Geoarchaeology and phytolith studies
The 2016 excavation campaign at Sissi was complemented by a preliminary geomorphological survey undertaken in the valleys debouching to the east and west of the Kephali Hill. This survey was carried out by Dr. Simon Jusseret (University of Texas at Austin, USA, and UCLouvain) and Prof. Mark Macklin (Aberystwyth University, now at University of Lincoln, UK) between July 4 and 8, 2016. In addition to surface reconnaissance of the valley landforms, two cores (Si1, Si4) were put down in the valley to the southwest of the Kephali (Fig. 1-5). They were collected using a Sedidrill percussion corer (generously provided by the French School at Athens) and are currently stored in our Agios Nikolaos storeroom in 50-cm long transparent PVC tubes. The two cores, drilled to a depth of 6 m (Si1) and 7 m (Si4), exhibit a similar depositional sequence starting with an alternation of granule-size gravelly deposits and (sandy) silty clay (core base to a depth of 3.00/3.50 m), followed by a clayey silt package (3.00/3.50 m to c. 2.00 m), gravelly in Si1. In both cores, the clayey silt unit is capped by a compact clayey silt layer (c. 2.00 m to 1.50 m) and a dusty silt deposit (upper 1.50 m). The compact clayey silt layer may represent a particularly dry episode in the Selinari catchment’s depositional history; elucidating the date of this event will therefore represent a prime objective for future geomorphological investigations. Two charcoal samples were isolated in the compact clayey silt layer for future radiocarbon analyses.
Fig. 1: Location of cores Si1 and Si4.
Fig. 2: Gwendoline Guillaume and Justine Simons coring at the location of Si1.
Fig. 3: Benjamin Tresca, Pierre Verstegen and Prof. Mark Macklin extract core Si4.
Fig. 4: Transparent PVC tube containing a 50 cm-long undisturbed sediment sample.
Fig. 5: Opening of the PVC tubes. Combining samples collected at different depths allows reconstructing the Selinari River’s Late Pleistocene and Holocene depositional history.
In parallel to these off-site geomorphological investigations, sediment samples are routinely collected on site for phytolith analyses. Phytoliths represent microscopic silica bodies produced within and between living plant cells. Following plant death and decay, phytolith are typically deposited into soils and sediments where they become part of the paleobotanical record (Piperno 2006: 5, 21). When found in archaeological contexts, phytoliths can therefore be assumed to be directly associated with the archaeological site (i.e. introduced by human and/or animal activities), although external depositional factors (e.g. wind) should likewise be considered (Rosen 1999). Phytoliths represent one of the most durable plant fossils and are therefore commonly observed in archaeological sediments where other types of plant remains (e.g. charcoal, seeds) may not be preserved. The production of phytoliths is controlled by a variability of factors including growing conditions (nature of the soil, climate, water availability, etc.) and, most importantly, taxonomic affinity (not all plants produce phytoliths). These attributes mean that the analysis of phytoliths preserved in archaeological sediments can provide valuable information on the use of space, diets, agricultural practices, climate changes and construction technologies at ancient sites. They can also offer important clues to the formation mechanisms of archaeological deposits (e.g. abandonment, collapse, destruction).
Sediment samples originating from Late Minoan IIIB (c. 1300-1200 BC) contexts are currently under study by Dr. Simon Jusseret in the Laboratory of Environmental Archaeology of the University of Texas at Austin (USA) under the supervision of Prof. Arlene Rosen. Preliminary observations already identified “echinate spheroid” phytoliths (Fig. 6) in Building CD (space 4.15), providing unique evidence for the presence of palm at Sissi. Although palms are a well-known motif in Minoan and Aegean iconography, their archaeological visibility is very low. As a matter of fact, the phytoliths recovered from Building CD may represent the first direct evidence of palm use in Minoan Crete, adding to similar recent findings in Tiryns (Vetters et al. 2016) and Thera (Vlachopolous and Zorzos 2014). Whether the Sissi evidence implies that the native Cretan date palm (Phoenix theophrasti) – today mostly scattered along the coasts of the island as isolated tufts (Rackham and Moody 1996: 65) – was growing in the Sissi landscape toward the close of the Bronze Age remains to be seen. Furthermore, it is as yet difficult to associate the presence of palm phytoliths at Sissi with specific uses (e.g. food, basketry, matting, construction) since echinate spheroid phytoliths are produced by different parts the plant (fruit, leaves, stems, etc.) (Piperno 2006: 37).
Fig. 6: Palm phytolith from Building CD, space 4.15.
References
Piperno, D.R. 2006. Phytoliths: A Comprehensive Guide for Archaeologists and Paleoecologists. Lanham: AltaMira Press.
Rackham, O, Moody J. 1996. The Making of the Cretan Landscape. Manchester: Manchester University Press.
Rosen, A.M. 1999. Phytolith analysis in Near Eastern archaeology. In: The Practical Impact of Science on Near Eastern and Aegean Archaeology, S. Pike, S. Gitin (eds), 9-15. Wiener Laboratory Monograph 3. London: Archetype Books.
Vetters, M., Brysbaert, A., Ntinou, M., Tsartsidou, G., Margaritis, E. 2016. People and plants. Piecing together archaeological and archaeobotanical data to reconstruct plant use and craft activities in Mycenaean Tiryns. Opuscula 9: 93-132.
Vlachopoulos, A., Zorzos, L. 2014. Physis and Techne on Thera: reconstructing Bronze Age environment and land-use based on new evidence from phytoliths and the Akrotiri wall-paintings. In: Physis. L’environnement naturel et la relation Homme-milieu dans le mond égéen protohistorique. Actes de la 14e Rencontre égéenne internationale, Paris, Institut National d’Histoire de l’Art (INHA), 11-14 décembre 2012, Touchais, G., Laffineur, R., Rougemont, F. (eds), 183-197. Aegaeum 37. Leuven, Liège: Peeters.
Dr. Simon Jusseret
The University of Texas at Austin