Introduction
We present the results of radiocarbon (14C) dating of archaeological prehistoric samples commissioned between the years 2016 and 2023 by the University of Wrocław and the Adam Mickiewicz University in Poznań for analysis at the Beta Analytics Laboratory in Miami (Beta Analytics), Radiocarbon and Mass Spectrometry Laboratory at Silesian University of Technology in Gliwice (Gliwice), and the Poznań Radiocarbon Laboratory in Poznań (PRL) as a part of post-excavation analyses performed within the S7 roadway contract.
As these radiocarbon age determinations have been presented only in the archaeological gray literature, that is, excavation reports (ER) and post-excavation assessments (PXA), they are not available to the wider scientific community. To facilitate further research that may be based on these results, we decided to democratize the data by providing a complete radiocarbon date list with descriptions of the sample context and comprehensive comments.
Materials
All samples used for the reported radiocarbon age measurements come from six archaeological sites located along the S7 roadway in central southern Poland in the Lesser Poland Voivodeship, in the counties of Kraków City (PL213 acc. Nomenclature of Territorial Units for Statistics – NUTS) and Kraków (NUTS PL214). The sites include the following:
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1. Domiarki 1 (99-57/83 acc. Polish Archaeological Record – PAR);
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2. Kraków-Nowa Huta-Krzesławice 41 (PAR 102-57/16);
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3. Kraków-Nowa Huta-Zesławice 88 (PAR 101-57/7);
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4. Smroków 4 (PAR 97-57/145);
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5. Szczepanowice 1 (PAR 99-57/117);
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6. Zagaje Smrokowskie 10 (PAR 98-57/70).
All the sites are located in the southern part of the Nida Basin (Pol. Niecka Nidziańska; 342.2 acc. International Geographical Union – IGU), i.e., one of three mesoregions distinguished within the Lesser Poland Upland (Pol. Wyżyna Małopolska; IGU 342). The two sites situated within the administrative borders of Kraków are located on loess hills of the south-westernmost fringe of the Proszowice Plateau (Pol. Płaskowyż Proszowicki; IGU 342.23), whereas remaining four are located in a similar landscape of the Miechów Upland (Pol. Wyżyna Miechowska; IGU 342.22; cf. Kondracki Reference Kondracki2000; Solon et al. Reference Solon, Borzyszkowski, Bidłasik, Richling, Badora, Balon, Brzezińska-Wójcik, Chabudziński, Dobrowolski, Grzegorczyk, Jodłowski, Kistowski, Kot, Krąż, Lechnio, Macias, Majchrowska, Malinowska, Migoń, Myga-Piątek, Nita, Papińska, Rodzik, Strzyż, Terpiłowski and Ziaja2018).
The remains of intensive settlement and extensive activity of prehistoric communities are well documented for the entire mesoregion, and the sites examined as part of the project are located in its main ecumenes (cf. Tunia Reference Tunia1997). The majority of the 14C-dated settlement events are archaeologically related to the Late Neolithic, Eneolithic, and Bronze Age; only a few radiocarbon age measurements were performed on samples from younger contexts, which dated to the Early Iron Age and Roman Period.
The radiocarbon age determinations related to the prehistoric settlement were obtained for 41 samples derived from 34 archaeological contexts, most of which are prehistoric burials. Consequently, the collection of organic remains submitted for dating consisted primarily of human bones (33 samples). Only in a few instances fragments of charred wood (six samples) and annual plants (two samples) were used.
Methods
Radiocarbon ages of all samples were measured with the AMS radiocarbon method mostly at the laboratory in Gliwice (Piotrowska Reference Piotrowska2013) and Poznań (Goslar et al. Reference Goslar, Czernik and Goslar2004), except for three determinations performed by Beta Analytics. In PRL, the state of preservation of collagen in bones was preliminarily assessed by analyzing C and N percentages (using the ThermoScientificTM analyzer Flash EA 1112 Series).
For bone samples, the dated fraction consisted of collagen extracted according to the Longin method (Longin Reference Longin1971), modified by Piotrowska and Goslar (Reference Piotrowska and Goslar2002) by employing an alkali solution to remove the humic substances. First, 0.5 M hydrochloric acid was used and replaced several times until the reaction was considered complete, in that the pH stabilized at < 1 and no bubbles were observed. The insoluble residues were then rinsed with demineralized water and treated with 0.1 M sodium hydroxide at room temperature for 30 minutes and rinsed to neutral pH. After a second acid bath and rinsing, the residues were subjected to gelatinization in an acidified solution (pH=3) for at least 12 hours at 85°C. In the PRL, the collagen was additionally purified by ultrafiltration (Brock et al. Reference Brock, Higham, Ditchfield and Bronk Ramsey2010; Bronk Ramsey et al. Reference Bronk Ramsey, Higham, Bowles and Hedges2004). In the Gliwice laboratory, the material obtained after gelatinization was filtered through precleaned 9 mL Ezee FiltersTM and subsequently freeze-dried (Pawełczyk et al. Reference Pawełczyk, Niedziałkowska, Pawełczyk, Piotrowska and Sykut2024).
