THISBE (KASTORION) - 2012

Thisbe (Kastorion). A. Dunn (BSA/Birmingham) reports on the 2012 study season and palaeo-environmental survey of the Thisbe basin, conducted in collaboration with the 23rd EBA.

A complete photographic survey and masonry study was made of all structures recorded around the urban site of Thisbe/Kastorion, and the ancient, multi-period water-management features of the Thisbe basin.

Geoarchaeological fieldwork aimed: to describe key elements of the sedimentary fill of the basin; to improve the reliability of the geochronology for the fill; and to improve understanding of the central waterworks near Thisbe. The sedimentary succession is well exposed in a major quarry (100 x 50m, up to 14m deep) at the south side of the basin. Up to 6m of alluvial floodplain deposits exposed at the base of the sequence are dated at 73+/-6ka BP by Optically Stimulated Luminescence. These are covered by 2-3m of slope deposits (dated at 54+/-4ka BP by OSL) capped by a palaeosoil that may have formed prior to 28ka BP and was still active at the contemporary surface at ca 5400 BP (determined by 14C AMS). This well-developed palaeosoil surface was truncated and buried by slope deposits up to 6m thick. A minor palaeosoil was formed ca 2m below the present surface; archaeological evidence demonstrates that the present surface has been stable since at least 2200 BP. Current fieldwork focused on detailed description of the (palaeo-)soils in the sequence in order to reconstruct palaeo-environmental conditions during soil formation, and on dating the soils to assess the timing of intense local erosion (as evidenced by the rapid burial of the major palaeosoil). Three samples were taken for 14C age-estimation.

The visible part of the north-south stone-lined earthwork across the centre of the Thisbe plain is probably Hellenistic. However, sediments exposed in the archaeological trench may indicate that the east flank of this structure was set in a (Mycenaean?) earthwork which could have its base 3-4m below the present floodplain surface. This earthwork was probably rebuilt in the Ottoman period. This structure may have served a double function as a dam-causeway, containing the temporary lake at the west side of the dam, and perhaps helping to irrigate the lands to the east through controlled inundation. The north part of the structure was later used as the base of a major (Frankish-Ottoman?) irrigation channel that supplied the lower lands on either side of the dam. The incised stream directly west of Thisbe contains dam structures built or repaired during the Mycenaean, Archaic-Hellenistic, Middle Byzantine-Frankish, Ottoman and early modern periods. These structures feed the irrigation systems around Thisbe that water the lower slopes of the extensive alluvial fans that extend into the basin. They likely served to divert floodwaters for irrigation, including storage in cisterns.

The Alyki saltmarsh was re-sampled for pollen analysis. A ground-penetrating radar survey of part of the basin aimed to distinguish between basin matrix, the earthen phase(s) (probably Bronze Age-Archaic) of one of the ancient water-management features of the basin, and a colluvial fan that is submerging one of these earthworks and the floodplain. Linear features identified on the north side of the basin must be buried sections of the Classical-Hellenistic dam- causeway previously planned with test excavation on the south side. The survey results indicate that its façade is preserved in many places, that it contains sluice gates, and that it adjoins the earthen embankment phase(s) visible at ground level.