II.3. The Pottery Fabrics
p. 29-35
Texte intégral
1In pottery studies one of the major points of departure is the classification of the raw material. The raw material is the fired clay with its intentional or natural additions (inclusions), such as mineral grains and organic remains, etc. depending on the geological conditions of the area (here the Nile valley and the neighbouring desert areas). This fired clay is called “fabric”. A classification system is necessary to divide the ceramic material into groups for better understanding of the distribution of pottery throughout the regions and to pinpoint the places where pottery was made and where it was used. Thus, production and exchange of pottery vessels can be studied. This also enables an understanding of technological processes and the intentional uses of specific raw materials.
The Vienna System
2The Vienna system is a local classification aid devoted to the pottery of the Nile valley. It was formulated by excavators and pottery specialists to enable comparisons of raw materials between sites. The group included Dorothea Arnold, Manfred Bietak, Janine Bourriau, Helen and Jean Jacquet and Hans-Åke Nordström and the system was named after their final meeting of establishment in Vienna in the 1980s (Nordström, Bourriau 1993).
3The major division of the Egyptian raw clays is between the alluvial sediment from the river Nile (and ancient deposits) and raw calcareous marls mined in various desert wadis along the Nile. This distinction is visible in the physical properties of Nile alluvium and Marl clay fabrics even after firing. Nile clay fabrics were fired quite briefly at lower temperatures (600-800 °C), while Marl clay fabrics were fired for longer at 800-1050°C (Nordström, Bourriau 1993). Differences can be seen in the colouring of the pottery (to be measured with a soil colour chart): Nile clay fabrics fire red, reddish brown, light brown and brown, while Marl clay fabrics may be dark red, pink, light red, yellow, green or whitish, both in oxidising conditions; Nile clay fabrics are softer and easier to break than the harder Marl clay fabrics; the sections/sherd breaks differ in terms of porosity and often show zoning: Nile clay fabrics often show a dark core and several oxidation zones in red, purple, reddish yellow and light brown depending on the temperature and duration of the firing process (the oxidation may also be complete in which case the colour is uniform, cf. fig. 8), while Marl clay fabrics are often uniformly coloured and more rarely zoned (cf. Bader 2001). Marl clay vessels appear frequently with a white layer on the surfaces exposed to the kiln gases (exterior in closed vessels (fig. 5b), both interior and exterior in open vessels), which is not a colour slip but probably a chemical reaction of the elements contained in the clay developing this “scum” as the vessel dries and/or fires (Ownby, Griffiths 2009).
4Following this major division, the two Egyptian fabric groups are further sub-divided by the nature of their inclusions and their frequency (fig. 5). For Nile clay fabrics these depend on the presence of organic inclusions (dung, straw) and their fineness (Nile A, B1, B2, C) as well as on limestone particles (Nile D) and a high number of more or less rounded mineral inclusions (Nile E). In Nile C the visible inclusions are various mineral grains of rounded to sub rounded shape in sand size. Also visible are the impressions of organic inclusions, probably straw with some white remains left in the section. They tend to look like desiccated grass (fig. 5a). For the Marl clay fabrics, the division includes porosity and the inclusions (intentional and unintentional) at various frequencies, such as mineral grains, limestone and argillaceous inclusions ( “unmixed marl”, “shale”) and sometimes black grits. Mica is present in most fabrics. Marl C1 is dominated by limestone inclusions that are numerous in this section in variable size. The burnt out limestone inclusions are visible as small holes with white rims. The larger limestone particles are filled with a white or yellowish substance. Most typical of Marl C are the argillaceous inclusions of red-brown colour sometimes with a slate-like texture. These inclusions may be very large and even break through the surface of vessels. Also note the thick white layer on top of the section, which is derived from chemical reactions in the material during drying/firing and not from adding paint (fig. 5b). In addition, the system covers imports from the Levant, the Oases and Sudan. Those are further sub-divided according to their components. The section can best be observed in the field with a 10 × hand lens, when the vessel wall had been freshly broken parallel to the rim, because when turned on a turning device the organic inclusions are arranged parallel to the vessel wall by the rotary kinetic energy and thus are best visible. For fabric description a geological microscope with 30 × magnification is necessary (figs. 7-8).
Figure 5

a) A section of a Nile C2 fabric fragment of a closed vessel from the late Middle Kingdom found at Tell el-Daba..
b) Section of a Marl C1 fabric vessel of closed shape from the late Middle Kingdom found at Tell el-Daba. © B. Bader.
© B. Bader.
Figure 6. Chart of Roundness versus Angularity