Samples of charcoal or other plant remains (after mechanical removal of macroscopic contamination visible under a binocular microscope) were treated with the common AAA (acid-alkali-acid) procedure (Brock et al. Reference Brock, Higham, Ditchfield and Bronk Ramsey2010; Goslar and Czernik Reference Goslar and Czernik2000) unless stated differently.
Aliquots of collagen or plant remains pretreated with AAA were then combusted in a VarioMicroCube by ElementarTM elemental analyzer and graphitized in automated graphitization equipment AGE-3 (produced by Ionplus AG, Switzerland; Němec et al. Reference Němec, Wacker and Gäggeler2010; Wacker et al. Reference Wacker, Němec and Bourquin2010a). The elemental analyzer enables us to determine carbon and nitrogen content, thus indicating collagen quality by analyzing %C, %N, and atomic C/N ratio (van Klinken Reference van Klinken1999). In the PRL, the samples measuring less than 1 mg of C were combusted in closed (sealed under vacuum) quartz tubes, together with CuO and Ag wool, at 900°C for over 10 hours, and the obtained CO2 was graphitized with hydrogen (H2), using Fe powder as the catalyst.
In Gliwice, the 14C concentrations were measured using the MICADAS accelerator mass spectrometer (Synal et al. Reference Synal, Stocker and Suter2007), and the data reduction was performed in BATS software (Wacker et al. Reference Wacker, Christl and Synal2010b). The detection limit for collagen can be estimated based on the results provided by Pawełczyk et al. (Reference Pawełczyk, Niedziałkowska, Pawełczyk, Piotrowska and Sykut2024) to 45,000–48,000 14C BP. All graphites prepared in the PRL were analyzed for 14C in the “Compact Carbon AMS” spectrometers (Goslar et al. Reference Goslar, Czernik and Goslar2004).
Radiocarbon age measurements are reported in line with currently recommended standards (cf. Bayliss Reference Bayliss2015; Millard Reference Millard2014). The resulting radiocarbon ages were calibrated using the IntCal20 curve (Reimer et al. Reference Reimer, Austin, Bard, Bayliss, Blackwell, Bronk Ramsey, Butzin, Cheng, Edwards, Friedrich, Grootes, Guilderson, Hajdas, Heaton, Hogg, Hughen, Kromer, Manning and Muscheler2020) in the OxCal 4.4 package (Bronk Ramsey Reference Bronk Ramsey2009).
Results
A total of 41 successful measurements of radiocarbon age were completed (Supplementary Material 1). All the resulting 14C dates fall into a wide interval of time (ca. 4550 yr cal BCE–570 yr cal AD; 68.3%) that can be correlated with the Atlantic, Subboreal, and Subatlantic phases of the Holocene (Figure 1). The largest series of dates were obtained for multiphase sites at Kraków-Nowa Huta-Zesławice (n=19) and Smroków 4 (n=9). A Kernel density model (KDE) distribution of radiocarbon dates on finds from the first site shows four apparent peaks corresponding with the main settlement phases archaeologically dated to the Late Neolithic-Early Eneolithic, Late Eneolithic, Early Bronze Age, and Late Bronze Age (Figure 2). In the case of the latter site only two phases were dated using radiocarbon. The first series of dates provides reliable absolute dating for the Late Neolithic settlement remains, whereas the second one provides reliable absolute dates for settlement remains from the Middle Bronze Age. Also, the Final Eneolithic grave discovered at Szczepanowice provided a firm 14C-based absolute chronology. Almost all the measurements that comprise the three series are of high accuracy and precision. On the contrary, the interpretation of all dates from Kraków-Nowa Huta-Zesławice 41 and Zagaje Smrokowskie 10 poses quite a problem, as the measurements were performed on undetermined charcoals not associated with any definable prehistoric structure or event. As a result, the dates appear to be severely affected by the old-wood effect. More detailed comments on the dated archaeological contexts and adequacy of particular radiocarbon age determinations are provided separately (see Supplementary Material 2).
