Page 134 - Studia Universitatis Hereditati, vol 13(2) (2025)

Mortar analysis protocol The δ C values were measured on Isotope
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The mortar sample from Beli was pretreated and Ratio Mass Spectrometer and are expressed
prepared in form of graphite targets for the ac- in per mill relative to Vienna Pee Dee Belem-
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celerator mass spectrometry (AMS) at the Za- nite and have uncertainty of 0.1‰. C con-
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greb Radiocarbon Laboratory, Ruđer Bošković tent ( C/ C values) was measured on accelera-
Institute, Zagreb, Croatia. tor mass spectrometer (AMS) at the CAIS. 14C
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Prior to preparing the sample for radiocar- values are normalized to δ C of –25‰ and ex-
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bon analysis, the sample was tested for pH us- pressed as percent modern carbon (a C) and
ing phenolphthalein to check if it was complete- as age before present (BP) (Stuiver and Polach
ly hardened (is not still absorbing atmospheric 1977; Mook and van der Plicht 1999).
CO2). Further pre-analysis included petrogra-
phy of thin layers to check for recrystallisation, Figures
134 as well as X-ray analysis to check for the pres- SRTM – Shuttle Radar Topography Mission,

ence of magnezite, which could indicate delayed NASA EarthData, https://www.earthdata.nasa
studia universitatis hereditati, letnik 13 (2025), številka 2 / volume 13 (2025), number 2
hardening (Daugbjerg et al. 2020). After all the .gov/data/instruments/srtm
tests returned negative results (no reactivity, no References
recrystallisation and no magnesite content), the
sample preparation was proceeded. Alföldy, G. 1965. Bevölkerung und Gesellschaft der
römischen Provinz Dalmatien. Akadémiai
The selected part of mortar was cryogeni- Kiadó.
cally treated (heated to 80 °C and cooled to –196 Baričević, M. 2023. ‘Kulturno-povijesna urbana
°C by liquid nitrogen, at least 5 times) and gently cjelina naselja Osor.’ Hrvatski restauratorski
broken by hammer. The sample was dry sieved zavod, 28 May. https://www.hrz.hr/aktualno
to collect 32–63 µm grain size fraction (GF). The /novosti-i-obavijesti/kulturno-povijesna
amount of carbonate as CaCO3 was analyzed -urbana-cjelina-naselja-osor/.
by producing CO2 from the known amount of Blečić Kavur, M. 2015. Povezanost perspektive:
sample. From GF a kinetic curve was developed Osor u kulturnim kontaktima mlađeg
by monitoring the velocity of CO2 production željeznog doba = A Coherence of Perspective:
during reaction with 85 % H3PO4. From the Osor in Cultural Contacts during the Late
kinetic curve the required amount of CO2 for Iron Age. University of Primorska Press and
the first and the second CO2 fraction was cal- Lošinjski muzej.
culated (Sironić et al. 2023). CO2 fractions were Blečić Kavur, M. 2021. ‘Kvarner in the Early Iron
obtained by using an equivalent amount of 2 % Age of the Northern Adriatic.’ Arheološki
HCl. From each CO2 fraction the graphite was vestnik 72:57–74.
produced and obtained C result at the Center Blečić Kavur, M., and B. Kavur. 2025. ‘Osor,
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for Applied Isotope Studies, University of Geor- Insularity and Its Surroundings: The
gia, USA (Cherkinsky et al. 2010; Krajcar Bronić Creation of a Regional Identity Caught
et al. 2010; Sironić et al. 2013). One C result was between the Global Economy and Local
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also obtained from the whole amount of the GF. Subsistence.’ In The Unclassical Balkans:
Along with each C result, the result of the C Ancient Societies and Cultures of the Balkan
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Peninsula Beside the Graeco-Roman World,
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content (δ C) was obtained. From the shape of edited by F. Milivojević, V. Sarakinski, and J.
the kinetic curve, the content of carbonate in the Tzvetkova. Filozofski fakultet Skopje.
sample, the shape of C amount vs carbon con- Borić, L. 2011. ‘Fortificiranje grada Cresa u 16.
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tent curve and δ C values of each CO2 analysis stoljeću.’ Ars Adriatica 1:133–48.
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it was decided if the extrapolated result for radi- Bradanović, M. 1999. ‘Konzervatorska studija
ocarbon date of mortar is reliable. prostorne cjeline Tramuntane na otoku