The research aims to reconstruct the chronology of building the Southwest Church, Umm el-Jimal, Jordan by AMS radiocarbon dating organic inclusions uncovered from the mortars collected from the floor of the church, seat of the apse and the base of the north wall. It sheds light on the major aspects of mortar recipes at the time of their production. Samples were examined macroscopically with magnifying lenses and characterized using archaeometric techniques of optical microscopy and X-ray diffraction. The radiocarbon dates showed that 594–643 AD is the most probable age for flooring and plastering the church and 995–1154 AD is the earliest possible date for its final collapse. The preparatory layers of the church floor were laid on an older one, probably of a yard, and its north wall was raised on an older base, both most probably date to the late fifth–early sixth century AD. The production recipe of the mortars is made from a lime binder and inclusions mainly of organic (charcoal) and inorganic (quartz, grog, volcanics). The mortars have the same recipe regardless their bedding and jointing functions which remained unchanged during the building stages of church complex.

Five sites in present-day New York have played important roles in archaeological narratives surrounding the development of settled village life in northeastern North America. Excavated in the mid-twentieth century, the Roundtop, Maxon-Derby, Sackett or Canandaigua, Bates, and Kelso sites include evidence related to the transition from semisedentary settlement-subsistence patterns during the twelfth through fourteenth centuries AD to those associated with fifteenth century and later settled Iroquoian villagers. Radiocarbon dates for each site were obtained early in the development of the method and again following the transition to AMS dating. Here, we present new or recently-published dates for these sites, combined with reliable existing dates in Bayesian models, including in some cases short tree-ring sequenced wiggle-matches on wood charcoal. Our results clarify the timing of each site’s occupation(s), revealing both continuity and discontinuity in the development of longhouse dwellings, sedentism, and the repeated re-use of some site locations over hundreds of years.

Based on the study of the primary documentation related to the excavations carried out by Eurico Miller in the 1970s at Abrigo do Sol, Mato Grosso (Brazil), we propose a new reading of the stratigraphic and chronological information obtained from this rock shelter. Despite the apparent incongruity in the chrono-stratigraphic distribution of published dates, a detailed examination of the stratigraphy and field notes allowed us to identify a chronometric sequence with regular distribution between the Middle Holocene and the Late Pleistocene periods for the Abrigo do Sol site. We present here the original documents related to radiocarbon dating and their analysis. We finally show the implications of this study for understanding this site and the discussions related to the ancient settlements of the Amazon forest.

The spread of trapeze industries (the creation of trapeze-shaped flint tips) during Late Mesolithic is one of the most disruptive phenomena of technological change documented in the European Prehistory. Understanding the chronological patterns of this process requires (i) a critical evaluation of stratigraphic relationship between trapeze assemblages and radiocarbon samples, and (ii) considering different levels of chronological uncertainty according to the inbuilt age of the samples and the calibration process. In this paper, we critically evaluate and analyze the radiocarbon record of the first trapeze industries in the Iberian Peninsula. A dataset of 181 radiocarbon dates from 67 sites dated to 8800–8200 cal BP was collected and evaluated following a strict data quality control protocol, from which 135 dates of 53 sites were retained and classified according to a reliability index. Then, three different phase Bayesian chronological models were created to estimate the duration of the first spread of trapezes across Iberia, considering different levels of chrono-stratigraphic resolution. We find that trapeze industries appeared in the eastern half of Iberia, over an area of 330,000 km2 between 8505–8390 and 8425–8338 cal BP, spanning 0–85 yr (95.4% CI). When the oldest evidence of trapezes from Portugal are considered, the probability distribution expands (8943–8457 and 8686–7688 cal BP), due to the chronological uncertainty of human samples with marine diet and regional ΔR values applied. For the eastern half of Iberia, the current evidence indicates a very rapid spread of trapeze industries initiated in the Central-Western Pyrenees, suggesting cultural diffusion within Mesolithic social networks as the main driving mechanism.

In the hyperarid eastern Sahara, west of the Nile River in Egypt, areas with vegetated eolian mounds have attracted people and animals because of shallow groundwater that at times of high water tables may be reached by hand digging shallow wells. An eolian phreatophytic mound with a living arak bush (Silvadora persica L.) on top, one of three known from this region of SW Egypt, provided a stratigraphic record of its growth. The geochronology of the mounds aggradation and that of a nearby tarfa mound (Tamarix nilatica Bunge) was determined by radiocarbon dating plant macrofossils within the stratigraphic succession. Eolian aggradation of the mound postdates deflation that eroded playa sediments of the Neolithic pluvial that ended ca. 5000 BP and appears to be due to a resurgence of the shallow aquifer. Subsequent deflation of the mounds is apparently due to post-1500 BP aridity. Regional vegetation is described in the Appendix I.

