Page 127 - Studia Universitatis Hereditati, vol 13(2) (2025)

tained may be unclear, they can provide a means

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Figure 5: A Geophysical Survey of the Main Square in Beli with a Handheld Ground-Penetrating Radar System (elab-
orated by Nives Doneus, 2024)

Mortar Analysis of acquiring chronological information from
Research in the Osor region indicates that ar- structures like bridges (Sironić et al. 2022) or aq-
chaeological remote sensing is especially effec- ueducts (Sironić et al. 2019) that otherwise could
tive at demonstrating the diversity, extent and not be dated.
complexity of past land use (Doneus et al. 2024). Radiocarbon dating of mortar is based on
Many of these traces have not been classified as the fact that, during hardening, the lime in the The Roman Urbanisation of the Northern Adriatic Island of Cres
archaeological remains or sites and have received mortar absorbs CO₂ from the atmosphere and
little attention in archaeological research. One preserves it in the binder as calcite (CaCO₃), thus
reason is certainly the fact that, until recent- containing information about the date of forma-
ly, archaeological methods could not deal with tion (Daugbjerg et al. 2020). However, the dat-
large-scale land use remains that did not contain ing of mortars is not straightforward, since, in
any datable finds. However, these are not the addition to the binder calcite, mortars also con-
only archaeological category difficult to date. tain carbonates from other sources, such as ag-
Stone structures or buildings, with or without gregate, unburned carbonate rock used for lime
mortar binding, can also pose a challenge when production and recrystallised carbonates.
additional dating information is lacking. Furthermore, the quality of the mortar com-
Dating building structures with mortar promises the accuracy of the radiocarbon dating.
binding is often difficult when using construc- As there is still no universal method for the ra-
tion techniques as a primary reference. Even if diocarbon dating of mortar, physical analysis
early Roman, late Roman and early medieval (petrography and XRD) and chemical analysis
walls can be visually distinguished from each (carbonate content, kinetic curve, carbon stable
other and apparently use different mortar bind- isotope content (δ C) and relation of radiocar-
13
ings, their respective dating remains only an es- bon content (a C) of CO2 fractions) must be
14
timate without the accompanying archaeologi- considered in parallel. To further confirm dates
cal material. Although mortar analyses cannot obtained through mortar dating, different ap-
always be applied successfully, and the dates ob- proaches involving dating of inclusions, sequen-