Ceramic Petrology and the Study of Anglo-Saxon and Later Medieval Ceramics

Abstract

A SURVEY of archaeological ceramic thin sections held by institutions and individuals in the United Kingdom was undertaken in the early 1990s by the City of Lincoln Archaeology Unit and funded by English Heritage. Over 6,000 thin sections of Anglo-Saxon or medieval date (or reports on their analysis) were located. For the Middle to Late Anglo-Saxon and the post-Conquest Periods, these studies have confirmed that pottery production was carried out in a limited number of centres and that most pottery, including handmade coarsewares, was therefore produced for trade. The distances over which pottery was carried vary from period to period but were actually as high or higher in the Middle to Late Anglo-Saxon Period as in the 13th to 14h centuries. However, for the Early Anglo-Saxon Period (and the Middle Anglo-Saxon Period outside of eastern England) the evidence of ceramic petrology is equivocal and requires more study. These 6,000–odd thin sections represent a resource which could be used for various future studies, some of which are discussed here, and as an aid to their further use a database containing information on the sampled ceramics, their location and publications of their analyses will be published online through Internet Archaeology.     

CHEMICAL AND MINERALOGICAL CHARACTERIZATION OF SASANIAN AND EARLY ISLAMIC GLAZED CERAMICS FROM THE DEH LURAN PLAIN,SOUTHWESTERN IRAN*

One hundred and seventy‐five glazed ceramics from Sasanian and Early Islamic period sites located on the Deh Luran Plain in southwestern Iran were examined by instrumental neutron activation analysis for characterizing differences in ceramic pastes and by laser‐ablation inductively coupled plasma mass‐spectrometry for identifying the constituents of the ceramic glazes. The results of the analysis reveal that alkaline‐based glazed ceramics have paste compositions that are distinct from contemporary and later ceramics decorated with alkaline–low‐lead and lead‐based glazes.     

The Archaeology of Al-Andalus: Past,Present and Future

Abstract

THIS PAPER PRESENTS AN OVERVIEW of the archaeology of al-Andalus (the Arabic name for Islamic Spain and Portugal), from its beginnings in the late 1970s to the present day. Innovative approaches and challenging theoretical stances made the archaeology of al-Andalus the spearhead of medieval archaeology in Iberia between the 1980s and 1990s. A problematic, and often conflicting, relationship between archaeology and history has characterised medieval archaeology in Spain since its inception, however, and a new awareness of these problems is emerging. This paper reviews past and current attitudes to such challenges and reflects on the future needs of the discipline. It also reflects on the politics of archaeology and on the role of medieval archaeology in revealing social change, which has until now been underrated.     

GLAZED CERAMIC MANUFACTURING IN SOUTHERN TUSCANY (ITALY): EVIDENCE OF TECHNOLOGICAL CONTINUITY THROUGHOUT THE MEDIEVAL PERIOD (10TH–14TH CENTURIES)*

Archaeometric investigation allowed the characterization of two important classes of ceramics: ‘vetrina sparsa’ and ‘invetriata grezza’. Their archaeological peculiarity makes them particularly suited for tracing the evolution of glaze manufacturing in southern Tuscany throughout the medieval period (10th–14th centuries). These ceramics were found in different sites of historical importance, and also from a mining perspective. Local copper, lead, zinc and iron mineralizations supported the growth of several settlements in the vicinity of the mines. The many castles and different archaeological finds (ceramics, glazed ceramic, slag etc.) attest to the intense mineral exploitation of the area from at least the first millennium bc up to the modern period. In light of these geological and archaeological characteristics, archaeometric investigation was intended to provide insight into ancient technical knowledge of ceramic glazing and to determine the source area for raw materials in the medieval period (10th–14th centuries). Ceramic bodies were analysed through OM, XRDp, SEM–EDS and XRF, while coatings were investigated through SEM–EDS. Mineralogical, petrographic and chemical analyses revealed slightly different preparation and firing processes for the two classes of ceramics. These data suggest the continuity through the centuries of the ‘vetrina sparsa’ and ‘invetriata grezza’ production technology. The mineralogical phases, such as monazite, xenotime, zircon, barite, Ti oxide, ilmenite, titanite, tourmaline and ilvaite, and the lithic (intrusive and volcanic) fragments detected within the ceramic bodies suggest a source area in the vicinity of the Campiglia mining district. Lastly, the presence of Cu–Zn–Pb (Ag) and Fe sulphide mineralizations (materials used to produce glaze) in the area supports the hypothesis of local manufacture.     