From Barraclough 1992.
Figure 7. Density of inclusions

From Terry, Chilingar 1955.
Figure 8. Schematic patterns of sections

After Rye 1981, fig. 104.
5The Vienna system can be considered as a skeleton that may be fleshed out individually as each site and each period may yield different material. Space needs to be devoted to site-specific and chronological variants. This classification system was not intended to “replace” local systems but to provide a vehicle for easy comparison across ancient Egypt and Sudan. This fabric classification system cannot be employed for other geographic areas without amendment as it depends on the material available in the region considered (See Section vi.2).
6The Vienna system is better adapted to certain periods of Egyptian history because the actual pottery used as its basis was derived from the Middle Kingdom to the mid New Kingdom (ca. 2000-1400 BC). As does technology, firing changes over time and this results in Nile B2 of the Middle Kingdom “differing” in several aspects from that of the New Kingdom or the Late Period (cf. Aston 1999), e.g. in density and colouring.
7The study of pottery in the Second Intermediate Period shows that numerous local recipes for pottery-making exist, most apparent in the “Nile B2” fabric at a number of sites, which unfortunately has not included the aid of petrographic analyses so far. While the general classification of Nile B2 is undisputed, in the Nile delta mineral grains dominate, while in the Theban area it is often limestone. At Aswan, the southern limit of Egypt, abundant mica is observed on the surfaces of the pottery. Thus, the raw material of the alluvial pottery in this period attests to several production places throughout the regions that were not centralised.
Petrographic Characterisation of Ceramic Fabrics
8As noted, the Vienna System is a broad classificatory method for inter-site comparison, but most excavations create their own fabric groupings based on the studied ceramic corpus. In order to clarify these groupings and relate the material to the Vienna System, petrographic analysis is performed. This technique employs a geological microscope to examine a thin slice of pottery placed on a glass slide. The characteristics of the minerals and rock fragments under crossed polarising and plane polarising light identifies them. Features of the clay, though the particles themselves are too small to see, can be described. Collectively, the petrographically defined inclusions and clay appearance are classified as a petrofabric with individual samples being assigned to particular petrofabric groups. This method is ideal for relating fabric to raw material source and comparing amongst samples (see Ownby, Brand 2019 for an overview of petrographic work in Egypt; see Ownby 2016 for petrographic analysis of Vienna System fabrics). It is worth noting that chemical analyses via neutron activation analysis have been performed on a fair number of sherds representing the Vienna System Fabric groups (Al-Dayel 1995 and Bourriau et al. 2006).
9Petrographic analysis of the Nile A fabric of the Vienna System typically confirms that it is composed of fine Nile clay without the addition of sand, plant remains, or grog (i.e. crushed pottery). Such clay can be acquired from naturally levigated sources in canals or from intentionally created settling pools that allow coarse material to fall to the bottom leaving finer clay at the top. Nile B1, as seen in thin section, comprises Nile clay with some medium to coarse mineral inclusions, usually quartz and feldspars. These often appear natural to the clay and suggest the selection of coarser Nile clay along the river or canals. Rare fine plant remains may occur. Nile B2 is similar though can have increased medium to coarse mineral inclusions and plant remains. For some fabrics the addition of sand and plant remains as temper can be suggested, but other analysed fabrics that would be classified as Nile B2 appear also to have natural coarse inclusions. Rare limestone may be present in both Nile B1 and Nile B2, and the fabrics are probably a continuum of naturally or artificially made clay paste recipes. Nile C is notable macroscopically and microscopically for the addition of common, coarse plant remains and was often used for bread moulds and beer jars (fig. 5a). The Nile clay itself is similar in texture to that employed for Nile B1 and Nile B2. Likewise, Nile D is composed of Nile clay with a similar texture to the other fabrics, but clearly added numerous coarse limestone pieces. In some cases, this fabric can be confused with Nile and Marl clay mixed fabrics (infra). Finally, Nile E is distinguished based on the common sand that was probably added and appears as medium to coarse-sized rounded quartz, feldspar and quartzite grains (cf. fig. 6). However, many fabrics fall somewhere in between a Nile E and a Nile B, Nile C or Nile D.
10The Marl clay fabrics are difficult to define macroscopically and petrographically. Marl A1 fabrics have a fine, dense clay with few inclusions but common limestone. This could be an intentional addition or natural to the clay. Marl A2 is probably natural clay with some inherent mineral grains and limestone, but notable pieces of unmixed clay. In this case, the clay itself was more likely from a shale deposit rather than carbonate formations that produce true Marl clay. Shale clays often occur below carbonate layers, and the weathering of both can produce a secondary clay deposit of mixed shale and calcareous material. Marl A3 is also a dense fabric with some natural inclusions. It is distinct due to its light greenish colour. Marl A4 is notable due to the likely addition of sand producing a sandy and coarse fabric. In some cases, this sand may derive from the presence of Nile clay, either added intentionally or from a clay deposit where Nile flood plain material has mixed with calcareous clay at the outlet of a wadi. These are termed “mixed clays” fabrics and are often subsumed under the Marl clay fabric groups. They are identified by more common mica, volcanic rock fragments, and clay pellets. The Marl B fabric is also sandy, possibly representing added temper, and has visible limestone like Marl A4. Marl C is probably the most petrographically studied of all the Marl fabrics and such analyses suggest the source is shale clay rather than true calcareous Marl clay. Shale fragments are readily seen in the fabric with Marl C1 having added limestone, while Marl C2 is dominated by sand temper. Marl D also features common limestone that could be temper unlike the natural limestone present in most Marl A and Marl B fabrics. Marl E has rarely been studied but is notable for the plant remains in the fabric. Finally, Marl F has been defined for late Second Intermediate/ early New Kingdom ceramics in the Delta but is a variable fabric ranging from more or less calcareous with some having added sand and/or limestone.
Fabric description form

