Naslov
Stratigraphic database for the determination of provenance of limestone used in Colonia Julia Emona (Regio x, Italia)

Autori
Brajkovič, Rok ; Žvab Rožič, Petra ; Djurić ; Bojan ; Županek, Bernarda ; Cvetko Tešović, Blanka ; Holcová, Katarína ; Gale, Luka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts, ASMOSIA XIII 13th International Conference of the Association for the study of marble and other stones of antiquity / Schwarnthorer, Thomas ; Anevlavi, Vasiliki - Beč : Austrian Archaeological Institute at the Austrian Academy of Sciences Kunsthistorisches Museum Vienna, 2022, 27-28

Skup
13th International Conference of the Association for the Study of Marble and Other Stones of Antiquity

Mjesto i datum
Beč, Austrija, 19.09.2022. - 24.09.2022

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Multimethod analysis, limestone provenance, stone products

Sažetak
Colonia Iulia Emona (mod. Ljubljana) was a Roman town in Regio X in present-day central Slovenia. Several quarry areas of limestones used by the Romans have been proposed up to now, stratigraphically ranging from the Lower Triassic Werfen, Lower Jurassic Podbukovje (Krka Limestone Member, Lithiotid Limestone Member, and Spotty Limestone Member), Middle Jurrasic Laze, Upper Cretaceous Lipica, and Miocene Laško Formation (Lithothamnium Limestone Member). However, high-resolution stratigraphic data from the proposed quarry areas, as well as detailed analyses of microfacies and geochemical composition of stone products is missing. We examined stratigraphically successions on the proposed quarry areas and the lithology of the stone products to create a multimethod database that would increase confidence in provenance determination. The database incorporates data from geological maps, sedimentological logs, data on microfacies and foraminifera obtained through optical and SEM microscopy, mineralogical (XRD), and geochemical (ICPMS) composition, cathodoluminescence analysis, and analysis of 28 isotopic values of carbon (13C/12C), oxygen (16O/18O), and strontium (87Sr/86Sr). Stone products were examined through a multilevel an approach using the same methods (step 1 ‒ macroscopic, step 2 ‒ microscopic, and step 3 ‒ geochemical analysis). 305 stone products were examined, 168 were sampled on previously damaged areas, and complete records were collected for 37 stone products. Analyses of the stratigraphic successions in the proposed quarry areas show that all formations contain macroscopically distinct lithotypes, mostly biogenic limestones, as well as characteristic microfacies types that allow sufficient determination of provenance. Where facies distinction between stone products was insufficient, we relied on different foraminifer assemblages. When even foraminifera were absent, discrimination was based on geochemical and isotopic data. Using the multilevel approach, we were able to determine the provenance on macro and micro step for 49.5 % of the stone products studied. All the studied stone products with complete records of the methodology were traced back to a specific stratigraphic formation (or member) based on geochemical composition (specifically SiO2, Al2O3, Fe2O3 and MnO content), and measurements of carbon and strontium isotopes. Using the multimethod database, we are able to distinguish all limestone types that outcrop on the previously proposed quarry areas. Furthermore antique stone products can be placed in each. In addition, a previously unknown type of limestone used in the production of stone products in Colonia Iulia Emona has been identified. It originates from the deeper marine Lower Cretaceous limestone.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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