THE BEGINNINGS OF ISLAMIC STONEPASTE TECHNOLOGY*

A multidisciplinary programme of research on Islamic pottery has been focused on questions of the dating, provenance and technology of Islamic pottery. One particular question has been the development of stonepaste, a material made primarily of crushed quartz with added frit-glass and clay. The combination of the different approaches of this study has revealed early foundations for the technology in ninth-century AD Iraq, apparently originating in the clay ceramic rather than the ‘Egyptian faience’ tradition. Subsequent and final practice developed in tenth- and eleventh-century AD Egypt. This technology becomes the primary body for all fine Islamic ceramics.     

NEUTRON ACTIVATION ANALYSIS AT THE BRITISH MUSEUM,LONDON

Neutron activation analysis was used at the British Museum from 1978 until 2002 for provenance studies on ceramics and marble. Significant numbers of the items analysed were of high quality and value, and careful sampling was necessary to avoid damage to the object. An in‐house British Museum Standard Pottery was established and inter‐calibrated with a number of standards used by other archaeometry laboratories. The results of the projects have been published in many papers, and the databases established will be of use to future scholars interested in the ceramic groups represented. Projects on Greek and Near Eastern pottery have been undertaken. Relatively large numbers of north European medieval and post‐medieval pottery samples were analysed, as well as the tin‐glazed ceramics of Spain and Italy. Classical marble has also formed the subject of another project and a database of quarry material has been established.     

Stable Isotope Record of Human and Sheep Enamel Carbonate from the Ancient Middle Euphrates Valley (Syria)

Stable isotope analyses of human tooth enamel have allowed us to reconstruct the isotope composition of dietary carbon, changes in the oxygen isotope composition of drinking water and the possible migration of humans in ancient Terqa and Tell Masaikh (SE Syria). δ¹⁸O_carbonate values of human tooth enamel from the interval comprising the Neo‐Assyrian to the modern Islamic periods (from 900 BC to AD 1949) generally mirror the isotope composition of Euphrates water, which is believed to have been a major drinking water source. Lower δ¹⁸O_carbonate values of human Bronze Age apatite are linked to a different hydrologic system that was present in the Middle Euphrates valley at that time (2650–1700 BC). Higher δ¹⁸O_carbonate values of some individuals in the Neo‐Assyrian (900–700 BC) and Islamic periods (AD 600–1200) may indicate human migration from the interior of the Near East. Low δ¹³C_carbonate values (−11.3 to −12.4‰) of human tooth enamel from the interval comprising the Early Bronze to the Islamic periods (from 2650 BC to AD 1200) indicate C₃ plants as a predominant source of dietary carbon. Changes in human dietary customs in SE Syria (with inferred usage of C₄ plants) occurred in the modern Islamic period only (AD 1850–1949). Oxygen and carbon isotope data of sheep enamel show the usage of water bodies characterised by an enhanced evaporation rate during the Neo‐Assyrian time (900–700 BC) and grazing sheep herds on drier areas during the Islamic and the modern Islamic periods (after AD 600). Copyright © 2015 John Wiley & Sons, Ltd.     

