The Materiality of Dung> the Manipulation of Dung in Neolithic
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UDK 903.28ı14(292.46)"633\634">636 Documenta Praehistorica XXXVI (2009) The materiality of dung> the manipulation of dung in Neolithic Mediterranean caves Dimitrij Mleku/ Ghent University, Faculty of Arts and Philosophy, Department of Archaeology and ancient history of Europe, BE [email protected] ABSTRACT – This paper discusses the formation of layers of burnt herbivore dung in Neolithic, Eneo- lithic and Bronze Age Mediterranean caves. While these layers are clearly connected with transhu- mant pastoralism and the practice of keeping herds in the caves, their formation should not be seen as the result of purely practical and ‘rational’ reasons. In this paper, I develop an argument that they are remnants of a complex manipulation of substances which includes burning dung to make white ash. Thus instead of seeing dung as a culturally neutral refuse which has to be disposed of, we might see its burning and deposition as the cultural manipulation of potent substance. IZVLE∞EK – ∞lanek se ukvarja z nastankom plasti se∫ganega ∫ivalskega gnoja v neolitiku, eneolitiku in bronasti dobi v jamah Sredozemlja. Te plasti so nedvomno povezane s transhumantnim pa∏ni∏t- vom in prakso zapiranja ∫ivali v jame, a njihovega nastanka ne moremo pripisati zgolj prakti≠nim in ‘racionalnim’ razlogom. ∞lanek razvija argument, da so te plasti rezulat kompleksnega manipu- liranja s snovmi, ki vklju≠uje tudi se∫ig gnoja in njegovo transformacijo v bel pepel. Gnoj ni bil kul- turno nevtralen odpad, ki se ga je potrebno znebiti; premikanje, se∫ig in odlaganje pepela je potreb- no razumeti kot kulturno manipulacijo potencialno mo≠ne substance. KEY WORDS – archaeology; Neolithic; Mediterranean; herding; dung; materiality Introduction Neolithic, Copper and Bronze age occupation levels microscopic crystals of calcium salt and grass phyto- in Mediterranean caves often consist of curious white lits. This leads to the identification of herding strate- powdery sediments. They were recently identified as gies and penning practices in Mediterranean caves layers of burnt herbivore dung. They represent the from the Neolithic onwards. Thus, in the Neolithic, remnants of complex manipulations of matter, which Eneolithic and the Bronze Age, caves were used as includes the burning of dung to create white ash. pens for domestic animals, mostly sheep and goat. These sediments pose a number of interesting que- This is further supported by the identification of shed stion, not only on how and why they were produ- milk teeth often found in stable deposits. However, ced, but also what meanings are objectified in the there is also evidence that caves were probably used materiality of dung and the daily practices associa- simultaneously for domestic activities. Caves were ted with it. obviously seasonal stations in the system of transhu- mance (Boschian and Montagnari Kokelj 2000; Overview: burnt animal dung Mleku∫ 2005; Miracle and Forenbaher 2005). The pioneering work of Jacques É. Brochier (1991; A unique depositional practice identified in many of 1992; 1996; 2002; 2006) has demonstrated that mi- these caves consisted of the burning of animal dung. neralized dung residues in archaeological deposits This practice can be recognized in layers of either can be identified by the occurrence of spherulites, alternating black and white lenses (so called ‘layer- DOI: 10.4312/dp.36.14 219 Dimitrij Mleku/ cake’ deposits), or white powdery lenses embedded available. Cattle dung is formed into ‘cakes’ which in the sediment. The thin, layered lenses suggest that are dried in the sun and stored as fuel for cooking the process was repeated cyclically, probably over a and heating fires. long period. ‘Buffalo chips’ or ‘bois de vache’, bison dung, were Herbivore dung collected and used as fuel in the plains of north America (Brink 2008). Various travelers reported Herbivores can produce large quantities of dung. that dung “in dry weather is a an excellent sub- Modern sheep breeds can produce around 1.5kg per stitute for wood, but when moistened by rain, the day, which amounts to between 500 and 900 kg/year smoldering pile will smoke for hours before it con- per animal; goats are even more productive. Cattle descends to burn” (cited in Brink 2008.198) and can produce up to 10 000kg of dung per year per ani- that smoke from buffalo chips “produces an ardent, mal (Slicher van Bath 1963). And even if animals but transient flame, sufficient for cooking our daily do not stay in caves for the whole year and only food; but evolves a smoke, which, to the nasal or- part of the day (night, midday), a small herd can gans of a stranger, is far from agreeable” (Brink produce a large quantity of dung. Thus a herd of 100 2008.198). sheep, which spends 8 hours per day in a