Prompt γ-ray spectra sometimes contain hundreds of characteristic peaks, and the masses of the sample components can be determined from dozens of γ-ray peak areas, some of which are affected by spectral interferences. Reliable qualitative and quantitative analyses can only be performed by using a precisely calibrated detector system, an accurate spectroscopic data library, high-quality spectroscopy software, and a sophisticated method to convert raw data into chemical composition. This article describes the steps of the chemical analysis with prompt γ activation analysis (PGAA). A complete data reduction method has been constructed that handles the large number of spectral peaks using statistical procedures, identifies the chemical components based on statistical criteria, and determines the sample composition with a least-squares fit of the masses calculated from the individual peaks. The calculation of the uncertainties as well as the detection and analytical limits are discussed in detail. The validati...

Determining Elemental Composition Using Prompt γ Activation Analysis

5,000 years old Egyptian iron beads made from hammered meteoritic iron

Recently, several archaeometrical projects have been started on the prehistoric collection of the Hungarian National Museum. Among the analytical methods applied, non-destructive prompt gamma activation analysis has a special importance. We have also tested the potential of this method on chipped stone tools, with the aim of determining their exact provenance. On the basis of major and trace element components, characterizations of stone tools and their raw materials-silicites (flint, chert, radiolarite and hornstone) as well as volcanites (felsitic porphyry and obsidian)-were performed. We discuss some important results concerning each group, as case studies. Compiling the data set of different PGAA analysis series, compositions of 110 samples are reported, including 76 archaeological pieces. In the future, we plan to extend the number of investigated objects in each class.

Cold neutron prompt gamma activation analysis - A non-destructive method for characterization of high silica content chipped stone tools and raw materials

This paper thematically characterizes a large body of recent obsidian sourcing discourse as a means of highlighting the current place of obsidian provenance studies in larger archaeological discourse. It is shown that the field of obsidian sourcing is flourishing, with a clear upward trend in the number of published studies in the past decade. This paper further argues that sourcing is a means to an end, a way to determine where artefacts originate, and thus a means of addressing broader archaeological problems. Through this contextual framework, obsidian sourcing studies—and indeed all provenance studies—are seen as relevant because they transcend the increasingly specialized world of archaeological discourse.

An assessment of the current applications and future directions of obsidian sourcing studies in archaeological research

The physical requirements of stone tools tend to prescribe the choice of rocks for their production. Hardness, roughness and impact toughness dictate the ease of knapping as well as the durability of flaked tools, and these rock properties can be measured by mechanical tests described here. Geochemical and petrographic analyses of archaeological and geological samples can also characterise rocks and, under certain circumstances, they enable rock sources to be traced. Examples of how this can be achieved are provided from sites around the world. At Sibudu, KwaZulu-Natal, locally available dolerite and hornfels are the most common rock types employed to make flaked tools. Unfortunately, neither rock lends itself to being sourced, but mechanical tests demonstrate that these rocks have both desirable and undesirable properties for stone-tool manufacture and use. Coarse-grained (rough) dolerite is difficult to knap, but it ensures durable tool edges, whereas fine-grained hornfels is relatively easy to knap, but the sharp edges on its products are sometimes fragile, require resharpening, and have a tendency to break. Dolerite was thus more suited to tool manufacture than we initially realised.

A review of rock studies for archaeologists, and an analysis of dolerite and hornfels from the Sibudu area, KwaZulu-Natal

Szeletian felsitic porphyry: non-destructive analysis of a classical palaeolithic raw material

Recently, several archaeometrical projects were started on the prehistoric collection of the Hungarian National Museum. Among the analytical methods applied, non-destructive prompt gamma activation analysis (PGAA) has a special importance. Based on major-and trace components, characterization of stone tools and their raw materials were performed. Until now, 160 pieces from Carpathian Basin and from the surrounding area (Romania, Croatia, Ukraine, Poland and the Mediterranean region) have been analyzed, including both archaeological and geological pieces. Obsidian and Szeletian felsitic porphyry objects adequately separable with PGAA. Identification of high silica silex categories, however, is much more difficult.

András Markó

Papers

Cold neutron prompt gamma activation analysis - A non-destructive method for characterization of high silica content chipped stone tools and raw materials

Szeletian felsitic porphyry: non-destructive analysis of a classical palaeolithic raw material

Prompt gamma activation analysis for non-destructive characterization of chipped stone tools and raw materials

The influence of paleogeomorphology on the stable isotope signals of paleosols

Different paleoenvironments of Late Pleistocene age identified in Verőce outcrop, Hungary: Preliminary results