THE PROVENANCE AND TECHNOLOGY OF NEAR EASTERN GLASS: OXYGEN ISOTOPES BY LASER FLUORINATION AS A COMPLEMENT TO STRONTIUM*

The ability to make rapid measurements on small samples using laser fluorination enhances the potential of oxygen isotopes in the investigation of early inorganic materials and technologies. δ¹⁸O and ⁸⁷Sr/⁸⁶Sr values are presented for glass from two primary production sites, four secondary production sites and a consumer site in the Near East, dating from Late Antiquity to the medieval period. δ¹⁸O is in general slightly less effective than ⁸⁷Sr/⁸⁶Sr in discriminating between sources, as the spread of measured values from a single source is somewhat broader relative to the available range. However, while ⁸⁷Sr/⁸⁶Sr is derived predominantly from either the lime‐bearing fraction of the glass‐making sand or the plant ash used as a source of alkali, δ¹⁸O derives mainly from the silica. Thus the two measurements can provide complementary information. A comparison of δ¹⁸O for late Roman – Islamic glasses made on the coast of Syria–Palestine with those of previously analysed glasses from Roman Europe suggests that the European glasses are relatively enriched in ¹⁸O. This appears to contradict the view that most Roman glass was made using Levantine sand and possible interpretations are discussed.     

Common ware production at Thamusida: dating and characterisation of Roman and Islamic pottery

Twenty-one samples of likely Roman, likely Islamic and unknown common ware from the archaeological site of Thamusida (Rabat, Morocco) were analysed in order to anchor selected types of pottery to a limited time span and, possibly, to a production area and technology. Analytical techniques were thermoluminescence, optical microscopy, scanning electron microscopy and X-ray fluorescence. The results arising from this research are definitely useful for the study of the site of Thamusida as well as for all researchers involved in archaeological and archaeometrical research in Morocco. Chronologies proposed on a typological base have been denied twice: a likely Islamic cup dates back to the second century a.d.; vice versa, a stewpot, framed into the Roman period, resulted to be an eighth century a.d. production. Moreover, the identification of an eighteenth century ceramic production is of outstanding importance, as it characterises a completely unknown production. Regarding the production area, four samples of both Roman and Islamic periods have been recognised as local productions of Thamusida.     

Radical changes in Islamic glass technology: evidence for conservatism and experimentation with new glass recipes from early and middle Islamic Raqqa,Syria*

The chemical analysis of excavated glass fragments from dated archaeological contexts in Raqqa, Syria, has provided a detailed picture of the chemical compositions of artefacts deriving from eighth to ninth and 11th century glassmaking and glassworking activities. Evidence for primary glass production has been found at three excavated sites, of eighth to ninth, 11th and 12th century dates; the first two are discussed here. The 2 km long industrial complex at al‐Raqqa was associated with an urban landscape consisting of two Islamic cities (al‐Raqqa and al‐Rafika) and a series of palace complexes. The glass fused and worked there was presumably for local as well as for regional consumption. Al‐Raqqa currently appears to have produced the earliest well‐dated production on record in the Middle East of an Islamic high‐magnesia glass based on an alkaline plant ash flux and quartz. An eighth to ninth century late ‘Roman’/Byzantine soda–lime recipe of natron and sand begins to be replaced in the eighth to ninth century by a plant ash – quartz Islamic soda–lime composition. By the 11th century, this process was nearly complete. The early Islamic natron glass compositional group from al‐Raqqa shows very little spread in values, indicating a repeatedly well‐controlled process with the use of chemically homogeneous raw materials. A compositionally more diffuse range of eighth to ninth century plant ash glass compositions have been identified. One is not only distinct from established groups of plant ash and natron glasses, but is believed to be the result of experimentation with new raw material combinations. Compositional analysis of primary production waste including furnace glass (raw glass adhering to furnace brick) shows that contemporary glasses of three distinct plant ash types based on various combinations of plant ash, quartz and sand were being made in al‐Raqqa during the late eighth to ninth centuries. This is a uniquely wide compositional range from an ancient glass production site, offering new insights into the complexity of Islamic glass technology at a time of change and innovation.     

