Katalin T. Biró

Imaging of cultural heritage objects using neutron resonances

Neutron resonances are the signature signals of a non-destructive elemental and isotopic analysis technique in archaeological sciences. We report on Neutron Resonance Transmission Analysis and its capabilities as a bulk elemental imaging technique to test the homogeneity of samples and to localize elements of interest in archaeological samples and museum objects. A high neutron flux is required for imaging in order to achieve reasonable spatial resolution and to keep measurement times within realistic limits. A modular system for neutron resonance transmission analysis has been designed and installed at the INES beamline of the ISIS spallation neutron source as a part of the ANCIENT CHARM project. The main component is a neutron position sensitive transmission detector which is based on a 10 × 10 array of 6Li-glass crystals mounted on a pitch of 2.5 mm, resulting in a 25 × 25 mm2 active area. Transmission spectra are obtained by a measurement of the flight time of epithermal neutrons passing through an object. The transmission dips observed in a time-of-flight spectrum can be used to identify and quantify specific nuclides. In this paper the technique is described together with the data reduction and analysis procedures. In addition, preliminary results obtained from measurements on cultural heritage samples are discussed.

Neutron resonance transmission imaging for 3D elemental mapping at the ISIS spallation neutron source

We demonstrate for the first time the viability of a three-dimensional (3D) elemental imaging technique based on Neutron Resonance Transmission Imaging (NRTI), which is a neutron technique based on the presence of a resonance structure in the neutron-induced reaction cross sections. These resonances allow the identification of elements and isotopes within an object in a non-destructive manner. A dedicated set-up on the INES (Italian Neutron Experimental Station) beamline of the ISIS spallation neutron source was employed for the experiments. An early mediaeval disc fibula from the Hungarian National Museum in Budapest was used for our demonstration. The methodology and analysis procedures are described and the results obtained from the reconstruction of the 3D NRTI elemental image of the ancient object are compared with the results obtained from other neutron-based 3D imaging techniques.

The ANCIENT CHARM project at FRM II: three-dimensional elemental mapping by prompt gamma activation imaging and neutron tomography

The aim of the EU FP6-funded ANCIENT CHARM project has been the development of new, and the integration of existing element-sensitive imaging methods utilizing neutrons. We present here the methodology and the first implementation of 3D elemental mapping at the Prompt Gamma Activation Analysis instrument of the research reactor FRM II, in order to determine spatially resolved elemental abundances in samples. After the design, optimization, and characterization of the new setup, measurements were successfully completed on archaeological objects of historical significance from the collection of the Hungarian National Museum.

Discrimination of prehistoric polished stone tools from Hungary with non-destructive chemical Prompt Gamma Activation Analyses (PGAA)

The determination of the geological provenance of the different rocks employed for the manufacture of prehistoric stone tools is useful from both historical and archaeological points of views, to indicate precise directions of cultural interactions. Prehistoric polished stone tools with fine to very fine grained texture may show striking similarities in their macroscopic appearance by texture and colour. Therefore, it is very difficult to distinguish the different rock types by naked eye. Prompt Gamma Activation Analysis (PGAA) is one of the powerful, absolutely non-destructive bulk chemical methods for the analysis of archaeological materials. As regards polished stone tools, PGAA measures all major elements and few trace elements. We analyzed 189 polished stone tools from different collections and localities of Hungary, and 42 geological samples from potential raw material sources. To control the method, several broken pieces were studied also by destructive methods, mainly thin-section petrography. Our results are: 1. we obtained chemical composition of the analyzed artefacts, 2. we created an initial database of PGAA results of the most important raw materials of polished stone tools occurring in Hungary, 3. we explored the potentials and limitations of PGAA in the determination of the raw materials used for the polished stone tools. As a result, several different raw material groups (basalt-dolerite-metadolerite, greenschist-contact metabasite-amphibolite, blueschist, hornfels, “white stone”, ultramafic rocks and intermediate volcanic rocks) could be distinguished. Moreover, different rock types were recognized within each group ( e.g ., greenschist-contact metabasite and basalt-dolerite). Macroscopic description combined with PGAA will help to determine raw material types of polished stone tools. However, in some cases other methods are also necessary to achieve precise determination.

