The absolute dating of mortar by accelerator mass spectrometry (AMS) has been the subject of renewed interest for several years. International intercomparison campaigns, called MODIS (MOrtar Dating Intercomparison Study), have been carried out. The first MODIS-1 campaign highlighted limitations in mortar dating, due to the similarity between the primary material to be dated (binder) and the contaminant (exogenous CaCO3). Methods have since emerged to overcome this problem and the need for a good preliminary characterization has been proven. The Laboratoire de Mesure du Carbone 14 (LMC14) took part in the second intercomparison campaign, MODIS2, by applying thermal decomposition increments to distinguish the carbonated binder, the organic matter contaminants (late in formation pyrogenic carbonate, LDH) and limestone. The LMC14 results on MODIS2 are quite conclusive on “pure” re-carbonated lime mortar binders containing little contaminant geological limestone but show their weaknesses for mortars heavily contaminated in Dolomites, which are difficult to discern from the binder. Recommendations for users of radiocarbon (14C) dating on mortar-based materials are made in the conclusion.

中文翻译：

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在 LMC14 上制定了用于文化遗产材料：历史砂浆测年的 14C 协议。参与 MODIS 国际比对活动

多年来，通过加速器质谱法 (AMS) 对砂浆进行绝对测年一直是人们重新关注的话题。称为 MODIS（MOrtar 约会比对研究）的国际比对活动已经开展。第一个 MODIS-1 活动强调了砂浆测年的局限性，因为要测年的主要材料（粘合剂）和污染物（外源 CaCO3）。此后出现了克服这个问题的方法，并且已经证明需要良好的初步表征。Laboratoire de Mesure du Carbone 14 (LMC14) 参加了第二次比对活动 MODIS2，通过应用热分解增量来区分碳酸化粘合剂、有机质污染物（地层后期热解碳酸盐，LDH）和石灰石。MODIS2 上的 LMC14 结果对于含有少量污染地质石灰石的“纯”再碳酸化石灰砂浆粘结剂非常具有决定性，但显示出它们对于白云岩中严重污染的砂浆的弱点，很难从粘结剂中辨别出来。对放射性碳用户的建议（14C)结论中对砂浆基材料进行了测年。