Corona Remotely-Sensed Imagery in Dryland Archaeology: The Islamic City of al-Raqqa,Syria

Abstract

Satellite remote sensing has seen some use in archaeological research, although its effectiveness has been restricted by the low spatial resolution and the high cost of available imagery. In 1995 the United States declassified 860,000 high-resolution Corona satellite photographs, acquired for intelligence purposes between 1960 and 1972. Corona offers global coverage with an emphasis on areas of strategic significance to the United States. The imagery has been released into the public domain at low cost of acquisition. In this paper we explore the potential of Corona imagery in archaeological investigations using as an example the topography and cultural landscape of the early Islamic city of al-Raqqa in northern Syria.     

Notes and News

Abstract

This paper seeks to cast some light on a so-called Green Man ivory knife handle from Perth and on the cultural context from which it sprang. It was made and lost or disposed of during the 14th century and, although its full life-story includes its archaeological recovery and subsequent curation in Perth Museum, its main importance lies in what it can tell us of medieval people. Exploring its material and production, its function as a handle, its iconography and its cultural background reveals this importance. Bringing these strands together gives us a snapshot of medieval cognition, focusing, on the way elements of seasonal ritual were consumed in the medieval burgh of Perth.     

Temporal Patterns in Ceramic Production in the Berbati Valley,Greece

Abstract

This research explores temporal patterns in the procurement of raw materials for ceramic production, based mainly on material recovered in regional survey. The underlying premise is that potters in different cultural phases will preferentially exploit the same geological landscape for the most suitable raw materials, but different materials may be preferred depending upon the potter's technological traditions. A program of petrographic and chemical analyses was carried out on ceramics from the Berbati-Limnes Archaeological Survey, Argolid, Greece. Ceramic fabrics from several cultural phases were studied and compared with patterns of settlement within the valley. The results show that ceramics from regional surveys can be used to identify broad patterns of change in exploitation of the same landscape. In some cases these patterns correlate with changes in settlement and may indicate that different choices in raw material procurement mark the arrival of potters from outside the valley.     

Digital Support for Archaeology

Abstract

We describe an interdisciplinary approach in which computer scientists develop techniques to support archaeology. In the Reading Images for the Cultural Heritage (RICH) project, a variety of methods have been developed to support archaeologists in the visualization, categorization, and characterization of archaeological objects, such as medieval glass, coins, ceramics, and seeds. The methods are based on image processing and machine learning algorithms that are tailored to the task at hand. We describe the algorithms and illustrate their application on archaeological datasets. The virtues and pitfalls of the interdisciplinary approach to archaeology are discussed.     

Crema Ware and Elite Power at Monte Albán: Ceramic Production and Iconography in the Oaxaca Valley,Mexico

Abstract

During the Terminal Formative, or Monte Albán II period (ca. 100 B.C.-A.D. 200), the Zapotec state was centered in the Oaxaca Valley, Mexico. Reassessment of ceramic data from excavations at the Zapotec capital of Monte Albán, in conjunction with data acquired from recent investigations at a secondary center (Cerro Tilcajete) and a tertiary center (Yaasuchi) in the Oaxaca Valley, sheds light on the production and distribution of elaborately decorated crema- (cream-) paste ceramics. This analysis suggests that such ceramics were produced at Monte Albán as prestige goods and distributed to local elites residing at administrative sites throughout the valley. The distribution of decorated crema vessels—and in particular, bowls bearing incised lightning motifs associated with the preeminent Zapotec deity, Cociyo—via gift-giving networks represented an attempt by elites at the capital to control local elites and integrate them into the regional sociopolitical hierarchy. Data from Cerro Tilcajete and Yaasuchi indicate that local elites at these centers acquired and used some crema vessels. These vessels were fewer in number and less varied than the cremas enjoyed by elites at the capital. Elites at Cerro Tilcajete and Yaasuchi apparently sponsored the local production of ceramics intended to imitate crema vessels. By supplementing the flow of true crema ceramics from Monte Albán, the production of local imitations would have subverted attempts by elites at the capital to control both the distribution of prestigious ceramics and the subordinate elites who desired them. This regional study of ceramics in the Oaxaca Valley illustrates the intersection of economy and ideology in state society, as well as the role that prestige goods can play in the creation and legitimization of—as well as resistance to—institutionalized sociopolitical difftrences.     

