The Survey of Thisve, Geoarchaeological survey 2011
Survey: Geoarchaeological survey
Geoarchaeological fieldwork in 2011–12 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 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±6 ka BP by Optically Stimulated Luminescence. These are covered by 2–3 m of slope deposits (dated at 54±4 ka BP by OSL) capped by a palaeosoil that may have formed prior to 28 ka BP and was still active at the contemporary surface at c 5400 BP (determined by 14C AMS). This well-developed palaeosoil surface was truncated and buried by slope deposits up to 6 m thick. A minor palaeosoil was formed c. 2 m below the present surface. The Plain of Thisbe was stable from at least 2200 BP but, as a component of a poorly drained enclosed basin (a polje), subject to major seasonal inflows of water, a challenge to the sedentary farmer. Study in 2012 focused on detailed description of these palaeosoils in order to reconstruct palaeo-environmental conditions during soil formation, and on dating the soils to assess the timing of intense local erosion. Three samples were taken for 14C age-estimation. A ground-penetrating radar survey of part of the basin aimed to distinguish between basin matrix, this early earthwork, 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. 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.
Active in 2011.
Dunn, Dr Archibald W.