Sudden annual rises in radiocarbon concentration have proven to be valuable assets for achieving exact-year calibration of radiocarbon measurements. These extremely precise calibrations have usually been obtained through the use of classical χ2 tests in conjunction with a local calibration curve of single-year resolution encompassing a rapid change in radiocarbon levels. As the latest Northern Hemisphere calibration curve, IntCal20, exhibits single-year resolution over the last 5000 years, in this study we investigate the possibility of performing calibration of radiocarbon dates using the classical χ2 test and achieving high-precision dating more extensively, examining scenarios without the aid of such abrupt changes in radiocarbon concentration. In order to perform a broad analysis, we simulated 171 sets of radiocarbon measurements over the last two millennia, with different set lengths and sample spacings, and tested the effectiveness of the χ2 test compared to the most commonly used Bayesian wiggle-matching technique for temporally ordered sequences of samples such as tree-rings sequences, the OxCal D_Sequence. The D_Sequence always produces a date range, albeit in certain cases very narrow; the χ2 test proves to be a viable alternative to Bayesian wiggle-matching, as it achieves calibrations of comparable precision, providing also a highest-likelihood estimate within the uncertainty range.

To investigate the environmental history of the Tisza River (Hungary), we applied 14C and OSL dating methods for five parallel, neighboring cores from the flood plain area (Jászság Basin). Four major sedimentary layers were identified: meadow soil on the top (S1); silty-clay (S2); clayey-silt (S3) section; and fine sand (S4). 14C and OSL data were integrated into a synthetic age-depth model using the BACON software package. Formation of the S1 layer (depth: 0–1.0 m) falls in the Holocene, up to 10 kyrs cal BP, with moderate sedimentation rate (100 yr/cm aAR). The S2 layer (1.0–8.0 m depth) represent the entire Last Glacial to Upper Pleniglacial period (19–27 kyrs cal BP), with a much faster sedimentation (20 yr/cm aAr). The S3 section (8.0–17.0 m) represents a longer period (27–45 kyrs cal BP) with similar sedimentation rate (19 yr/cm aAr) as S2. These clayey silt layers fall into the Late Pleistocene/Middle Pleniglacial period, a period of nearly 18 kyrs of sedimentation resulting ∼9 m thick sediment. Our study delivered some new and important details about the surface evolution of the investigated Tiszasüly area. A missing part of about 10 kyrs period (between 10–19 kyrs cal BP) was revealed in the investigated synthetic cores.

Earthworm biospheroids are a useful alternative to radiocarbon (14C) soil dating. In this study, we undertook a series of measurements to test the 14C dating potential/performance of recent earthworm biospheroid granules. A novel sample preparation protocol for 14C in biospheroids was developed and elaborated at Atomki (Institute for Nuclear Research) and tested on IAEA reference materials. 24 natural biospheroid samples were extracted from five different location/environment-eight topsoils (A-horizon soils). Bomb-peak-based, high-resolution 14C dating show very uniform 14C results at 105.6 ± 2.6 pMC (1σ) and none of the biospheroids are older than 30 yr. It also shows that no biospheroid with a 14C bomb-peak as high as that observed in the 1960s and 1990s were observed. The results confirmed that earthworms do indeed consume almost exclusively recent biogenic carbon, not other organic compounds or inorganic carbonates previously bound in the soil. The calendar age of their biospheroids were extremely close to the real (zero) age of the surface. Thus, no “reservoir effect” is seen for these macrofossils. We conclude that a biospheroid-based 14C age determination method may be suitable to measure the burial time as long as earthworm biospheroids can be found in the soil.

This paper presents the results of accelerator mass spectrometry radiocarbon (AMS 14C) dating performed on archaeological samples (human bone, wood charcoal, and other charred plant macro-remains) from six sites located in the Lesser Poland Upland (southern Poland). We report 41 14C age measurements performed on discoveries made during the contract excavations carried out during the S7 roadway construction from 2016–2022. The resulting ages fall into a long interval, which, in terms of the regional archaeological periodization, lasts from the Late Neolithic to the Late Antiquity/Early Medieval Period (ca. 4600 BC–600 AD), and in terms of the climatological periodization corresponds to the Atlantic, Subboreal, and Subatlantic.