The study of human remains can provide valuable information about aspects of past populations. Here we present an updated database consisting of 590 radiocarbon (14C) dates for human remains from Holocene South Africa before European contact. We calibrated or recalibrated all the previously published dates using the most recent calibration curve for the southern hemisphere. Each date is roughly georeferenced and plotted according to their Stone Age or Iron Age contexts, revealing the broad distribution pattern of dated Holocene human remains across South Africa—perhaps reflecting aspects of past population distribution and densities, but also underscoring historical collection practices, archaeological research focus, and preservation conditions. We use Kernel Density Estimation models to show peaks and troughs of dated remains through time, with Later Stone Age peaks at ∼5.5 ka cal BP, ∼2 ka cal BP and ∼0.5 ka cal BP, and Iron Age peaks ∼1.1 ka cal BP and ∼0.5 ka cal BP, some of which show broad correspondence to climatic data. Our data, based on dated remains only, do not provide a full reflection of past populations, and our large-scale, coarse-grained analysis cannot yet assess the reasons for the peaks in dated human remains in detail. Yet, the study provides a new resource, and a data-driven overview that highlights aspects to be explored with further contextual analyses against the available archaeological records, population histories and climatic indicators through time and across space.

Preparation of bones for radiocarbon (14C) dating is still quite a challenge for researchers. The methods are being tested and improved, to increase reliability of dating results and to verify the previous ones. In this work, a set of gelatine samples, extracted from Cervus elaphus and Cervus canadensis bones from various sites in Europe and a set of human bones from archaeological sites in Poland were subjected to retreatment using ultrafiltration in Gliwice Radiocarbon Laboratory. The tested samples represent a wide range of ages, from older than 40,000 14C years BP to modern. The prepared material was subjected to the measurement of C/N atomic ratios and 14C dating using the accelerator mass spectrometry (AMS) technique. Also, the stable isotopes (δ13C and δ15N) values were determined. In a few cases ultrafiltration allows to improve gelatine quality for long-stored samples, by increasing the %C and %N as well as decreasing C/Nat ratios. Nevertheless, this effect was not observed for majority of the samples. Remeasurements of long-term stored samples give mostly the same 14C ages for ultrafiltered ones and for those without ultrafiltration.

In 2021, a series of radiocarbon dates for St. George’s Rotunda in Nitrianska Blatnica (Slovakia) was published. The samples were acquired during restoration work. Based on the analysis, the authors dated the rotunda to the period of around AD 820–887, with 86% of the probability distribution lying in the period before AD 863. The chronology is based on the combined radiocarbon date 1191 ± 10 BP, which was obtained from four samples of wood fragments found in the oldest mortar layer. However, the date proposed by the authors raises concerns. The conclusions were based on a selection of samples and modeling of radiocarbon dates but put less emphasis on the results of many years of broad archaeological research on the local settlement agglomeration as well as extant historical and archaeological knowledge. The present re-analysis of the early medieval mortar and plaster samples and simple modeling corroborates the alternative hypothesis, providing us with the date 1115 ± 13 BP (cal AD 892–988 2σ). The resulting probability range is consistent with current archaeological and historical knowledge. Consequently, contrary to former conclusions, the construction of the rotunda should be dated to the period between the end of the 9th century and the end of the 10th century.

This paper offers a temporal analysis of the megalithic group of La Lora in the context of northern Iberian Plateau megalithism. For this purpose, 67 accelerator mass spectrometry radiocarbon (AMS 14C) dates were obtained on human bone from the minimum number of individuals recovered from nine tombs. This is the first systematic dating project carried out in this dolmen group and has enabled the chronology of the main funerary series to be updated. The results reveal that the actual funerary use dates mainly to the 4th millennium BC, although, as deduced from the archaeological material, some tombs were reused in later periods. Additionally, the significant architectural polymorphism of the group, consisting mainly of simple dolmens and large corridor tombs, suggested a temporal evolution to monumentality. However, the dating shows a more complex reality, since it is likely that the large tombs functioned as funerary pantheons during the 4th millennium BC, characterized by a cyclical and recurrent use. In contrast, the simpler structures were preferred to be of shorter use and restricted to the first half of the 4th millennium.

Horizontal watermills in the southern Levant have proved difficult to date. This study investigates the use of radiocarbon (14C) dating of various organic carbon fractions in structural mortars and carbonate deposits to identify terminus post quem (TPQ) construction dates for seven arubah watermills and two chute watermills in northern Jordan. Dating results from the various organic fractions are discussed in the contexts of carbon fraction integrity and mortar type. The arubah watermill construction dates fall into two chronological groups. Four arubah watermills have Middle Islamic (late 12th to early 14th century AD) construction dates based on macrocharcoal and bulk organic fraction ages, whereas the bulk organic fraction ages of two earlier arubah watermills straddle the Byzantine-Early Islamic transition. Their possible fifth to seventh-century construction dates are among the earliest in the southern Levant. Limited 14C data from the chute water mills suggests that the earliest may date to the sixth–seventh century period, concurrent with the older arubah watermills. The study supports the viability of the AMS 14C method to provide estimated TPQ construction dates for watermills, providing caution is exercised. Short-lived macrocharcoals have the highest integrity but are subject to severe sample loss during pretreatment. 14C ages from humic and humin fractions in earthen mortars are influenced by “old carbon” contamination, possibly a soil reservoir effect, and are centuries older than the probable construction date. Attention is drawn to the potential use of arubah carbonate deposits as proxy records of water flow, watermill use, and hydroclimate.