ALBERT

Description: 〈p〉Publication date: Available online 26 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms〈/p〉 〈p〉Author(s): Danuta Michalska〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The methods of production of anthropogenic carbonaceous mortars makes them a valuable material for radiocarbon dating. The probability of successful application of 〈sup〉14〈/sup〉C dating to mortars is related to the sample composition, not just the binder and added admixtures, but also the type, amount, and preservation state of the aggregate. The influence of different mortar components and applied pretreatments on dating results were demonstrated by 〈sup〉14〈/sup〉C measurements on samples for which the preparation technique was either chosen on the basis of their composition or applied in an arbitrary and pre-defined manner.〈/p〉 〈p〉Mortars from 7 different locations are presented here (37 samples analysed and compared). The preparation procedures utilize mechanical and chemical selection of material for 〈sup〉14〈/sup〉C measurements; collection of CO〈sub〉2〈/sub〉 at different times, during decomposition in orthophosphoric acid, is applied to carbonates obtained, for example, from grain size selection or from different portions of forced suspensions. An important point is that aside from detailed analysis and applied preparation, the sampling of a mortar from a well-defined position, not suspected of any reworking, is crucial. In presenting 〈sup〉14〈/sup〉C measurement results from different types of mortars and pretreatments, this paper illustrates the development of preparation methods over the years and the impact of their application on samples with different compositions.〈/p〉 〈/div〉 〈/div〉