Indagine archeometrica delle ceramiche rinvenute sul Timpone della Motta di Francavilla Marittima (CS)

Abstract

In this work, we focus on the archaeometric characterisation of some pottery remains dated to the 8th and early 7th centuries BC. The examined sherds come from the excavations carried out by the Groningen Institute of Archaeology (GIA) on the acropolis of the Timpone della Motta archaeological site, located near the well-known Greek colony of Sybaris (Calabria, southern Italy). The site of Timpone della Motta and the surrounding area is one of the key points for study of cultural and material development in southern Italy between 800 and 510 BC; the site is located, near the modern village of Francavilla Marittima (province of Cosenza, Calabria), 11 km inland from the sea and 12 km north of the Greek Apoikia of Sybaris. Here, traces of the first settlement date back to the Middle Bronze Age, but the site did not gain any substantial importance until the early 8th century BC, when it developed into a place of worship for the indigenous Oinotrians. Later, following the founding of the Achaean Apoikia of Sybaris, in the last quarter of the 8th century BC, the site became a mixed indigenous and Greek sanctuary. The ample and varied nature of contextual evidence from the site provides insights into the development of religious and mortuary practices, domestic life, and the manufacturing processes applied to pottery and other objects within the indigenous community (Jacobsen, 2007). The material culture found in the sanctuary on the top of Timpone della Motta is most interesting, since it includes large numbers of various pottery groups of Greek, regional and local origin which were in use in the sanctuary for more than two centuries. However, in order to evaluate the significance of the individual classes of pottery, their provenance needs to be better understood. A first step in this direction was to clarify which pottery classes were produced locally at Timpone della Motta. We focus here on five ceramic classes frequently found in the sanctuary: a) impasto pottery; b) matt-painted pottery; c) Oinotrian-Euboean style; d) colonial ware (hydriskai); e) Sub-Thapsos pottery. The impasto ceramic, from a functional point of view, in Southern Italy was used in the early Iron Age mainly for the production of tableware, fire ware and a series of common use containers. Following several decades of excavations and research in the Sibaritide area and in southern Italy, it seems clear a regional and interregional movement of impasto pottery. In the present work it was studied a group of impasto fragments in order to detect the possible presence of a differentiated production. The thirtyfive fragments represent all the various pastes that, macroscopically, appear to be the most common in the impasto ceramic from the Timpone della Motta. Indigenous matt-painted pottery was produced in several Southern Italian sites throughout the Iron Age. The vessels are either hand-made or formed on a slowly rotating device and decorated with indigenous mono- or bi-chrome motifs. The wide range of indigenous shapes demonstrates that this class of pottery was used as tableware and for household and storage purposes. Twentyfive fragments from two stylistic groups within the matt-painted samples were selected for analysis: i) Undulating Band Style, and ii) Fringe Style. Both groups are dated to the 8th century BC and their distribution is mostly limited to the Timpone della Motta area, and hence normally regarded as locally produced. Recent research has, however, documented a notably different group of Matt-Painted pottery on the Timpone della Motta, which display a high level of craftsmanship in being very thin-walled and decorated in a miniaturist style very close to the Matt-Painted pottery productions in the southern Salento region. In order to evaluate the probable contacts between indigenous groups in the Sibaritide and indigenous groups in the Salento area, ten fragments of Salentine pottery has been submitted for analysis with the purpose of compare its compositional characteristic with that of the matt-painted pottery of the local styles and with the local raw materials. The Oinotrian-Euboean group is contemporary with the matt-painted pottery and it is also assumed to have been locally produced. Unlike the traditional indigenous matt-painted ceramics, the Oinotrian-Euboean pottery was produced on a fast rotating potter’s wheel and the shapes and decorations of this vessels are clearly recognisable as Greek. Their production is considered as evidence of the presence of Greek potters who lived and worked within the indigenous settlement near Timpone della Motta from the first half of the 8th century BC. The identification of this material group is of high scientific importance not only for the archaeology of the Sibaritide but for the archaeological understandings of the social, economical and cultural developments in southern Italy during the 8th century BC. However, in order to evaluate the cultural and