Panel 11.4 – Geochemistry and Economic History: Approaching Ceramic Productions in Ancient Times with Portable Ed-XRF


Organiser/Chair:

  • Lars Heinze (University of Cologne)
  • Markus Helfert (University of Frankfurt)

Panel abstract

As archaeometric services become more affordable and prices for instruments are decreasing, a wide range of techniques and methods (i. e. geophysical prospections, 3D-laser scanner, aerial photography) gets more frequently implemented into new archaeological projects. Moreover, with easy-to-use interfaces and Archaeometry becoming a regular field of study at universities, many of these approaches are now applied by archaeologists themselves on a regular basis, with fewer “experts” accompanying, guiding and controlling these projects.

This panel aims to explore how this trend has impacted geochemical analysis of pottery assemblages over the recent years. This field in particular was revolutionized over the last decade by the introduction of portable X-ray analyzers finally becoming affordable for research institutions and even larger university projects. These devices not only promise full flexibility for chemical measurements ('handheld'), but also instant results without taking and processing samples from the objects under research ('non-destructive'). However, after the initial euphoria, critique arose about how or if at all to use the devices as a new standard for the study of ancient ceramics provenances.

The presentations within this panel therefore will deliver an overview over the various ways projects have successfully implemented portable XRF devices into their pottery studies. Lecturers are encouraged to not only focus on results for the production and distribution of the studied pottery, but also to critically review their methodology and to demonstrate how they have learned to handle and overcome some of the intrinsic downsides of these portable analyzers. Furthermore, lecturers are welcome to attest ways of combining portable XRF measurements with other, more conventional analytical techniques, such as ceramic petrography, stationary geochemistry (WD-XRF, NAA) or others.

Paper abstracts

1. Elena Cuijpers (University of Bonn)

The production and distribution of tiles in Classical Chalkidiki: a geochemical analysis of clay samples, excavation and survey material with portable XRF
In my presentation I will discuss the results of a geochemical analysis of classical tiles and clay samples from Chalkidiki (Northern Greece) that will be carried out with a portable XRF device in the coming months. The analysis is part of my PhD dissertation at the University of Bonn that will also include ceramic petrography. The majority of the dataset for this analysis consists of tiles recovered via excavations and surface survey (led by the Olynthos Project, 2014-present) in and around the ancient settlement of Olynthos. While much progress has been made in reconstructing domestic life at this settlement, there are many unanswered questions about the ceramic economy of the city. Additionally, tiles from other classical settlements in Chalkidiki are being incorporated to provide a regional perspective on this topic. The first aim is to characterize and distinguish ceramic tile fabrics based on their chemical composition and to compare the results to the macroscopically identified fabric groups. A second goal is to compare the fabric groups to the (fired) clay samples collected in the region to investigate possible provenances of the material. Overall, this analysis could provide insights into clay sourcing, tile production and distribution in Olynthos and the surrounding region. While discussing the results and observations I will critically review the application of a portable XRF device to this ceramic study.

 

2. Silvia Amicone and Christoph Berthold (University of Tübingen) / Lars Heinze (University of Cologne) / Claudia Lambrugo (University of Milan)

Pottery Consumption in the Chora of Gela: The Case of the 'Fattorina Officina' of Manfria
This research focuses on a 4th century BC rural complex in Manfria, a site situated 12 km west of the Greek colony of Gela (CL) in Sicily. Excavated in the 1950s but still largely unpublished, the so-called Manfria Farm yielded a rich archaeological assemblage that can shed new light on human population in central 4th-century BC Sicily following a phase of intense social disruption and warfare that resulted from the Carthaginian invasion.
After a period of silence regarding the territory of Gela, crucial new research conducted over the last few years has provided new stimuli for the study of the chora of this important Greek colony. Despite this new interest, there is still a lack of a systematic study in the relation to pottery production and circulation within the chora with the application of archaeometric methods. And while the material from the colony of Gela was partially using different analytical methods in order to characterise its composition and technology, the pottery from the chora remained mostly studied only from a typological point of view.
This work for the first time combines different analytical methods, including p-XRF, petrographic analysis and X-ray diffraction, to study the vast pottery from the important assemblage of Manfria. The results are expected to not only elucidate on different aspects of pottery technology and circulation in the chora of Gela, but also to constitute a reference study for the territory of this important colony.

