Preliminary results on the erosion of the northeastern cliff near the fortress of Orgame / Argamum

Abstract

To get a more realistic picture of urban development of ancient city Argamum, from the colonization era to Justinian’s time, it is necessary to know the historic land shape as closely as possible. This study aims to reconstruct the outline of the cliff taking into account the scenario of a collapse generated by earthquake and the scenario of water erosion, initially by the Black Sea, followed by that of Lake Razelm after the deposit of sand seams. The method applied is based on simulating the evolution of erosion, based on existing data from the site of Argamum, using a calculation method applied in the design of buildings that encompass land slopes, which approximate their stable slope section, and a formula that assessing the necessary time erosion of the material resulted from cliff collapses. What we can state is that the shore – in the 18 meters high area roughly adjacent to the late Roman wall – has eroded with ~ 35 m ± 4 m in 1500 years and has eroded by an average of 16 ± 4 m in the period 500 BC - 500 AD. In the area where the cliff is less high, about 3 meters high, the predominant erosion is the long-term one, and the collapses did not play a significant role. In this area the erosion in 1500 years is about 24 m ± 2 m and the contour of the shoreline was 35 m ± 4 m more extended 2500 years ago.