Early Neolithic Obsidian Trade in Sardinia: The Coastal Site of Santa Caterina di Pittinuri (Cuglieri - OR) Archaeological Institute of America Annual Meeting San Diego, CA, January 4th-7th, 2007
Robert H. Tykot1 & Peter Karellas, University of South Florida; Carlo Tozzi, Università di Pisa Introduction
Lithic Finds at Santa Caterina
Results
While already well-documented that obsidian was widely traded in the central Mediterranean in the Neolithic period (ca. 6000-3000 BC) (Figure 1), there are still few studies of the earliest period of its usage. At Santa Caterina di Pittinuri (Cuglieri - OR), located on the western coast of Sardinia (Figures 2-3), more than 3000 obsidian and chert artifacts were collected, dating to the Cardial Impressed Ware period. In the study presented here, a large assemblage of the obsidian artifacts from this site were analyzed to determine which sources of Monte Arci obsidian were used, and how the selection of obsidian at this open-air coastal site compares with the three inland Cardial or Filiestru phase Early Neolithic rock-shelter or cave sites previously tested in Sardinia.
A total of 3090 artifacts were collected in a systematic way, specifically samples of all sizes in order to study the selection of different materials for different purposes, with 45% (1390 pieces) made of obsidian (Figure 7). The basic observation of fractured and pseudo-retouched edges is thought to result from the processing of animal materials. Virtually all of the obsidian artifacts are small (Figure 8), and lack any cortex, in other words representing advanced stages of lithic production. The collection includes 17 cores, with 5 produced by direct percussion and 12 using bipolar percussion. The typical core found was less than 2 cm in any dimension. Overall, the size and type of the lithic artifacts clearly represent advanced stages of lithic production, with primary extraction/production occuring elsewhere (Figure 9). The Santa Caterina di Pittinuri collection studied here compares well with surface finds from the nearby site of Su Paris de Sa Turre (Lugliè 1999), and with excavated finds at Su Carroppu di Sirri-Carbonia (Atzeni et al. 2004; Lugliè et al. 2007) and other Cardial Early Neolithic sites in Sardinia.
As in many XRF studies, the most useful elements for sourcing were Rb, Sr, Y, Zr, and Nb. A simple plot of Sr vs. Nb (Figure 11) shows clear differences between the three major Monte Arci subgroups (A, B, C). Distinction among the Sardinia B subsources is not as clear, but it appears that all but two of the 26 artifacts assigned to the SB subgroup are specifically of type SB2. % 100
The obsidian assemblage
Figure 7. The surface area north of Torre Pittinuri, where obsidian artifacts may still be observed today.
Figure 8. The artifacts collected in 1991-1992 are only a fraction of those still visible on the surface at Santa Caterina di Pittinuri. Figure 9. Sample of the small secondary production artifacts found at Santa Caterina
Analytical Methods
The Site of Santa Caterina di Pittinuri
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96
12
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63 26
Lipari Palmarola Sardinia C Sardinia B2 Sardinia B1 Sardinia A
Arene Candide
Paduletto
Querciolaia
Isola del Giglio
La Scola
Cala Giovanna
Strette
Lumaca
Pietracorbara
Su Carroppu
Filiestru - EN
Filiestru - Filiestru
0
Figure 12. Comparison of Santa Caterina with other Early Neolithic sites tested. At top are numbers of samples tested for each site.
All artifacts were first studied visually, specifically recording transparency, shininess, and other visual properties, and density was also measured. These simple, non-invasive measurements have previously been shown to be fairly successful in studying general source usage patterns for large artifact assemblages (Tykot 1996). In this study, however, the small size of the artifacts made it difficult to distinguish subsources macroscopically. Figure 6. Monte Arci (Sardinia) source consists of several chemically distinct outcrops, labelled SA, SB1, SB2, and SC (Tykot 1997).
A random selection of 35 artifacts from Santa Caterina were thus analyzed by energy-dispersive XRF using a new, portable ElvaX X-ray fluorescence (XRF) spectrometer (Figure 10). This instrument, run by Michael Glascock and Jeff Speakman at the University of Missouri, is one of several new instruments being tested for applications in the Mediterranean. In this study, the area on each artifact tested was about 3x4 millimeters, with results obtained for K, Ti, Mn, Fe, Zn, Ga, Rb, Sr, Y, Zr, Nb, Pb, and Th. Calibration was accomplished by using a special set of Mediterranean geological samples previously collected and studied by XRF and NAA (Tykot 1997; 2002c; 2004a).
