The Excavation Project consisted of systematic archaeological research (excavations and surveys) on the Deserted Islands' group to the north of Alonnissos, Northern Sporades (Greece). The project was undertaken by the Ephorate of Palaeoanthropology - Speleology of the Ministry of Culture under the direction of Dr Adamantios Sampson, Ephor of Antiquities. The project's purpose was to clarify the prehistoric occupation sequence in the area of the Northern Sporades, a chain of islands off-shore to the east of the Thessalian plain.

The research intended to fill a gap in our knowledge about human activity in the area from Late Pleistocene to Early and Middle Holocene, with emphasis on the pre-pottery stage; relevant evidence had already come to light in previous short-term and short-scale local projects. The purpose was to recover new data, which would give hints on the identity of the early communities, their management of the ecosystem, their subsistence strategies and their contacts with the Greek mainland and Asia Minor. The project also intended to enrich knowledge on the palaeoenvironment, and to detect phenomena such as sea level changes, regional palaeogeomorphology, climatic conditions and local ecosystem idiosyncrasies (flora and fauna). For that purpose a broad team of scientists (archaeologists and archaeological scientists) was recruited, along with a competent technical support staff, who undertook the difficult task of carrying out the research in the remote and inhospitable area in question, where fieldwork and camping proved to be very demanding.

The research was purely systematic and scientific and did not involve any rescue works. First and basic project's activity was the excavation of the Cave of Cyclopes, an impressive cave at the SE end of Gioura, one of the northern islands of the group. The cave was investigated in six trenches (A, B, Γ, Δ, Ε and Ζ) and yielded thick deposits dated from the Early Holocene to the Late Roman period. A brief description of the deposits per period is following:

- Roman finds were scarced all over the surface and the top layers and contained mostly oil-lamps decorated in relief or inscribed, implying that the cave served as a sanctuary around 2nd-3rd c. A.D. The cave was situated at the naval trade route of the Athenian merchant ships to the wine markets of Macedonia and Thrace.
- A few ceramics dated to the Hellenistic and classical periods were selected from the deep interior of the cave, suggesting that its use at the time was occasional.
- Scattered Bronze Age material was found within the upper Neolithic deposits, such as poor Late and Early Bronze Age pottery.
- All the above layers are underlied by a thick Neolithic deposit, corresponding to two phases: Late Aegean Neolithic Ib and Early Neolithic II. The layer contained exceptional painted wares, such as the red-on-white ware of Early Neolithic II with complicated canvas motifs and weaving inspired designs, as well as the white-on-dark and matt-painted wares of Late Neolithic, whose broad expanse throughout the mainland and the Aegean is hence verified. The Neolithic material was enriched with the unexpected recovery of a small-sized sherd from a coarse close-shaped vase bearing incised unidentifiable symbols. It is possible that it echoes evidence on an Aegean Neolithic 'script' or 'proto-script', a very fashionable subject of discussion in Greece, after similar finds in Kastoria lake, East Macedonia.

- The main appeal of the excavation was the discovery of thick pre-pottery layers. The C14 datings assigned the material to the Early Holocene, more specifically to the 9th-7th mil. B.C., which placed Gioura at a contemporary stage to Franchthi Early Holocene levels; however it was the first time the existence of an Aegean Mesolithic culture was revealed in full stratigraphy. Gioura Mesolithic chipped stone industry used local flint and Melian obsidian, which suggests that the trade/exchange network for obsidian exploitation had been set up at such an early stage. During the Early Holocene, the obsidian microliths from Gioura (trapezoidal, semi-crescents) find affiliations only in south Antalya caves (Turkey). The Greek mainland shares no relevant evidence, since the Argolid material, for example (Franchthi cave, Klisoura rock shelters), which is the best studied, is far different in the adjacent area. Evidence of diversity between Gioura and mainland Greece is also supported by the cranial remain of a homo found in the lowest layer of the cave of Cyclops, and was named as the "Aegean Mesolithic homo"; the Mesolithic human skulls from Theopetra cave show strong anatomical differences suggesting probably the co-existence of a "mainland homo type".

Painted jar of the Middle Neolithic period

The cave of Cyclops deposits yielded a rich collection of worked bone tools, such as fish hooks of various sizes and shapes, ranging from the U-shaped hook type to the pinpointed implement for big fishes. A mass concentration of fish bones, sea shells, land snails, mammal bones and bird remains imply that Gioura was occupied on a seasonal basis by hunter-gatherers specialized in fishing and bird hunting. The mobile populations seem to have developed high skills on both tasks; it is likely that people of the time follow the movements of birds and fish, while at the same time they enrich their diet with game, seafood and land snails.

The correlation between their temporary occupation of the cave and the itineraries of the migratory birds and fish also implies a well-developed seafaring activity and a good knowledge of the winds and climatic conditions to secure their voyages.

Stratigraphy inside the cave (Trench C)

The stratification of the cave of Cyclopes' Mesolithic deposits provided the study of C14 with a new good implement for the development of the method, the dating of other than charcoal organic materials. Trial C14 dating on animal and fish bones, shellfish and land snails have taken place in the Laboratory of Archaeometry in the Nuclear Centre of "Demokritos" in Athens, and have been certified by measurements of C13 at the Institute of Environmental Physics, University of Heidelberg (Germany). Both results have been correlated with the charcoal C14 dating from the very same strata. Dating from the above 'new' materials appear to have a standard divergence of some hundreds of years from the charcoal samples, which is due to the different quantities of oxygen that the plants (charcoal), shellfish, land snails and mammals absorbed. The correlation can be very useful for sites where no charcoal is found; bones or shellfish, for example, can then be dated instead on the basis of the data provided by the cave of Cyclopes C14 chronology, where the divergence has been statistically studied.

The excavation occurred parallel to a survey investigation on Gioura and the adjacent islands. A few more caves located on the island of Gioura have yielded evidence of the same Mesolithic culture with the cave of Cyclops, while abundant Middle Palaeolithic and Neolithic material was also collected. A systematic underwater research all along the seashore of Gioura resulted in the location of several underwater caves around the depth of 20-30 m. below sea level, which would have been dry and probably occupied during the Mesolithic. No evidence of human occupation was traced though, only due to the difficulties posed by underwater investigation.

Dr Adamantios Sampson, Ephor of Antiquities