, several comparable events have been identified across different periods. These radiocarbon spikes are of particular importance because they provide precise annual tie-points that can significantly improve chronological resolution in fields such as archaeology and geology. In this paper, we present a simple method for detecting such events in high-resolution radiocarbon datasets.

With the development of radiocarbon dating methods in the last decade, the Andean archaeological community has successfully leaned into the problem of the chronology of the expansion of the Inca State. While this chronology was based on ethnohistorical accounts (Rowe 1945), it has been possible to verify its foundations precisely in the last decade. The results from the Maucallacta region are part of these discussions and are intended to add new data from the Inca province of Kuntisuyu, which was neglected in this debate until now. The project encompasses archaeological investigations near the snow-covered volcano Coropuna, frequently mentioned by chroniclers of the 16th and 17th centuries as an oracle worshiped since pre-Inca times. This includes a large complex known as Maucallacta-Pampacolca, located approximately 170 km northwest of Arequipa in the southern highlands of Peru, within the District of Pampacolca, Province of Castilla, Department of Arequipa (LS; 3750 m asl). Due to its location, it holds a unique relationship with the Coropuna landscape. The site is a vast administrative center featuring over three hundred stone buildings, tombs, and ceremonial structures. Among them, the most important is the large ceremonial platform with ushnu and the dumps deposited beneath it. The analysis of ceramics and animal bones, combined with stratigraphic analysis and the results of new calibrations and interpretations of radiocarbon dates, provides a comprehensive picture of the formation and use of ceremonial dumps at the site, making them one of the most thoroughly examined collections in this regard.

The rapid increase in tree-ring radiocarbon concentration of 12‰ between 774–775 CE marked the first confirmed cosmic-origin event identified through annual tree-ring records. Subsequent studies have in-dependently verified this signal in dendrochronologically dated material from multiple regions, confirm-ing its global nature. Since then, several comparable events have been identified across different peri-ods. These radiocarbon spikes are of particular importance because they provide precise annual tie-points that can significantly improve chronological resolution in fields such as archaeology and geology. In this paper, we present a simple method for detecting such events in high-resolution radiocarbon da-tasets.

Radiocarbon dating is a widely used method in archaeology and earth sciences, but the precision of calibrated dates from single radiocarbon measurements can be difficult to understand. This study investigates the precision of calibrated radiocarbon dates depending on the uncertainties of the measurement and the details of the calibration curve. Using data for the Holocene epoch and the IntCal20 calibration curve, over 1,000,000 hypothetical radiocarbon measurements were calibrated and analyzed. The study shows that high-precision measurements can yield calibrated date ranges from less than 50 years to more than 200 years (at the 95.4% probability) depending on the specifics of the calibration curve. This research may serve as a tool for planning future studies and assessing whether high-precision measurements are beneficial for proposed case.

Abstract. Temperature reconstruction was carried out on the basis of a centuries-long dendrochronological scales from Austrian Alps. Chronologies of growth-ring width, maximum density of latewood and stable isotope content of carbon and oxygen were applied for the research. Subfossil wood and living trees originating from the area of Schwarzensee Lake were used for the construction of the chronologies. All measurements were performed with annual resolution. A very good match was found between the results obtained and the meteorological data, making it possible to precisely reconstruct the temperature of the growing season (May–September) over the years 800–2000 CE. The proportion of temperature variance explained by independent variables accounted for 52 % in the period common for the growth-ring chronologies and meteorological data. The statistics calculated during calibration and verification tests indicated that chronologies have high reconstruction skills and that the accuracy of reconstruction is good. Obtained data show the existence of significant cooling in the periods 900–1100 CE, 1275–1325 CE, 1450–1600 CE and 1800–1890 CE and evident warming around the years 1150 CE, 1250 CE, 1325–1425 CE, 1625–1775 CE. The strongest increasing trend in temperature has been observed since the beginning of the 20th century and is clearly indicative of an ongoing climate warming.

