Stable carbon and oxygen isotope investigation in historical lime mortar and plaster – Results from field and experimental study

摘要: Abstract Lime mortar and plaster were sampled from Roman, medieval early modern buildings in Styria. The historical lime consist of calcite formed the matrix during setting various aggregates. stable C O isotopic composition was analyzed to get knowledge about environmental conditions formation. δ 13 18 values range −31 0‰ −26 −3‰(VPDB), respectively. Obviously, such a isotope does not represent local natural limestone assumed be used for producing plaster. In an ideal case, is isotopically lighter exterior vs. interior layer according relationship  = 0.61 ·   − 3.3 (VPDB). Calcite precipitation by uptake gaseous CO 2 into alkaline Ca(OH) solutions shows similar relationship,  = 0.67 ·   − 6.4 Both relationships indicate that C/ 12 O/ 16 reflect behaviour Initially, atmosphere fixed as calcite, which accompanied kinetic fractionation mostly due hydroxylation (  ≈  −25‰  ≈ −20‰). As formation continued remaining subsequently enriched causing later heavier along path matrix. Deviations may evolution H O, e.g. evaporation, source , biogenic origin, relicts limestone, secondary effects, recrystallization calcite. results field experimental study suggest can overall proxies decipher origin carbonate ancient recent Moreover, these select 14 dating.