Piccole fosse e “depositi strutturati” del Neolitico Medio B in Sardegna (4500-4000 cal. BC)

SMALL PITS AND "STRUCTURED DEPOSITS" DURING MIDDLE NEOLITHIC B IN SARDINIA (4500-4000 CAL. BC) - During the last decade, the researches about some sites of the San Ciriaco facies (4500-4000 cal. BC), especially in Central-Western Sardinia (fig. 1), led to identify a particular diversification of the dug-out structures, in terms of morphology, size, type of contents and filling processes (Soro, Usai 2009; Lugliè et alii, in press; Fanti et alii, in press). The aim of this paper is to reflect on the use of some dug-out structures during this period, in particular on the small pits, with a specific attention to the role of the functional analysis of the artifacts contained in the pits as a key to the interpretation of the function of the pits themselves. On the one hand, some Middle Neolithic B sites (San Ciriaco-Terralba, Su Mulinu Mannu-Terralba, Cuccuru is Arrius-Cabras, OR) are characterized by medium-large size pits with fragmentary and scattered faunal, ceramic and lithic remains, resulting from a generic repeated but not ordered activity linked to refuse disposal (Santoni et alii 1997; Sebis et alii 2012, 498; Lugliè et alii in press). On the contrary, in other sites (as Gribaia-Nurachi, OR, and, in part, Bau Angius-Terralba, OR), there are small pits, generally having a subcircular or subelliptic shape, with a diameter and depth of about 20-40 cm, filled with selected and differentiated materials, which are almost intact or preserved for a good portion of their original morphology (fig. 2, a) (Lugliè 2003; Soro , Usai 2009; Fanti et alii in press). Different types of structures can be distinguished: - small pits containing groups of pottery vessels with whole, half or ¾ preserved profiles; the vessels were stacked one inside another, or turned upside down and stacked one upon another (fig. 2, a-b); sometimes, sporadic faunal or malacological remains, almost complete bone tools and/or ground stone tools were associated to pottery containers; - small pits containing malacological remains; - small pits containing obsidian and/or flint tools. The state of conservation, the intentional separation of different kinds of artefacts and the structured deposition of these ones reflect a sequence of intended and repeated actions. Specially, the detailed analysis of contents of “type a” small pits (filled with pottery vessels), led to identify a recurrent association of vessel morpho-types, whose combination seems to constitute a “set” of containers, that have been used together and then deposited. In order to understand the function of pottery vessels in the small pits and, consequently, to obtain some clues about the function of the same dug-out structures, we focused our research on the analysis of morphodimensional features of vessels, on use-wear of ceramic surfaces, and on chemical analysis of absorbed organic residues in pottery. The results of this integrated methodological approach revealed that vessels were used to contain and process animal and vegetal foods before deposition in pits (Fanti et alii 2016). The features of the small pits of Middle Neolithic B in Sardinia (morphology and dimensions, separation or association of different kinds of artefacts and faunal remains, structured deposition, use of vessels as identified by functional analysis) suggest a codified, shared and possibly symbolically invested behavior. Nevertheless, based on the archaeological and ethnographic literature, different interpretations can be made about function of these small pits, and about cultural and social implications underlying in behaviors of Middle Neolithic B societies. All different interpretations have to be discussed in synchronic and diachronic relationship with available data on the function of dug-out structures and small pits used by other Neolithic groups in Mediterranean and centralsouthern Europe.