Accurate radiocarbon (14C) dating of lime mortars requires a thorough mineralogical characterization of binders in order to verify the presence of carbon-bearing contaminants. In the last 20 years, cathodoluminescence (CL) has been widely used for the identification of geologic calcium carbonate (CaCO3) aggregates and unreacted lime lumps within the particle size fraction selected for carbon recovery. These components are major sources of older and younger carbon, respectively, and should be removed to obtain accurate age determinations. More recently, laser-induced fluorescence (LIF) has provided another means of investigating the preservation state and composition of CaCO3 binders. Considered the growing interest of the mortar dating community in the latest advancements of these analytical methods, here we review the principles of CL and LIF of CaCO3, their instrument setup, and their application to the characterization of ancient lime mortars used for 14C dating. In addition, we provide examples of SEM-CL and LIF analyses using high-resolution instrumentation, we discuss current issues and propose future lines of research.

中文翻译：

---

碳酸钙的阴极发光和激光诱导荧光：古代石灰砂浆的放射性碳测年筛选方法综述

准确的放射性碳 (14C) 石灰砂浆的年代测定需要对粘合剂进行彻底的矿物学表征，以验证是否存在含碳污染物。在过去的 20 年里，阴极发光（CL）已被广泛用于地质碳酸钙（CaCO3) 选择用于碳回收的粒度部分内的聚集体和未反应的石灰块。这些成分分别是较老和较年轻碳的主要来源，应去除这些成分以获得准确的年龄测定。最近，激光诱导荧光 (LIF) 提供了另一种研究 CaCO 保存状态和组成的方法3粘合剂。考虑到砂浆测年界对这些分析方法的最新进展越来越感兴趣，在这里我们回顾一下 CaCO 的 CL 和 LIF 的原理3，他们的仪器设置，以及他们在古代石灰砂浆表征中的应用14C约会。此外，我们提供了使用高分辨率仪器进行 SEM-CL 和 LIF 分析的示例，我们讨论了当前问题并提出了未来的研究方向。