ABSTRACT The floating dendrochronological sequence of pine wood from Józefowo, N. Poland was expected to cover the ∼660 BC radiocarbon ( 14 C) excursion. The sequence was radiocarbon dated using the OxCal wiggle matching procedure and the IntCal20 calibration curve. 14 C concentrations were measured in one-year α-cellulose samples from around 660 BC. The published data on the ∼660 BC 14 C excursion from Grabie, Poland were used to absolute date the Józefowo chronology with 1-year accuracy. The results confirm the occurrence of a rapid increase in Δ 14 C in 664/663 BC and its potential to be used as a fixing point for floating dendrochronological sequences.

ABSTRACT The Early Iron Age hillfort in Chotyniec (SE Poland) is the westernmost permanent settlement of the Scythian cultural circle. Recognizing the construction of the fortified settlement’s ramparts and their chronology was considered one of the priorities of the systematic research conducted since 2016. Based on 18 radiocarbon dated samples from different parts of the rampart, a chronological model of its functioning was made. It indicates that the construction of this monumental fortifications protecting the settlement in Chotyniec should be dated to between 651–595 or 531–409 BC. This dating synchronizes well with the chronology of the most important ritual and ceremonial object within the Chotyniec settlement—the so-called zolnik and other Scythian settlements from the East European forest-steppe zone.

ABSTRACT The article presents results of measurements of radiocarbon ( 14 C) concentration in sub-annual dendrochronologically dated tree rings of English oak ( Quercus robur L.) from Grabie village near Kraków (southern Poland). Samples of early wood (EW) and late wood (LW) spanning the years 664–658 BCE. α-cellulose was extracted from each sample and their radiocarbon content was measured at the ATOMKI laboratory in Debrecen, Hungary. The EW and LW data confirm a prolonged increase in Δ 14 C values around 665–663 as was observed by Park et al. (2017), Rakowski et al. (2019), or Sakurai et al. (2020). In addition, we found that this event may consist of two relatively small events, as was proposed by Sakurai et al. (2020). Based on obtained in this and previous study data we estimate that the occurrence of the two events were between 665 and 664 BCE (Rakowski et al. 2019), and in late spring of 663 BCE (May–June, before beginning of LW formation).

ABSTRACTThis article presents measurements of the radiocarbon (14C) concentration in sub-annual tree rings. Samples of earlywood (EW) and latewood (LW) from dendrochronologically dated tree rings (English oak, Quercus robur) from Kujawy, near Kraków (Poland), spanning the years of 990–997 CE, are extracted and their 14C content is measured at the Center for Applied Isotope Studies at the University of Georgia, USA. The EW and LW data show a gradual increase in the Δ14C values between 991–995 CE, which are similar to those observed by Rakowski et al. (2018). An increase of 10.3 ± 2.6‰ in Δ14C for the EW data, and 8.6 ± 2.6‰ for the LW data has been recorded for this period. Using this data, it is possible to estimate the time period for when a major historical event occurred, which seems to have been in the late summer (September –2/+1 month) of 993 CE.

This study presents a new stable oxygen isotope chronology, covering the years 800-2000 AD, constructed using modern and subfossil wood derived from trees growing around Lake Schwarzensee in Austria. The climatic signal imparted in the chronology is conditioned mainly by the direct influence of environmental factors on the isotopic signature of source water, which in turn is regulated by evaporation and condensation mechanisms. The second driver of stable oxygen isotope is the physiological response of trees to changing weather conditions, most importantly rates of transpiration. The chronology of stable oxygen isotopes corresponds well with both temperature (r = 0.485; p < 0.05) and total precipitation (r = -0.548; p < 0.05) during the growing season (May-September). This mixed signal results from the fact that the relationship between the content of stable oxygen isotopes and the influence of climate is multifactorial. Moreover, the effect exerted by meteorological conditions on stable isotope ratio changes over time. This is most probably linked to interannual variation in climatic and environmental factors.

