One approach undertaken in the CoFIPoMS project was to study pottery sherds from the early Roman period in Malta that have been interpreted as locally produced. There are several aims to the study:
A Masters (by research) dissertation is focusing on the pottery analysis component of the project, studying the fabric of Early Roman period bowls, plates and cooking vessels from Malta (Richard-Trémeau, in progress). The dissertation aims at creating a fabric classification combining macroscopic observation, microscopy, polarised light microscopy and chemical characterisation. Technological processes (material processing, manufacturing, firing), and their implications, as well as possible raw material provenance, are considered.
An undergraduate dissertation (Humann 2022) has looked at a small sample set of handmade vessels using SEM-EDS. The idea was to look at the composition of sherd inclusions and compare the classification performed with microscopy / polarised light microscopy with a classification performed based on chemical characterisation.
Projects:
The pottery sherds were selected from two archaeological sites, the Żejtun Villa and the Punic-Roman sanctuary of Tas-Silġ. Both of these sites are situated close to Marsaxlokk Bay. These sites are multi-period sites and the study focuses on assemblages from secure contexts dated from the second to first century BCE.
The sanctuary of Tas-Silġ is situated close to Marsaxlokk Bay and has been widely excavated until 2005. It had first been excavated by the Italian Mission from 1963 to 1970. A temple dedicated to the Phoenician goddess Astarte was built above earlier religious buildings in the Late Republican period (2nd/1st century BCE) In 1996, the University of Malta carried out excavations in the area south of the sanctuary’s limits, where remains of a masonry platform and extensive midden deposits were located. The foundations of a large structure, , most probably a platform erected during the Early Roman expansion of the sanctuary, was excavated and dated to the 2nd/1st century BCE. The pottery sherds selected for the COFIPoMs project come from this period of restructuring of the site.
The Żejtun Villa, located over a kilometer from Tas-Silg, contains the remains of an ancient rural building with equipment associated with the pressing of olives to make olive oil. The earliest foundations of part of the building have been dated by pottery to the 5th/4th century BCE. Remains of rows of agricultural trenches indicate that the area occupying the site was cultivated by vines until they were abandoned and covered over by a larger Roman farm building partly dedicated to the pressing of olive oil, in the 2nd/1st century BCE. The remains visible today are mainly from this later time period.
The pottery assemblages from two stratigraphic units were chosen for each site. These assemblages still contained thousands of pottery fragments for the site of the sanctuary of Tas-Silġ and a further selection was performed, prioritising rims as these give archaeologists a good indication of the shape of the original vessels. These sherds had been looked at by pottery specialists for previous works published on the sites including the work by Sagona (2015) and Bechtold (2017).
More than 80 sherds were selected from among these assemblages. Most of the forms belong to bowls and plates, together with cooking vessels and a few handmade vessels.
References:
Bechtold, B. (2017) ‘The pottery from selected stratigraphic units (4th-1st cent. BCE)’, in Vella, N. C. et al., A view from the countryside: the nature of the Late Punic and Early Roman activity at the Zejtun villa site, Malta. Rivista di Studi Fenici, 45, pp. 122–143.
Sagona, C. (2015) ‘The pottery’, in Bonanno, A. and Vella, N.C. (eds) Tas-Silġ, Marsaxlokk (Malta): Archaeological Excavations Conducted by the University of Malta, 1996-2005. Leuven: Peeters, pp. 1–514.
The sherds were first described, photographed and drawn (for those which had not been drawn before). This retains a permanent record of the fragments for further studies, and is particularly important when destructive analysis is performed. This also gives the initial information on the manufacture of pottery, such as how the vessel was finished (surface treatment) or decorated, and clues on the techniques used in their manufacture, for example.
Fragments of 67 sherds were embedded in resin and ground flat for microscopy. Using a high-powered microscope, archaeologists are able to take a close look at the fabrics of the vessels, and determine the material’s “recipe” potters might have used. Other clues, such as an indication of the firing temperature, can also be obtained. One aim of the microscopic analysis is to create groups of sherds (fabric groups and subgroups) that are similar both in terms of inclusions (types and distribution), matrix and porosity.
Following this first study, a subset of these groups of sherds were sent for polarised light microscopy, which requires creating thin sections of the sherds. This techniques allows trained researchers to identify some of the minerals present within the pottery, investigate the composition of the pottery fragments as well as several technological processes (eg. firing regime).
In parallel, a sample set was analysed in a semi-quantitative way using X-Ray Fluorescence (XRF), which gives the elemental composition of each sample. The samples were compared across samples, but also with clays from the Maltese islands. To optimise the analysis, the samples are prepared by removing their surface (which could have a different composition), crushing them to a homogenous powder and drying them thoroughly.
The results of XRF were then analysed using statistical methods including Principal Component Analysis and hierarchical cluster analysis.
