Iron Forms Fe(II) and Fe(III) Determination in Pre-Roman Iron Age Archaeological Pottery as a New Tool in Archaeometry

This article presents studies on iron speciation in the pottery obtained from archaeological sites. The determination of iron forms Fe(II) and Fe(III) has been provided by a very simple test that is available for routine analysis involving the technique of molecular absorption spectrophotometry (UV–Vis) in the acid leachable fraction of pottery. The elemental composition of the acid leachable fraction has been determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Additionally, the total concentration of the selected elements has been determined by X-ray fluorescence spectrometry with energy dispersion (EDXRF). The results of the iron forms’ determinations in archaeological pottery samples have been applied in the archaeometric studies on the potential recognition of the pottery production technology, definitely going beyond the traditional analysis of the pottery colour.

An Open System for Collection and Automatic Recognition of Pottery through Neural Network Algorithms

In the last ten years, artificial intelligence (AI) techniques have been applied in archaeology. The ArchAIDE project realised an AI-based application to recognise archaeological pottery. Pottery is of paramount importance for understanding archaeological contexts. However, recognition of ceramics is still a manual, time-consuming activity, reliant on analogue catalogues. The project developed two complementary machine-learning tools to propose identifications based on images captured on-site, for optimising and economising this process, while retaining key decision points necessary to create trusted results. One method relies on the shape of a potsherd; the other is based on decorative features. For the shape-based recognition, a novel deep-learning architecture was employed, integrating shape information from points along the inner and outer profile of a sherd. The decoration classifier is based on relatively standard architectures used in image recognition. In both cases, training the algorithms meant facing challenges related to real-world archaeological data: the scarcity of labelled data; extreme imbalance between instances of different categories; and the need to take note of minute differentiating features. Finally, the creation of a desktop and mobile application that integrates the AI classifiers provides an easy-to-use interface for pottery classification and storing pottery data.

A Semi-Automatic Reconstruction of Archaeological Pottery Fragments from 2D Images Using Wavelet Transformation

The problem of matching fragments of three-dimensional (3D) objects has gained increasing attention, and several approaches have been developed to solve this problem. To date, however, to the best knowledge of the authors, there is no computer-based method supporting archaeologists in this activity. For this purpose, in this paper, a semi-automatic approach is proposed for the reconstruction of archaeological pottery fragments based on two-dimensional (2D) images. Firstly, the method, considering the curves as features, involves the extraction of edge curves by applying the Canny filter algorithm to the fragments’ image. Next, the wavelet transformation method is used to fit the edge curves and obtain the approximation coefficients. Then, the correlation coefficients between fragments are computed and the matching of fragments is done by comparing their values. The proposed approach is tested on some real cases. The results of the experimentation show, if compared with the state-of-the-art, that the method seems to be efficient and accurate in the reconstruction of pottery from 2D images of their fragments.

ABOUT A TECHNIQUE OF DIMINISHING NEGATIVE EFFECT OF LIMESTONE TEMPER IN POTTERY

Статья посвящена исследованию приема закаливания глиняных сосудов, известного по этнографическим данным. Для закаливания изделия, достигшие температуры 800–850 °С, вынимались из обжигательного устройства и сразу помещались в емкость с водой. Считается, что в результате этой операции сосуды приобретали дополнительную прочность. При закаливании керамики с примесью известняка происходит частичное вымывание СаО, который образуется во время обжига. За счет этого уменьшается вредное воздействие примеси известняка, ведущее к образованию «выколов» на стенках сосуда. С помощью серии экспериментов автор исследовал возможности фиксации случаев использования приема закаливания по археологической керамике с примесью известняка. Выявлены признаки, возникающие при этом в изломах и на поверхностях керамических образцов. Подтверждено ослабление разрушающего действия карбонатов в результате использования приема закаливания сосудов, особенно при размере частиц известняка менее 2,0 мм. Тем не менее однозначно связывать выявленные признаки только с приемом закаливания пока преждевременно. Institute of Archaeology of Russian Academy of Sciences, Moscow, Russia The article is dedicated to a technique of scalding clay vessels known from ethnographical data. To this end vessels after reaching the temperature of glowing red heat were taken out of firing device and immediately placed in a recipient with cold water. As a result of this procedure the vessels gained extra hardness. In the process of scalding pottery with limestone temper CaO which forms during the firing is partly removed. This diminishes the negative effect of limestone temper which leads to formation of “chips” on the vessel walls. The author researches through a series of experiments the possibility of detecting cases in which the technique of scalding archaeological pottery with limestone temper is used. The signs have been detected which appear in the process of scalding in fractures and on the surface of pottery samples. The diminishing destructive effect of carbonates as a result of pottery scalding especially when particles of limestone were smaller than 2mm has been confirmed. Nevertheless it’s premature to associate the detected signs only with the technique of scalding.