historical implications, it is very important to clarify if the Oinotrian-Euboean pottery was produced in Francavilla Marittima, therefore ten fragments of Oinotrian-Euboean style pottery were selected for analytical study. Abstract III The fourth pottery class refers to the so-called “Colonial ware”, a term generally used for pottery assumed to have been produced in the Greek colonies. Specifically, our study focused on the many specimens of hydriskai in the sanctuary. The hydriskos, a miniature version of the Greek hydria (water jug), is a wheel made of finely purified clay and generally decorated with horizontal lines and wavy bands, although elaborate floral motifs are also occasionally found. Hydriskoi began to be used in the sanctuary in the late 8th century BC and became the most frequently used vessels during the 7th and 6th centuries BC. Fifteen hydriskos fragments (five of which are over-fired) were examined here. The Sub-Thapsos pottery are imitating Corinthian Geometric pottery of the so called Thapsos class. On the Timpone della Motta this type of pottery has been excavated in archaeological layers dating to the first quarter of the 7th century BC. In southern Italy imitations of Thapsos pottery is found in several locations and it is normally assumed that it was produced locally. It is therefore also of relevance to investigate if a local production imitating Thapsos vessels was taking place in Francavilla Marittima. For this purpose the characteristics of the sub-Thapsos pottery will be compared with that of other ceramic class. All the sherds were examined by means of an integrated analytical approach, including petrographic, mineralogical and chemical investigations. Petrographic thin-section descriptions of samples were made following the scheme proposed by Whitbread (1995), which facilitates detailed characterisation of pottery in terms of microstructure, groundmass and inclusions. Mineralogical characterisation was carried out by X-ray diffraction analysis (XRD). The chemical composition of all samples, in terms of major, minor and trace elements, was determined on pressed powder pellets by X-ray fluorescence spectroscopy (XRF); loss on ignition (L.O.I.) was gravimetrically estimated after overnight heating at 950° C and FeO content by wet titration. Multivariate statistical analysis of chemical XRF data was also carried out. Micro-morphological analyses by scanning electron microscopy (SEM) of the freshly fractured surfaces of all sherds were performed for detailed study of groundmass microstructure and, in particular, of the degree of vitrification. For this aim, the comparative vitrification stages of Maniatis and Tite (1981) were used. Clay sediments from the area around Timpone della Motta, possibly representing raw materials used for local pottery production, were sampled for comparison with the pottery. E. Andaloro IV A first sampling was carried out near the modern town of Francavilla Marittima, in a small outcrop of Miocene clays poorly stratified; in this area were collected 6 samples of clayey materials. Seven samples were taken from the clay intercalation in the outcrops of Pleistocene sands and conglomerates. Were also collected six samples of alluvial clays along the river of Torrente Raganello. Finally, specimens were taken from a large Pliocene clay outcrop, near the modern town of Lauropoli, about three kilometers from the Timpone della Motta site. A total of 15 samples was taken to represent the variation in the entire outcrop; in addition, five samples were collected from an old quarry (not directly belonging to the outcrop but representing a lateral extension of the same layer), located nearby and used for brick production until as little as ten years ago. The mineralogical, chemical and granulometric characterisation of the sampled clay sediments was carried out; the granulometric separation of clay, silt and sand fractions was obtained by sedimentation, according to the method of Dell’Anna and Laviano (1987). To establish pottery firing temperatures, firing tests were carried out on the collected clay samples. One test was prepared for each sample and fired to 950°C, in electric kiln; on each test thin section and diffractometric analysis was carried out. Petrographic observation of impasto pottery found on Timpone della Motta showed a similar composition of the non-plastic fraction in most samples, characterized by sedimentary rock fragments. The presence of grog in three samples shows a small difference in the production technology. Only one sample (LUO10) is very different from the other sherds; the absence of sedimentary rock fragments in the aplastic fraction of this sample suggests, therefore, a different production. The combined information of XRD data and micro-morphological observations by SEM yielded a rough estimate of firing temperatures. Specifically, as the XRD spectra revealed the occurrence of calcite, and SEM analysis didn’t highlighted vitrification microstructures, temperatures lower than 800° C are suggested for all impasto samples. The