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Ramped pyrolysis radiocarbon dating was carried out on lime lumps from what was believed to be the oldest remains of Turku Cathedral, Finland, the first sacristy. Lumps extracted from bulk mortar from five sampling locations were analysed. For each sample, 5–6 fractions of CO2 from different temperature fractions were radiocarbon dated.One of the five samples exhibited significant contamination for its lowest temperature fractions. For the remaining samples, the age-temperature profiles were well-behaved, exhibiting a plateau of dates that were in statistical agreement and indicative of samples where only a single carbonate source (lime binder from the construction phase) is contributing to the radiocarbon dates. For each of the five samples, the combined radiocarbon age resulted in a calibrated age with a large probability distribution mode (typically > 85% probability) in the late 13th century AD. Combining the radiocarbon dates from all five samples (21 fractions in statistical agreement, χ2-test: df = 20, T = 7.1, 5% = 31.4) provided an age of 709 ± 11 yr BP and a calibrated age of 1276–1296 cal. AD (95.4%). This result finds excellent agreement with historical sources, previous mortar dating work, and a single radiocarbon date on organic material also embedded in some of the bulk mortar.The results demonstrate that ramped pyrolysis, applied to well-selected lime lumps, is (A) a useful diagnostic tool for establishing how reliable a sample is and (B) an accurate, precise, and repeatable technique for radiocarbon dating mortar. The results further confirm that Turku Cathedral's first sacristy was constructed from stone and mortar in the late 13th century AD.Additionally, using Turku Cathedral sacristy as a case study, two Bayesian models were presented to illustrate how, in general, mortar dating and Bayesian statistics might, in future, be applied to examine building construction dynamics for the case of (chronologically) ordered or unordered mortar derived radiocarbon dates.

Geophysical investigation of a former convent graveyard for conversion to a community centre identified an unrecorded, unmarked burial below a later burial. Archaeological excavation confirmed the presence of skeletonized human remains, considered by police as a possible clandestine burial. Mortuary examination indicated the remains belonged to a mature adult female. To determine whether the deceased could be a recorded missing person, radiocarbon dating was undertaken on a femur and a rib bone. This is not always straightforward, and results showed two possible ages due to intercepts on either side of the nuclear weapons testing spike in atmospheric 14C; however, the later dated burial allowed us to constrain the date of a rib to CE 1959. This study demonstrates that dating a second tissue with a longer turnaround time, such as a femur, can help to constrain which side of the bomb spike is most probable. This paper documents in one work the search, scene and sample and then advances this to resolution by anthropological analysis and radiocarbon dating of human remains.

Caves containing perennial ice deposits make up a little-known, but emerging part of the cryosphere under increasing scrutiny from the scientific community. M-17, a sag-type ice cave opening at 1879 m asl in the Tolminski Migovec massif of the Julian Alps (NW Slovenia) contains a perennial underground ice deposit whose paleoclimate sensitivity is poorly understood and whose longevity under current climate change is at risk. The past mass balance of this cave is constrained using wood macro-remains embedded in ice. Accelerator mass spectrometry radiocarbon dating of 18 wood samples embedded in ice provides the largest currently available dataset for a subterranean ice deposit in the southern European Alps. The reconstructed chronostratigraphy reveals three main phases of likely positive ice balance around 900–1100 AD, 1200–1300 AD, and 1700–1800 AD, as well as a period of negative mass balance around 1300–1400 AD. The onset of cave glaciation is deemed to have occurred no later than about 900 AD, with evidence of overall positive ice mass balance during multi-decadal periods characterized by cooler-than-average summers and wetter-than-average springs. Conversely, negative mass balance is recorded during a period warmer-than-average summers and dry springs. The cave has experienced ice mass loss since its discovery in the 1980s.

In this paper we evaluate the extent of freshwater reservoir effects (37 samples across 12 locations) and present new data from various archaeological sites in the Eurasian Steppe. Together with a summary of previous research on modern and archaeological samples, this provides the most up-to-date map of the freshwater reservoir offsets in the region. The data confirm previous observations highlighting that FREs are widespread but highly variable in the Eurasian Steppe in both modern and archaeological samples. Radiocarbon dates from organisms consuming aquatic sources, including humans, dogs, bears, aquatic birds and terrestrial herbivores (such as elk feeding on water plants), fish and aquatic mammals, as well as food crusts, could be misleading, but need to be assessed on a case-by-case basis.

Mid-latitude alpine caves preserve a record of past solid precipitation during winter, locally spanning several centuries to millennia. Dating organic macro-remains trapped in ice layers allows the determination of timing and duration of past periods of positive and negative ice mass balance. We present here the largest comparative study of ice cave sites yet published, using Bayesian age-modelling on a database comprising 107 radiocarbon dates, spread over eight caves in the Austrian Alps. We show that periods of positive mass balance coincide with past glacier advances. We find unconformities rich in organic macro-remains dated to the Medieval Climate Anomaly (between 850 and 1200 CE) marking widespread ice retreat. We demonstrate positive ice mass balance at all studied sites for the Little Ice Age, coinciding with the largest glacier advances in the Holocene between 1400 and 1850 CE. At the sites with records spanning over 2000 years, positive mean annual mass balance is also observed during the periods 300 BCE–100 CE and 600-800 CE. These subterranean ice deposits show widespread evidence of accelerated negative mass balances in recent years and their record is under imminent threat of disappearing.

International audience; Evidence for climate variability in the Southern African monsoon region (SAMR) is limited by a spatially and temporally discontinuous palaeoclimatic dataset. We describe a 6680 year long, largely sub-decadal resolution δ 15 N record from a rock hyrax midden from southeastern Africa. The results provide a detailed reconstruction of regional hydroclimates since the beginning of the mid-Holocene. A long-term-albeit subtle-increase in humidity consistent with precessional forcing is observed, but the record is dominated by a strong ~1750-yr cycle, a signal that is shared with other SAMR records. Considered in their regional context, these data suggest that changes coincident with the termination of the African Humid Period at ~5500 cal BP do not express the abrupt transition observed in some records from the northern African tropics. Rather they indicate gradual changes, as observed at peri-equatorial sites. Notably, however, eastern and western subregions of the SAMR experience a rapid phase shift beginning ~5500 cal BP, with initially in-phase hydroclimate anomalies transitioning to the establishment of a strong east-west dipole. This likely reflects a coeval strengthening of the Southeast Atlantic trade winds and decreased atmospheric pressure in southeast Africa, factors associated with increasing (decreasing) austral (boreal) summer insolation. The results highlight the distinct nature of southern African responses across this key period of African climate history.

Despite the rich archaeological heritage present in the Limfjord region in Denmark, few palaeodietary studies using human and animal bone material from this area currently exist. This paper aims to investigate the palaeodiet as well as animal husbandry strategies in this region during prehistoric times, from the Mesolithic to the Viking Age using stable isotope analysis. New stable isotope results from almost 300 human and animal bones are presented here, as well as their comparison with previously published data. Higher δ15N values in sheep/goats than cattle suggest that cattle were more confined while the sheep/goats were allowed to roam and possibly consume salt-marsh grass. The stable isotope results reveal a rise in δ15N ratios in human individuals from the Iron Age, which is most likely related to the combined effects of fertilisation practices and aquatic protein consumption. Additionally, evidence for marine exploitation in the form of shell middens and fish remains can be linked to periods characterised by climatic deterioration.