The Tiber river delta plain (central Italy): Coastal evolution and implications for the ancient Ostia Roman settlement

Abstract

Geomorphologic, stratigraphic, faunistic, palynological and carbon isotope analyses were carried out in the area of the Tiber river mouth. The results depict a complex palaeoenvironmental evolution in the area of the Roman town of Ostia, ascertain the changes of the Tiber river delta over the last 6000 years and support a re-interpretation of some archaeologic issues. The wave-dominated Tiber delta evolved through three distinct phases. In the first step (5000-2700 yr BP) a delta cusp was built at the river mouth, which was located north of the present outlet. Subsequently (2700-1900 BP), an abrupt southward migration of the river mouth determined the abandonment of the previous cusp and the progradation of a new one. The third step, which is still in progress, is marked by the appearance of a complex cusp made up of two distributary channels. The transition from the first to the second evolution phase occurred in the seventh century BC and was contemporary to the foundation of Ostia, as suggested by historical accounts. However, the oldest archaeological evidence of the town of Ostia dates to the fourth century bc, when human activity is clearly recorded also by pollen data. We suggest that the first human settlement (seventh century bc) consisted of ephemeral military posts, with the aim of controlling the strategic river mouth and establishing the Ostia saltworks. Only after the fourth century bc the coastal environment was stable enough for the foundation and development of the town of Ostia

Late Holocene palaeoenvironmental evolution of the northern harbour at the Elaiussa Sebaste archaeological site (south-eastern Turkey): evidence from core ELA6

“…The contemporary presence of Chenopodiaceae, foraminiferal linings, and dinoflagellate cysts, as in other Mediterranean coastal pollen records in saline environments (Bellotti et al, 2011;Di Rita and Melis, 2013), supports the micropalaeontological evidence of a brackish/marine aquatic environment.…”

Long‐Term Interactions between the Roman City of Ostia and Its Paleomeander, Tiber Delta, Italy

“…Paleoenvironmental data comes mainly from the littoral (Bellotti et al, 1995(Bellotti et al, , 2007C. Giraudi, 2004;Milli et al, 2013) or the lagoonal systems (Di Rita, Celant, & Magri, 2009;Bellotti et al, 2011;Carlo Giraudi, 2011;Vittori et al, 2015), or else from the harbor basins of Portus and Ostia (C. Giraudi, Tata, & Paroli, 2009;Goiran et al, 2010Goiran et al, , 2014Hadler et al, 2015), but little data available for the Tiber channel during the Holocene.…”

The Canale di Comunicazione Traverso in Portus: the Roman sea harbour under river influence (Tiber delta, Italy)

“…The major migrations of the Tiber channel have been divided into three major phases: (i) During the Late Pleistocene, the palaeo-Tiber flowed into the northern part of the delta (Bellotti et al, 2007); (ii) The second stream way switched to the middle part of the present delta ca. 7000 BP (Bellotti et al, 2007); (iii) During the 9th-8th c. BC, the Tiber mouth moved to the south near Ostia Antica (Giraudi et al, 2009;Bellotti et al, 2011).…”

“…The Canale di Comunicazione Traverso in Portus Pellegrino, 2000), lagoons (Giraudi, 2002;Di Rita et al, 2009;Bellotti et al, 2011) and the coastline variations (Giraudi, 2004;Rendell et al, 2007;Bicket et al, 2009) more precisely. In central Italy, more intense fluvial activity seems to have occurred during Roman Imperial times and reduced during the Late Antiquity and the early Middle Ages (Benvenuti et al, 2006;Bicket et al, 2009).…”

“…Studies focused on the environments that existed prior to the building of the harbour and on ancient harbour basins (Goiran and Morhange, 2003;Marriner et al, 2010). Preharbour aspects have been approached mainly through the study of the migration of the Tiber River in this area of the delta (Segre, 1986, Giraudi et al, 2007Goiran et al, 2007;Giraudi et al, 2009;Bellotti et al, 2011) and through the position of the shoreline during historical times (ArnoldusHuyzendveld, 2005). The harbour itself was studied through the reconstruction of basins' shape, and through detailed sediment analysis (Arnoldus-Huyzendveld, 2005;Giraudi et al, 2007;Goiran et al, 2008;Bellotti et al, 2009;Giraudi et al, 2009;Goiran et al, 2010;Sadori et al, 2010).…”