Persistent identifer: https://doi.org/10.34847/nkl.bba7d31k.
Download (pdf/333 kb): https://api.nakala.fr/data/10.34847/nkl.bba7d31k/3ae0ea1b95bfd598cff4afaa41e81d1ebd3957ca
11Recent petrographic studies have now clarified the kaolinitic clays used in the Aswan area and their variability. As with Marl clay, the Aswan clay fabrics can have a Nile clay component, but it is similarly difficult to specify if such mixes occur naturally or were created by the potter. Several oases fabrics are now more clearly defined, especially those from Kharga, Dakhla and Bahariya. Such work has enabled the identification of these vessels in the Nile Valley and ascribed them to a specific oasis. This information clarifies the movement of pottery from the Nile Valley to the oases, and petrographic research as a whole has highlighted the movement of pottery along the Nile over long periods of time. It has become clear that though much pottery production takes place locally with local fabrics, some productions are meant to be traded far and wide.
Auteurs
Head of Research Group Archaeology in Egypt and Sudan. Department for Prehistory and Western Asian and Northeast African Archaeology. Austrian Archaeological Institute. Austrian Academy of Sciences, Wien, Austria.
Research Petrographer, Desert Archaeology, Inc., University of Arizona, Tucson, USA.

Le texte seul est utilisable sous licence Creative Commons - Attribution - Partage dans les Mêmes Conditions 4.0 International - CC BY-SA 4.0. Les autres éléments (illustrations, fichiers annexes importés) sont « Tous droits réservés », sauf mention contraire.
Rural-Urban Dynamics in the East African Mountains
Sylvain Racaud, Bob R. Nakileza, François Bart et al. (dir.)
2016
Kenya’s Past as Prologue
Voters, Violence and the 2013 General Election
Christian Thibon, Marie-Aude Fouéré, Mildred Ndeda et al. (dir.)
2014
Music and Dance in Eastern Africa
Current Research in Humanities and Social Sciences
Kahithe Kiiru et Maina wa Mũtonya (dir.)
2018
Where Women Are
Gender & The 2017 Kenyan Elections
Nanjala Nyabola et Marie-Emmanuelle Pommerolle (dir.)
2018
Le Kenya en marche, 2000-2020
Marie-Aude Fouéré, Marie-Emmanuelle Pommerolle et Christian Thibon (dir.)
2020
Kenya in Motion 2000-2020
Marie-Aude Fouéré, Marie-Emmanuelle Pommerolle et Christian Thibon (dir.)
2021