ABSTRACTDetermining the biocomponents in liquid fuels using radiocarbon radioisotope (14C) dating requires sample preparation adaptations to the conditions of the Gliwice Radiocarbon and Mass Spectrometry Laboratory. Liquid scintillation counting (LSC), and accelerator mass spectrometry (AMS) were investigated using six samples, including one 14C-free fuel and modern hydrotreated vegetable oil (HVO). For AMS, samples were prepared using tin capsules for liquids for EA combustion and graphitization in an AGE system. For LSC, liquid fuels were prepared by mixing with purified preheated sand and a benzene synthesis line. Benzene resublimation was also tested. IRMS measurements were also conducted for benzene to account for isotopic fractionation. Sample background measurements using both methods showed good performances by both AMS and LSC without resublimation. Comparable results were also obtained for HVO.

ABSTRACTThe chronology of Machu Picchu was traditionally associated with the period attributed to the reign of Pachacuti Inca Yupanqui. Within the scheme of the so-called “historical chronology”, proposed by John H. Rowe in 1945, the ascension to power of Pachacuti Inca took place around 1438 CE, and the construction of Machu Picchu began by 1450–1460 CE. Several radiocarbon-dated samples may help to understand the chronology of the construction of llaqta of Machu Picchu, Chachabamba, and Choqesuysuy. However, there is a lack of consensus between different radiocarbon-based Inca chronologies because of the lack of information of which calibration curves to use: Northern Hemisphere (NH), Southern Hemisphere (SH), or a mixed calibration curve? Thus, the main goal of the present investigation is to develop a new methodological approach to reconstruct a radiocarbon-based Incan chronology, an approach based on the determination, through modeling, of the proportion of NH and SH air parcels arriving at three relevant Inca settlements. We found air parcel contributions from the NH and SH for Machu Picchu (51% NH and 49% SH), Chamical (29% NH and 71% SH), and Tiquischullpa (41% NH and 59% SH). Thereby, our investigation brings three proportions to mix NH and SH14C curves, based on an empirical method and supported by a high-resolution paleoclimatic tracer, for Inca radiocarbon dating studies. Our study emphasizes that great attention should be paid when applying radiocarbon calibration to radiocarbon measurements of samples originating from regions under the influence of the atmospheric circulation-boundary between hemispheres.

ABSTRACTAccording to the classical chronology of the Inca State, the ascension to power of Pachacuti Inca took place around AD 1438 and the construction of Machu Picchu began by AD 1450–1460. However, the improvement in the accuracy of radiocarbon (14C) dating resulting from the application of Bayesian analysis has changed our view of the historical chronology. This new research raises questions about our understanding of the cultural development of the Machu Picchu area, in the light of the new proposed chronological scheme. This paper presents a set of 11 new14C dates, derived from AMS, from the sites of Llaqta of Machu Picchu, Chachabamba, and Choqesuysuy. The latter two sites are situated within the Machu Picchu National Archaeological Park (Arqueología del Santuario Histórico Nacional y Sitio Patrimonio Mundial de Machu Picchu) and have been interpreted as being part of the contemporary Late Horizon Inca landscape. The new14C ages are modeled using Bayesian inference and present a revised dating framework for these sites and their chronological relationship with Llaqta of Machu Picchu.

Investigating seedling germination, plant growth and flowering in simulated microgravity conditions in a clinostat is not only of academic interest, but also a highly important issue for long-term space missions. Another factor influencing plant growth and flowering, from that point of view, is the earth magnetic field which cannot be switched off simply, either, but is thus less often investigated. Here we give an overview of recent technologies and findings related to the influence of gravity - or its real or simulated absence - and magnetic fields on germination, growth and flowering of typical model plants like Arabidopsis thaliana and more space-travel related plants useful for feeding astronauts. In addition, we suggest a novel combined system to investigate plants in combinations of microgravity and freely definable magnetic fields.