The technological development of stonepaste ceramics from the Islamic Middle East

The microstructures and chemical compositions of stonepaste bodies from the Islamic Middle East, typically produced from a mixture of ten parts crushed quartz, one part crushed glass and one part white clay, are investigated using analytical scanning electron microscopy. For comparison, replicate stonepaste bodies are produced in the laboratory at firing temperatures in the range 900–1200 °C, and are similarly examined. The stonepaste bodies are divided into four primary microstructural groups that reflect the increasing reaction during firing of the glass fragments with the clay and quartz particles. The observed microstructures are then used to assess the geographical and chronological variations in the production technology of stonepaste ceramics from Egypt, Syria, Iran, Uzbekistan and Turkey, spanning the period from 11th to 17th centuries AD.     

Archaeometric study of medieval pottery excavated at Stari (Old) Ras,Serbia

A combined study of a series of polychromatic and monochromatic glazed medieval pottery shards excavated from the archaeological area of Stari (Old) Ras in southern Serbia, including petrographic and chemical analysis, powder X-ray diffraction (PXRD) and Fourier transform infrared (FTIR) spectroscopy, allowed us to clearly distinguish between two groups of ceramics. Ras pottery, made of fine-grained well-cleaned clay and characterised by a rich mineral assemblage, was produced by firing in a temperature range between 800 and 900 °C. Reljina Gradina ceramics were produced at similar temperatures from materials which, with regard to mineralogical and chemical composition, show clear similarity with local clay, suggesting that these samples are of local origin and production. This work is the first systematic archaeometric study of medieval pottery excavated on the territory of Serbia.     

From pedologic indications to archaeological reconstruction: deciphering land use in the Islamic period in the Baida district (north-western Sicily)

The aim of this work was to detect imprints on soil properties from former Islamic land use (9th to 11th century) using a multi-method, soil-chemical approach. Four soil profiles (with buried horizons) found in the vicinities of former Islamic settlements in Sicily were analysed for phosphorus (total, organic and inorganic), nitrogen (total, NO₃⁻ and NH₄⁺), carbon compounds (δ¹³C, lipids, polycyclic aromatic hydrocarbons (PAH) and functional groups), physical and chemical C-fractions and the state of soil weathering. Two soil profiles contained ceramic sherds from the Islamic period. Inorganic nitrogen forms, phosphorous and the PAH content indicated strong impacts from traditional agriculture and/or burning. Radiocarbon dating of soil organic carbon (SOC) fractions from buried horizons showed that distinct changes must have occurred during the Islamic epoch. The isotopic composition of SOC indicated that land use was probably different in earlier times. C₄ plant cultivation was expected but surprisingly lipid analyses did not confirm this. A high amount of aliphates and low C/N ratio indicated a good, long-term SOC stabilisation under the native conditions combined with Islamic land use. The irrigation of the soils probably increased the production of weakly-crystalline Fe forms that helped to stabilise SOC.     

THE TECHNOLOGY OF GLAZED ISLAMIC CERAMICS USING DATA COLLECTED BY THE LATE ALEXANDER KACZMARCZYK

During the 1980s, the late Alexander Kaczmarczyk undertook the analysis of some 1200 glazed Islamic ceramics from Egypt, Iran, Iraq and Syria spanning the period from the eighth to the 14th centuries ad , using a combination of XRF for the glazes, and AAS or PIXE for the bodies. The aim of the present paper is, first, to bring to the attention of researchers into Islamic ceramics the fact that these analytical data are available on the Research Laboratory for Archaeology and the History of Art website, and also that some 400 of the analysed sherds are held in the Research Laboratory. Second, the paper provides a preliminary interpretation of the analytical data in terms of the choice of glaze type (i.e., alkali–lime, lead–alkali and high‐lead), tin‐opacification, body type (i.e., quartz or stonepaste, calcareous clay, and non‐calcareous clay), and colorants.