The visual study and chemical analysis of more than 200 obsidian artifacts from Santa Caterina di Pittinuri provides a statistically significant dataset for reconstructing the usage of obsidian at the beginning of the Neolithic and may specifically be used to address socioeconomic systems at that time. The results obtained for Santa Caterina di Pittinuri strongly follow the general pattern of Monte Arci subsource usage previously found for inland Early Neolithic sites, specifically Grotta Filiestru (Mara-SS) and Sa Corona (Monte Majore-SS) in northwestern Sardinia (Tykot 1996, 2002a, 2002b), and most recently, Su Carroppu (Sirri-CA) in southwestern Sardinia (Lugliè et al. 2007) (Figure 12). In particular, the use of all Monte Arci subsources at the coastal site of Santa Caterina, especially type SB2 obsidian, fully supports an interpretation of down-the-line exchange during the Early Neolithic, both within Sardinia and from Sardinia to Corsica, the Tuscan archipelago, and mainland Italy. At the inland site of Grotta Filiestru, the earlier study also indicated a chronological change in the importance of the Monte Arci subsources, with an increase in type SC over the course of the Neolithic, and this pattern was also documented at other sites in Sardinia and Corsica. In southern France, however, type SA obsidian was specifically selected over the other subsources, suggesting a different exchange system. Further detailed lithic and use-wear studies which integrate these results with the archaeological context in which the artifacts are found, along with potential selection of specific subsources for certain tool types, will provide a more enhanced understanding of the obsidian chaîne opératoire and the socioeconomic system which existed in early agricultural times (Tykot 1999; 2004b; Lugliè 2004; Tanda et al. 2006) (Figure 13). Further studies of open-air sites in coastal areas would provide significant information about prehistoric Sardinia and its connections with the central Mediterranean (Figure 14).
References
Figure 4. View from the south of the Pittinuri tower, and the small cove and shoreline area suggesting easy maritime trade connections
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Interpretations and Discussion
Figure 2 (left). Santa Caterina is located on the west coast of Sardinia, in the province of Oristano. The archaeological finds specifically come from the area immediately north of the medieval tower of Pittinuri (Figure 3, above).
Located just to the north of the coastal town of Santa Caterina (Figure 4), and the medieval tower of Pittinuri (Figure 5), lithic materials in flint and obsidian were found spread over a large, fairly flat area very close to the coast, during a survey in 1991-1992 led by Carlo Tozzi. This undeveloped area still has a significant amount of material exposed, as observed during a visit by Tykot in 2006. Detailed study of the archaeological materials from Santa Caterina di Pittinuri has resulted in the interpretation of the site as a workshop area for producing microliths, and preparing tools for hunting and other purposes (Tozzi, forthcoming). This is supported by the absence of pieces with any cortex, and of formal tools. The obsidian at this site, like all others in Sardinia, would have come from Monte Arci, about 40-45 km to the southeast (Figure 6).
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Figure 11. Simple plot of strontium (Sr) versus Niobium (Nb) shows clear distinction between the major SA, SB, and SC subsources at Monte Arci.
Summary of results ¾ 6 SA 17.1% ¾ 2 SB1 5.7% ¾ 24 SB2 68.6% ¾ 3 SC 8.6%
Santa Caterina
Su Carroppu
63 10
40
Filiestru
Monte Arci
26
Sa Corona - Filiestru
Sa Corona
20
60
Santa Caterina
¾ 843 debris (60.6%), with 80% of these under 12 mm in length, all less than 25 mm ¾ 226 non-retouched (16.3%) ¾ 204 flakes (14.7%), representing both direct and bipolar percussion ¾ 87 pieces (6.3%) with pseudoretouch, including 22 blades/micro-blades ¾ 17 cores (1.2%), 5 with direct percussion, 12 bipolar percussion ¾ 13 other tools (0.9%), including 11 geometric shapes, and 2 scrapers
Figure 1. Obsidian sources and archaeological sites with tested artifacts, showing the general distribution during the Neolithic in the central Mediterranean.
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Figure 5. View of the relatively flat surface area, north of the Pittinuri tower, where Early Neolithic artifacts have been recovered
Figure 10. Portable XRF instrument used in this study. This and other portable spectrometers are currently being tested on the other Mediterranean subsources.
