The Use of Animal Bone as Fuel in the Third Millennium BC Walled Enclosure of Castanheiro do Vento (Northern Portugal)

Abstract

Experiments on fire manipulation of bones as fuel demonstrated that animal bones are effective in the act of maintaining lasting combustion. These experiments are almost always applied to the studies in hunter-gather societies in prehistory, even though the use of bones as fuel is also known in historical times. Based on data and models resulting from these recent experiments, both in laboratory and in real hearths, I tested the hypothesis of the use of animal bone as fuel in the third/second millennium BC walled enclosure of Castanheiro do Vento, in northern Portugal. The faunal assemblage shows some specific characteristics such as a very low percentage of identifiable material and close to 90% of charred bones with a very high index of fragmentation I link the faunal analysis with the results of some experiments recently published. These experiments show the particularities of bone fuel combustion, specifically used in certain activities. Nevertheless, the interpretation of these activities in Castanheiro do Vento is difficult to achieve because of the preliminary state of the investigations. As an additional problem, the available interpretations in the literature concern mostly hunter-gather, and models do not take into account the complex societies of the third/second millennium BC.

Faunal Remains from Torre Velha 12 (Serpa, Beja, Southwest of Portugal): Relationship between Animals and Bronze Age Communities

“…Breakage was differentiated as recent break, green break and dry break. For burnt fragments, we have considered the alterations of the natural color of bones surfaces to understand the degrees of burning: light brown, dark brown or grey/blue [23,24].…”

Stone lines and burnt bones: ritual elaborations in Xiongnu mortuary arenas of Inner Asia

“…The high frequency of calcined bones (around 30 per cent), high fragmentation rates (around 85 per cent of bone fragments smaller than 10mm in size for most deposits), and prevalence of shaft/rib fragments (approximately 95 per cent) exhibiting transverse and right-angle fracture patterns, are all consistent with fragmentation caused by thermal alteration (Théry-Perisot et al . 2005; Costa 2015). Along with a high abundance of spongy bone (e.g.…”

“…Although intensive processing of carcasses for marrow extraction may have occurred as part of Xiongnu food-focused ceremonies, the presence of fresh breakage fractures could also reflect the intentional dismantling of bones to increase the energy availability provided by fat. Although this processing would decrease fire duration somewhat, it would effectively increase fire intensity (Costa 2015). Notably, bone-fuelled fires, while providing long-lasting flames, are generally low energy and not suitable for cooking (Théry-Perisot et al .…”

“…Of the three stone pairs north of THL-64 that contained deposits, the taxonomic and skeletal element composition—as well as the quantity of faunal remains—varied somewhat (Figure 6). The duration of burning is influenced by the amount of bone placed in the fire (Costa 2015); the stone-line deposits containing few bone fragments may have fuelled shorter-lived fires. At THL-64, stone pair 3.4 yielded remains comprising a few medium mammal rib fragments and a cattle tooth fragment, while pair 3.5 yielded a small quantity of medium and large mammal rib and vertebral bone fragments.…”

A relutância das populações rurais às influências orientalizantes do 1º milénio a.C.: Evidências zooarqueológicas na margem direita do médio Guadiana, Portugal

“…Podem também ser queimados como consequência de actos rituais (TCHESNOKOV 1995) e, nesse caso, costumam apresentar elevados graus de calcinação. As marcas de manipulação térmica podem ainda estar relacionadas com práticas utilitárias como a limpeza do local de habitação (MEIGNEN et al 2000), ou actividades relacionadas com a extracção de gordura (OUTRAM 2002), práticas culinárias (GIFFORD-GONZÁLEZ 1993;PEARCE & LUFF 1994;MONTÓN-SUBÍAS 2002) e, em casos etnográficos e de sítios pré-históricos, poderão estar relacionados com a utilização de ossos de animais como combustível para estruturas de combustão (COSTA 2016;COSTAMAGNO et al 1999;2005;THÉRY-PARISOT 2002;THÉRY-PARISOT et al 2005;VILLA et al 2002;YRAVEDRA et al 2005).…”