Modelled data (BC\AD).
Modelled data (BC).
Conclusions
We hope that this report may be used by future researchers as a resource for studies of regional chronology. Moreover, since the chronometric outcomes of the project are published, all whom it may concern are free to exploit related data and resources (such as collagen extracted from bones) available in the laboratories in Miami (Beta-measurements), Gliwice (GdA-) and Poznań (Poz-) for further scientific investigation.
Supplementary material
To view supplementary material for this article, please visit https://doi.org/10.1017/RDC.2025.21
Acknowledgments
All fieldwork and post-excavation studies were funded from public funds provided through The General Directorate for National Roads and Motorways (Pol. Generalna Dyrekcja Dróg Krajowych i Autostrad – GDDKiA). The funds were disbursed under two agreements: (1.) “Wykonanie archeologicznych ratowniczych badań wykopaliskowych w związku z budową drogi ekspresowej S-7 odcinek Moczydło – Szczepanowice – Widoma – Zastów – Kraków, wraz z opracowaniem wyników badań, w zakresie części nr 2 – Odcinek B obejmujący obszar o powierzchni 2 046,1 arów na 16 stanowiskach w m. Wielki Dół, Szczepanowice, Smroków, Zagaje Smrokowskie, Lipna Wola, Kacice, Sieciechowice, Biskupice, Poskwitów, Stary, Widoma, Domiarki” (contr. no. I/303/ZI/I-2/2015); and (2.) “Wykonanie archeologicznych ratowniczych badań wykopaliskowych w związku z budową drogi ekspresowej S-7 odcinek Moczydło – Szczepanowice – Widoma – Zastów – Kraków, wraz z opracowaniem wyników badań, w zakresie części nr 4 – Odcinek D obejmujący obszar o powierzchni 2 159,9 ara na 12 stanowiskach w m. Zastów, Kraków” (cont. no. I/304/ZI/I-2/2015). They were contracted by a consortium established between the Adam Mickiewicz University in Poznań (Pol. Uniwersytet im. Adama Mickiewicza w Poznaniu, Poznań), “Archaeologia Silesiae” Science Foundation (Pol. Fundacja Nauki “Archaeologia Silesiae”, Wrocław), and the University of Wrocław (Pol. Uniwersytet Wrocławski, Wrocław), and led by the latter institution.
We would like to express our gratitude to all the administrative, technical, and scientific staff of the mentioned and other institutions for their support. We are especially thankful for the assistance of Tomasz Goslar (PRL) and the staff of Beta Analytics, who kindly provided us with all the details of the radiocarbon age measurements performed by their laboratories.
Author contributions
Conceptualization: Tomasz J. Chmielewski
Methodology: Tomasz J. Chmielewski, Fatima Pawełczyk, Natalia Piotrowska
Software: Natalia Piotrowska
Validation: Natalia Piotrowska
Formal analysis: Tomasz J. Chmielewski, Natalia Piotrowska
Investigation: Tomasz J. Chmielewski, Ewa Dreczko, Iga Fabiszak, Mirosław Furmanek, Izabela Gomułka, Agata Hałuszko, Paweł Jarosz, Przemysław Jażdżyk, Anna Józefowska-Domańska, Lidia Kamyszek, Igor Kołoszuk, Marta Krzyżanowska, Mirosław Kuś, Mirosław Masojć, Tomasz Murzyński, Fatima Pawełczyk, Natalia Piotrowska, Marcin M. Przybyła, Agata Sady-Bugajska, Anita Szczepanek, Alicja Ustrzycka, Leszek Żygadło
Resources: Tomasz J. Chmielewski, Agata Hałuszko, Lidia Kamyszek, Marta Krzyżanowska, Mirosław Masojć, Danuta Minta-Tworzowska, Jerzy Piekalski, Natalia Piotrowska, Agata Sady-Bugajska, Anita Szczepanek, Leszek Żygadło
Data curation: Tomasz J. Chmielewski
Writing – original draft: Tomasz J. Chmielewski, Natalia Piotrowska
Writing – review & editing: Tomasz J. Chmielewski, Natalia Piotrowska
Visualization: Natalia Piotrowska
Supervision: Mirosław Masojć, Danuta Minta-Tworzowska, Jerzy Piekalski
Project administration: Lidia Kamyszek, Mirosław Masojć, Danuta Minta-Tworzowska, Jerzy Piekalski, Leszek Żygadło
Funding acquisition: Mirosław Masojć, Danuta Minta-Tworzowska, Jerzy Piekalski, Natalia Piotrowska