comparison with the raw materials suggests the use of Miocene sediments for the production of the impasto pottery, but with addition of quartz-rich sand that could came from rivers of Upper Ionian province. Regarding the fine ceramic groups, the optical microscopy demonstrated that the groups of Matt-painted ( “Undulating band” and “Fringe” styles), Oinotrian-euboean, colonial-ware and Sub-Thapsos pottery from Timpone della Motta are characterised by similar petrographic features, all being very fine-textured with only a few small aplastic Abstract V inclusions. In addition, although they are very similar to each other, thin-section observations did highlight some small differences only between the Colonial-ware and Sub-Thapsos group and the other two classes. Specifically, the amorphous concentration features (Acf), mainly consisting of red nodules of isotropic material, which was higher in the hydriskai and Sub-Thapsos samples. The “salentine” matt-painted pottery instead show very different petrographic characteristics, compared to the other ceramic groups. In this class, in addition to the minerals detected in the other fragments, the wairakite mineral was found. According to Maggetti and Heimann (1979) this mineralogical phase could be an alteration product of gehlenite, or of the glassy phase (Deer et al, 1966). The similarity between the chemical compositions of the matt-painted pottery (local styles) and Oinotrian-euboean ceramics could implies their production with the same raw materials; only the sample Oinotrian-euboean 102 shows compositional differences compared to the other fragments. The chemical data for the hydriskai and Sub-Thapsos group showed greater variability, together with some small differences (such as their higher Fe2O3 and MgO contents), with respect to the other two groups. As regards technological features, the combined information of XRD data and micromorphological observations by SEM yielded a rough estimate of firing temperatures. Specifically, as the XRD spectra revealed the occurrence of newly formed Ca-rich phases, and SEM analysis highlighted often extensive vitrification microstructures, temperatures higher than 850° C are inferred for almost all examined samples (Peters and Iberg, 1978; Maniatis and Tite, 1981; Maggetti, 1982; Mazzoleni and Pezzino, 2001; Gliozzo et al., 2005). The few exceptions are represented by the samples 5x and SM16 which show the exclusive presence of abundant calcite and the total lack of any newly-formed phase, thus indicating a temperature lower than 800°C. Concerning the five over-fired hydriskai, the presence of magnetite and cristobalite (Heimann and Maggetti, 1979) along with a continuous degree of vitrification and small and medium-sized bloating pores, allow to estimate a firing temperature higher than 1050°C. The chemical comparisons with the Pliocene and alluvial clay sediments outcropping near Timpone della Motta, which may represent the potential raw materials used for pottery manufacture, allow some general considerations concerning the production area. The E. Andaloro VI studied ceramics, in particular the local styles matt-painted and Oinotrian-Euboean groups, are compositionally similar to both the sampled local clays. The composition of “Salentine” matt-painted pottery is completely different from the collected clayey materials, so very probably, they were not locally produced. The comparison, by optical microscopy, between the fine ceramics and the thin sections of firing tests showed a great similitude with the matrix of the Pliocene clay tests; in addition, only in these firing tests the XRD analysis evidenced diopside and hematite formation, also found in most of the ceramics. The extensive outcrop of Pliocene clay sediments near the archaeological site may explain the large-scale production of pottery ware in this area and, in particular, the great numbers of matt-painted and Oinotrian-Euboean specimens brought to light during excavations. However, in general, the sherds are slightly richer in SiO2 and poorer in CaO than the local clays. These small differences may be explained by the purification process which the raw materials undergone, consisting in the removal not only of larger grains but also of calcareous fossils, quite commonly found. Such a technological process may explain the calcium decrease and the indirect silica increase in the worked clays (Kilikoglou et al., 1988; Fabbri, 1996). The chemical data for the hydriskoi and Sub-Thapsos highlighted greater variability with respect to the other two groups and to the local clays, together with some small differences (such as their higher Fe2O3 and MgO contents). This could mean that this ceramic type was not locally produced or, alternatively, that Feand Mg-enriched clay layers, possibly occurring in Pliocene outcrops nearby the archaeological site, were used to produce this type of pottery, or could be hypothesized that the amorphous nodules were intentionally added. In this case, local production might also be hypothesised for this groups.