Investigation of incrusted pottery found in the territory of Hungary by micro-PIXE method

Abstract Incrusted pottery samples from the territory of Hungary were analyzed by micro-PIXE technique. Measurements were executed on the front and back side of the samples and inside the incrustations too. We succeeded to group the pottery from different regions and periods by the composition of the ornament. It was concluded that the elemental composition of the ornament may be characteristic to the provenance of the pottery. In case of samples from Vors-Mariaasszonysziget the presence of a kind of grit in the incrustations with high calcium and phosphorus content was established. The material of the grit is presumably bone. Samples from other archaeological localities can be described by incrustations with different compositions. Incrustations in the samples from Balatonfuzo are presumably composed of limestone (CaCO 3 ), from Baradla cave (Aggtelek) probably of white clay paste (kaolinite). It was also concluded that the red color of the ornaments of some sample from Baradla cave is caused by hematite.

Geochemical analysis of radiolarite samples from the Carpathian basin

Abstract A very important raw material of the prehistoric age, radiolarite was investigated in this work. Samples from geological and archaeological sites of the Carpathian basin, Greece and Austria were analyzed by ion beam methods, namely proton-induced gamma-ray emission (PIGE) and proton-induced X-ray emission (PIXE) techniques. Our aim was to study to what extent we are able to classify the specimens with various macroscopical features and different source areas. In order to answer this question, a cluster analysis was carried out on the concentration data set deduced from the analysis. Correlations between the elemental compositions and the source regions are established.

Contribution to the cognizance of raw materials and raw material regions of the Transcarpathian Palaeolithic

On the territory Transcarpathian Ukraine, about 100 Palaeolithic localities are known up to our days. Most of them are surface finds. In spite of the rich archaeological heritage, the elaboration of the material, especially its petroarchaeological evaluation supported by professional scientific analytical methods, is in the initial phase as yet. The aim of the present study is to supply information on the lithic raw materials of the Palaeolithic settlements in Transcarpathian Ukraine, the detailed survey and description of the primary raw materials, their identification, description and terminology, as well as the outlining of the local raw material provinces and study of the distribution of the raw materials on archaeological sites. In the archaeological literature of Transcarpathian Ukraine, lithic raw materials are still described under incorrect petrographical terms. For example, for the raw material of Korolevo Palaeolithic site is, correctly speaking, hyaline dacite, and the “flints” of Beregovo reg...

Ceramics, Marbles and Stones in the Light of Neutrons: Characterization by Various Neutron Methods

In this chapter we give a brief overview of neutron based analytical investigations applied to study archaeological ceramics, and different types of stones. Since the vast majority of archaeological objects are made of ceramics and various stones—all are of geological origin—, one of the key objectives of these studies to determine the origin of raw material. This research is called provenance research, and a wide range of neutron based methods are applicable in it. Following a very basic, user-oriented description of the methods, we introduce examples from our everyday practice. The examples are about provenance of prehistoric stone tools, about the sources of 4th–3rd c. B.C. millennium limestone idols found in the South of Portugal, as well as about the characterization of 15th–16th c. A.D. Inka pottery. A very unique application of combined neutron techniques was aimed to determine the inner content of an Eighteenth Dynasty Egyptian sealed vessel. In addition, investigations of samples from different epochs and characterization of marbles are presented.

Archaeometric Processing of Polished Stone Artefacts from the Ebenhöch Collection (Hungarian National Museum, Budapest, Hungary)

The petrological processing of archaeological polished stone artefacts from the Carpathian Basin has started to develop only in the last decades. This work benefited much from the systematic elaboration of historical collections from the nineteenth century. One of the most significant collections of this type was donated to the Hungarian National Museum by Ferencz Ebenhoch, abbot-prebend in Győr. The collection is extremely rich in polished stone artefacts, and unique not only because of its quantity (nearly 700 pieces), but also due to the beauty of the tools. To date, only a preliminary macroscopic petrographic identification had been carried out on the items. The aim of the present investigations was to identify and describe the raw material of the artefacts, and, if possible, determine their provenance.

Analysis of prehistoric pottery finds from the Balaton region, Hungary

Abstract An application of micro-PIXE technique for the analysis of pottery fragments from an intensively studied Hungarian archaeological site, Vors-Mariaasszonysziget, is detailed in this work. The fragments originated from different closed archaeological units of various ages. The correctness of our hypothesis, i.e. the correlation between the bulk and microscopic contents of the samples and the raw material source and/or manufacturing technique (in this way the age) for the vessels is discussed.