Lugliè, C. 1999. Materiali del neolitico antico da Su Paris de Sa Turre a S. Caterina di Pittinuri (Cuglieri-OR). Quaderni 15: 3-27. Lugliè, C. 2004. Modalita` di acquisizione dell’ossidiana del Monte Arci nel Neolitico. In P. Castelli, B. Cauli, F. Di Gregorio, C. Lugli è, G. Tanda, C. Usai (Eds.), L’ossidiana del Monte Arci nel Mediterraneo: recupero dei valori di un territorio, Atti del Convegno Internazionale, Oristano e Pau, 29 novembre-1 dicembre 2002, Tipografia Ghilarzese, Ghilarza, pp. 47-70. Lugliè, C., F.-X. Le Bourdonnec, G. Poupeau, E. Atzeni, S. Dubernet, P. Moretto & L. Serani. 2007. Early Neolithic obsidians in Sardinia (Western Mediterranean): the Su Carroppu case. Journal of Archaeological Science 34: 428-439. Tanda, G., C. Lugliè, S. Meloni, M. Oddone, G. Poupeau, F.-X. Le Bourdonnec. 2006. L’ossidiana del Monte Arci: nuove acquisizioni sullo sfruttamento e sulla circolazione alla luce dei dati archeometrici. Materie prime e scambi nella Preistoria italiana. Atti della XXXIX Riunione Scientifica dell’Istituto Italiano di Preistoria e Protostoria, Firenze, 25-27 Novembre 2004, pp. 461-481. IIPP, Firenze. Tozzi, C. In press. L’industria litica in ossidiana dei siti neolitici di Santa Caterina di Pittinuri e Torre Foghe sulla costa occidentale della Sardegna. Tykot, R.H. 1996. Obsidian Procurement and Distribution in the Central and Western Mediterranean. Journal of Mediterranean Archaeology 9(1): 39-82. Tykot, R.H. 1997. Characterization of the Monte Arci (Sardinia) Obsidian Sources. Journal of Archaeological Science 24: 467-479. Tykot, R.H. 1999. Islands in the Stream: Stone Age Cultural Dynamics in Sardinia and Corsica. In R.H. Tykot, J. Morter & J.E. Robb (eds.), Social Dynamics of the Prehistoric Central Mediterranean. London: Accordia Research Institute, University of London. Accordia Specialist Studies on the Mediterranean 3: 67-82. Tykot, R.H. 2002a. Geochemical Analysis of Obsidian and the Reconstruction of Trade Mechanisms in the Early Neolithic Period of the Western Mediterranean. In K. Jakes (ed.), Archaeological Chemistry. Materials, Methods, and Meaning. Washington, DC: ACS Symposium Series 831, 169-184. Washington, DC: American Chemical Society. Tykot, R.H. 2002b. New Approaches to the Characterization and Interpretation of Obsidian from the Mediterranean Island Sources. P.B. Vandiver, M. Goodway, J.R. Druzik & J.L. Mass (eds.), Materials Issues in Art and Archaeology VI. Warrendale, PA: Materials Research Society Proceedings 712: 143-157. Tykot, R.H. 2002c. Chemical Fingerprinting and Source-Tracing of Obsidian: The Central Mediterranean Trade in Black Gold. Accounts of Chemical Research 35:618-627. Tykot, R.H. 2004a. Scientific Methods and Applications to Archaeological Provenance Studies. In M. Martini, M. Milazzo & M. Piacentini (eds.), Physics Methods in Archaeometry. Proceedings of the International School of Physics “Enrico Fermi” Course CLIV, 407-432. Bologna, Italy: Società Italiana di Fisica. Tykot, R.H. 2004b. L’esatta provenienza dell’ossidiana e i modelli di diffusione nel Mediterraneo centrale durante il Neolitico. In L’ossidiana del Monte Arci nel Mediterraneo: recupero dei valori di un territorio (a cura di P. Castelli, B. Cauli, F. Di Gregorio, C. Lugliè, G. Tanda & C. Usai), pp. 118-132. Tipografia Ghilarzese, Ghilarza. 1
The Chaîne Opératoire Reduction Modification
Production Use
Re-use
Deposition Acquisition (extraction) Transport Exchange
Figure 13. The study of ancient socioeconomic systems requires more than just attributing artifacts to specific geological sources .
Figure 14. Is it not likely that there was an Early Neolithic settlement in the same beautiful area as modern Santa Caterina? Perhaps a modern survey will find one!
Department of Anthropology, University of South Florida, Tampa, FL 33620; 813 974-7279; email:
[email protected] 