 

3. Anno Hein (N.C.S.R. “Demokritos”) / Agata Dobosz (Jagiellonian University) / Vassilis Kilikoglou (N.C.S.R. “Demokritos”)

Portable ED-XRF as tool for defining the sampling strategy – Case study of a Hellenistic amphora assemblage from Paphos (Cyprus)
Provenance studies of archaeological ceramics based on their elemental composition provide important information about the organization of production and the distribution of the ceramic vessels or the commodities that they contained. Basic assumption is that the elemental composition of ceramics from a specific workshop or production area can be distinguished from other ceramic production groups mainly because of the use of geochemically different clays. In some cases, however, the compositional differences between production groups are quite small. Thus, commonly laboratory methods with high performance, in terms of precision and accuracy, are preferred for analyzing archaeological ceramics, such as neutron activation analysis (NAA) or wavelength dispersive X-ray fluorescence (WDXRF). Handheld portable energy dispersive XRF systems (pEDXRF), although increasingly used in the last years, present a less sufficient analytical performance, which might obscure compositional differences. Nevertheless, due to the potential of fast and non-invasive measurements, considerably larger numbers of samples can be analyzed. Taking this in account, pEDXRF can be applied for an initial analytical survey of a large ceramic assemblage as basis for an efficient sample selection for laboratory analysis, avoiding for example redundant measurements. A case study will be presented of pEDXRF of c. 300 fragments of Hellenistic amphorae mainly from the excavation of the Agora in Paphos (Cyprus). The assemblage analyzed comprised imported amphorae from the entire Eastern Mediterranean region. The pEDXRF results were evaluated by grouping on the basis of elements which reflect mainly the type of raw materials used in pottery production. Out of these groups, 97 fragments were selected, from which eventually samples for NAA were taken for provenance study based on trace element compositions.

 

4. Markus Helfert (Goethe-Universität Frankfurt am Main)

Discovering ceramic production and consumption at Olbia Pontike in archaic and classical time – Application of portable ED-XRF and laboratory INAA for Greek Grey Ware
Ancient Olbia is one of the cities founded in the northern Black Sea area during the so-called Great Greek Colonization (8th-6th century BC). In its urban core area, field research has been carried out for several decades. In contrast very few is known about the suburban area, so that a new interdisciplinary German-Ukrainian research project under direction of J. Fornasier and A. Buiskich is carried out to investigate the settlement structure there. Thanks to the support of the Fritz Thyssen Foundation, the project was able to conduct geochemical analysis of ceramics from Olbia and the nearby Berezan settlement in a pilot study in 2015/16. By means of the P-ED-XRF 120 samples of the so-called “Grey Ware” from closed findings were analyzed for their “fingerprints” to find out characteristic groups. In a second step a selection of 40 samples were additionally analyzed by H. Mommsen at the Rheinische Friedrich-Wilhelms-Universität Bonn by instrumental neutron activation analysis to compare the recognized groups with references in the Bonn ceramic database. The approach known as the Frankfurt concept, which has been evaluated at the Goethe University and successfully tested and optimized over several years, combines the advantages of portable and laboratory methods to get the possibility to detect and evaluate larger ceramic sample series geochemically. The paper will present the method and results of the pilot and a following project in 2016/17.

 

5. Lars Heinze and Rabea Reimann (University of Cologne)

CeramEgypt: Pottery production and consumption in Hellenistic and Roman Egypt
About 20 years ago, Morgenstein und Redmount (1996, 76) stated that there is “a general paucity (…) of geochemical information for Egyptian ceramics, both spatially and through time”. The authors later took upon themselves to change this situation, partially with stationary machines but also via portable ED-XRF (Morgenstein – Redmount 2005; Emery – Morgenstein 2007). However, theirs and the projects of others who employed portable XRF devices in Egypt were usually limited to certain locations and never aimed at comparing data on a supra-regional level.
The aim of the French-German project 'CeramEgypt' instead is to sample and investigate pottery spanning from Hellenistic to Roman times and to cover the whole of ancient Egypt, while focusing on pottery produced in Egypt itself. For this, multiple portable XRF devices (Niton XL3t) are employed that operate with the same calibration and use the same measurement protocols.
The presentation will focus on the methods that are used to collect, calibrate and further process the geochemical information. It will also show the multi-leveled way in which the projects integrates the vast pXRF data with the archaeological information and, as a first pilot project, a limited amount of ceramic thin-sections. Based on this, first results covering multiple sites in Egypt will be presented and discussed.