1 451198 HERCULES Laboratory, University of Évora, Évora, Portugal.
2 CIDEHUS, University of Évora, Évora, Portugal.
Appl Spectrosc. 2018 Jan;72(1):17-27. doi: 10.1177/0003702817721934. Epub 2017 Nov 20.
This work is part of a broader research line that aims to develop and implement a nondestructive methodology for the chemical characterization of archaeological metals based on a protocol that combines energy dispersive X-ray fluorescence spectrometry (ED-XRF) with a Monte Carlo (MC) simulation algorithm. In this paper, the ED-XRF-MC protocol has been applied to estimate the chemical composition of a selected group of 26 copper-based artifacts and fragments recovered at Perdigões, one of the larger Chalcolithic sites of southwest Iberia. All the analyzed artifacts have a multilayered structure composed of the alloy substrate and of a superficial layer common in each metal buried for hundreds of years and consisting of the patina mixed with soil. Due to the difficulty in determining the quantitative composition of these alloys in the presence of this complex patina/encrustation layer, the spectrometric protocol applied in this paper allows to simulate and to determine the composition of the bulk alloy without any prior removal of the overlying corrosion patina layer and soil-derived crust, even in the presence of rough and irregular surfaces, thus preserving the physical integrity of the artifacts. The overall results obtained with the ED-XRF-MC protocol indicates that the artifacts from Perdigões are almost pure coppers with a low amount of arsenic (<3.0 wt%) and reduced concentration of elements such as Pb, Bi, and Sb, in agreement with the third millennium metallurgy known in southwestern Iberia. Also based on previously theoretical-experimental studies, the data presented in this paper show how the applied analytical methodology can be a fast and completely nondestructive analytical tool reliable for routine and large-scale chemical analysis of archaeological metals, thus representing a major advance to be broadly applied within the field of cultural heritage studies.
这项工作是更广泛研究项目的一部分，旨在开发和实施一种基于能量色散 X 射线荧光光谱法（ED-XRF）与蒙特卡罗（MC）模拟算法相结合的协议，对考古金属进行化学特征分析的非破坏性方法。在本文中，ED-XRF-MC 协议已应用于估算在伊比利亚西南部较大的铜石器时代遗址之一的佩德里格尼斯（Perdigões）出土的 26 件铜基文物和碎片的化学成分。所有分析的文物都具有多层结构，由合金基底和在每个金属埋藏数百年后形成的共同的表面层组成，该表面层由与土壤混合的铜锈组成。由于在存在这种复杂的铜锈/结壳层的情况下，难以确定这些合金的定量组成，因此本文中应用的光谱协议允许模拟和确定块状合金的组成，而无需预先去除覆盖的腐蚀铜锈层和土壤衍生的外壳，即使在存在粗糙和不规则表面的情况下也是如此，从而保持文物的物理完整性。ED-XRF-MC 协议获得的总体结果表明，佩德里格尼斯的文物几乎是纯铜，仅含有少量砷（<3.0wt%），并且 Pb、Bi 和 Sb 等元素的浓度降低，这与伊比利亚西南部已知的第三个千年冶金术一致。同样基于先前的理论-实验研究，本文中提出的数据表明，所应用的分析方法可以是一种快速且完全非破坏性的分析工具，可用于考古金属的常规和大规模化学分析，从而在文化遗产研究领域得到广泛应用。
