Figure 8

Geographic maps showing three evolutionary stages of the lagoon, in relation to Portus Pisanus as documented by historical sources and archaeological data. Maps were produced by integrating stratigraphic (cores and trenches) and geomorphological data (Pranzini, 2007) with historical cartography. Dots indicate cores used to draw the maps (key cores are highlighted by red dots). The modern shoreline is depicted on each map for reference. The grey arrow indicates the direction of the predominant wind (Libeccio). (A) Roman period - a wide lagoon basin, hosting Portus Pisanus as mentioned in literary sources; (B) late Middle Ages - the accretion of arcuate beach ridges, belonging to the Arno Delta strandplain, led to an increase in the degree of confinement of the lagoon basin. Construction of the maritime harbour of Livorno in a seaward position with respect to the lagoon; (C) 17^th century AD - the rapid accretion of strongly arcuate sets of beach ridges led to the siltation of the lagoon that was transformed into a wetland, physically detached from the Ligurian Sea. Portus Pisanus abandonment and expansion of the fortified maritime harbour of Livorno.