The ancient harbor of Magdala (Kinneret lake, Israel): its space time history on the basis of geological evidence

Thanks to the collaboration between geologists and archeologists the ancient harbors geosciences have increasingly developed during the last years and the interest in this discipline is still quickly growing, providing important information on Holocene coastal stratigraphy, palaeogeography and sea-level changes (Morhange et al., 2001; Sivan et al., 2001; Brückner et al., 2002; Marriner et al., 2005; Marriner and Morhange, 2007; Goodman et al., 2009; Goiran et al., 2010; Algan et al., 2011). Indeed, the study of the geological records contributes significantly to define the space-time evolution of the palaeodepositional environments where the ancient harbors developed, and also strongly supports the archeological evidences (Marriner and Morhange, 2007). In the Mediterranean area recent examples of these integrated studies include the ancient harbors of Marseille (Morhange et al., 2003), Rome (Giraudi et al., 2009; Goiran et al., 2010), Beirut (Marriner et al., 2008, in press), Sidone (Marriner and Morhange, 2005; Marriner et al., 2006), Tyre (Marriner et al., 2008, in press), Caesarea Marittima (Reinhardt et al., 1994, 1998; Reinhardt and Raban, 1999), Troy (Kraft et al., 2003) and Liman Tepe (Goodman et al., 2009; Feuser, 2010). These studies significantly improved the knowledge about the historical evolution of harbor engineering especially during the Roman age (Franco, 1996) and highlighted the strict relationships existing among harbor evolutive phases (e.g. foundation, siltation, abandonment), natural events (e.g. sea-level variations, earthquakes) and, obviously, archaeological history. Most of these studied harbors are located in delta plain areas, in front of the sea, while no interdisciplinary studies on lacustrine ancient harbors are available to date. Around the Sea of Galilee (also known as Tiberias or Kinneret Lake, north Israel; Fig. 1A-B), site of great importance for the history of Jews, Christians and Muslims, twelve roman to byzantine jetties and small piers have been described at altitude of about 212 ± 1 m bsl (Mendel-Nun, 1987; Raban 1988). Recent excavations at the ancient city of Magdala (De Luca, 2008, 2010, 2011; Lena, 2012; see Figs. 1 and 2 for location) have unearthed a harbor structure with four mooring stones (Fig. 3) at an altitude of 208.32 m bsl, suggestive of a higher lake-level in respect to the previous hypothesis reported by Mendel-Nun (1987). The discovery of this ancient harbor area, ranging in age from late Hellenistic to middle Roman period (ca. 167 BC-270 AD), has major implications for the archaeological history of the Sea of Galilee surroundings, that were inhabited and crossed by many different civilizations since ancient times (De Luca, 2009). In this report we present the preliminary results of the interdisciplinary study performed on the archaeological site, within the Magdala Project (http://www.magdalaproject.org/WP/), in order to reconstruct the depositional space-time evolution of the Magdala ancient harbor, located on the northwest side of the Sea of Galilee (Fig. 1A) between the cities of Tiberias and Capharnaum. The study of the sedimentary deposits on which the harbor structures rest and those that mark its siltation and its subsequent abandonment has been integrated with the archaeological evidences. This integration has allowed drawing a preliminary picture of the harbor history and further supplying indications about lake-level fluctuations and changes in sediment supply during the last centuries.