cave for a month, can accumulate around 4000kg of fresh dung. Experiments suggest that cow dung fueled fire can reach a maximum temperature of 640 degrees Cel- Cow dung has a high water content – around two to sius and sheep dung maximum of 570 degrees C. three times its dry weight (fresh dung is 75–60% Sheep pellets can smolder for quite some time (Sha- water), but this greatly depends on diet and season hack Gross 2008). (Dickinson et al. 1981.129–41). Sheep and goat dung has a lower water content. The burning of dung depends on many variables, first and most important being water content. Dung Experiments on cow pats have shown that water con- that is improperly dried can produce a lot of smoke tent falls rapidly (to below 100% of dry weight) over and can be very difficult to ignite. The second factor the first few weeks following excretion if it is protec- is oxygen supply. Some reports suggest that dung ted from rainfall. Dung contains around 50% of orga- fueled fire needs steady a supply of air in order to nic content, which is highly dependent on diet regi- burn properly; without sufficient wind, it smolders, mes. Protected dung pats show little loss of water produces a lot of smoke and gives off little heat. The content in the first months after excretion. Even less third variable is composition, which depends on ani- noticeable is the loss of calorific values (Dickinson mal species and diet. et al. 1981). In some cases, piles of fresh dung can ignite and In dry, warm conditions a thick crust is formed over burn spontaneously, due to the heat released during the pat, which protects it from leaching. In caves the decomposition and oxidation of cellulose mate- where sheep are penned, the formation of ‘migon’, a rial. In large dung piles with a limited oxygen sup- dried surface comprised of a trampled accumulation ply, a smoldering fire starts when organic material of soft sheep dung can be observed. It consists of a reaches ignition temperature. This type of fire pro- dark, compacted organic paste, which breaks into duces smoke and heat, but no flame. When more platelike shapes; deep desiccation cracks form dur- oxygen is present, a glowing fire can occur, produ- ing the dry season (Dickinson et al. 1981). cing smoke, more heat and higher temperatures. With abundant oxygen, a flaming fire with very high However, in the long term (decades, centuries), a temperatures will ensue (James 1928.481–5). process of mineralization, the loss of degradable organic matter through oxidation, slowly transforms Deposition practices dung into a layer of phytolits, calcareous spherulites and detritic dust. Lets return to the black and white sediments in the Mediterranean caves. We now know that the major Dung as fuel quantity of deposits derives from herbivore dung al- tered in many ways, either by burning, by the slow Dung can burn and, is used as fuel in many parts of process of mineralization and different kinds of re- the world, especially where firewood is not readily working. But how exactly did these formation pro- 220 The materiality of dung> the manipulation of dung in Neolithic Mediterranean caves cesses operate; how were dung deposits manipu- lated? One of the most distinctive features are ‘layer cake’ sediments of alternating white and black lenses. The layers are thin and form stacks that can be up to se- veral meters thick. Theses sediments cover large areas of the caves (Fig. 1). Layer cake sediments are the result of the periodi- cal burning of the dried and trampled dung deposi- ted on the cave floor (migon). Thus in layer cake se- diments, with alternating black/white layers each combination of white and black layer is a remnant of a single burning event and probably relates to a single occupation of the cave. White ashy layers are the result of properly burned dung, while thinner black layers comprise the bottom and lateral parts of the burnt dung, and contain charred and partially burned organic matter (Brochier 2002). The formation of such sediments was observed in Greek and Sicily caves (Acovitsioti-Hameau et al. 1988; Brochier et al. 1992). At the end of autumn, after a summer period of drying, shepherds burn the dung deposited in sheep pens. All except the wet- test areas are burnt. Contact between the burnt and Fig. 1. ‘Layer cake’ deposits from Eneolithic and unburnt material results in a black carbonaceous la- Bronze Age layers of Grotta Cotariova/∞otarjeva jama, Italy (after Montagnari Kokelj et al. 2002. yer at the bottom and edges of the burnt ashy la- Fig. 8). yer. The ashy layer is discontinuous and, like exam- ples from archaeological excavations, has an irregu- deposits, with abundant cultural remains. At micro- lar outline (Fig. 2). scopic scale, they appear to be a mix of several com- ponents, such as large charcoal fragments, organic There are many practical reasons for burning dung.