The site of Aquileia (northeastern Italy): example of fluvial geoarchaeology in a Mediterranean deltaic plain / Le site d'Aquilée (Italie nord-orientale) : exemple de géoarchéologie fluviale dans une plaine deltaïque méditerranéenne

Abstract

Résumé Les données archéologiques et historiques montrent que le site d'Aquilée fut l'un des plus importants ports fluviaux de l'Empire romain. Les recherches multidisciplinaires récentes insistent sur l'importance des voies fluviales dans la plaine deltaïque d'Aquilée au cours de l'Antiquité. Les résultats apportés par les paléoenvironnementalistes attestent la présence de paléochenaux fluviatiles de haute énergie, au moins au nord et à l'est du site. Initialement (ix'-vw s. av. J.-C), le tracé des paléochenaux a suivi une direction de composante principalement N-S, avant d'adopter une direction NE-SW. Les facteurs à l'origine de cette évolution hydrographique sont d'ordre naturel et/ou anthropique. L'interaction entre la paléohydrographie du site, la paléohydrologie des cours d'eau et l'aménagement de la ville romaine est clairement démontrée. Les stratégies de développement urbain évoluent en fonction de la dynamique fluviale. En même temps qu'elle s'adapte aux contraintes hydrologiques "naturelles" de la plaine deltaïque, la société romaine contrôle l'extension des environnements hydromorphes ainsi que la géométrie et l'hydraulicité des cours d'eau afin de maintenir de bonnes conditions de navigabilité.

Early exploitation of Neapolitan pozzolan (pulvis puteolana) in the Roman theatre of Aquileia, Northern Italy

“…The use of the volcanic pozzolan exclusively in the preparations of pavements was probably intended to ensure a waterproofed sealing, keeping the floors dry and sound against water infiltrations. Indeed, the theatre was built in the low-lying Aquileia's deltaic plain, affected by recurrent salt wedge 45,46 . Moreover, it was close to "Canale Anfora", an artificial Roman-time channel connected to the Marano lagoon, and a land-reclamation system described by Vitruvius in lagoon-like environments of the ancient Cisalpina, including Ravenna and Altinum (De Architectura, 1.4.11) 99 .…”

“…The structure was built in a low-lying land possibly affected by water infiltrations, an issue involving the whole Aquileia's floodplain in antiquity 45,46 . Such factor required an adequate consolidation of its foundations.…”

The Dunes of Belvedere–San Marco of Aquileia: Integrating High-Resolution Digital Terrain Models and Multispectral Images with Ground-Penetrating Radar Survey to Map the Largest System of Continental Dunes of Northern Italy

“…This phase led to the formation of the coastal plain of Isonzo River, which consists of a coastal wedge of lagoon and alluvial deposits whose maximum thickness is about 10 m near Grado and tends to become thinner landwards [33,35]. Thus, south of the Aquileia-Monfalcone latitude, the surface of the LGM alluvial plain has been largely buried by the Late Holocene sedimentation, and the related channel belts of Isonzo River and Torre Torrent are characterized by wide fluvial ridges elevating 1 to 3 m over the surroundings [23,25]. Presently, Torre is a tributary of the Isonzo River, but in the past this stream reached the lagoon directly, as witnessed by traces of its paleochannels documented west of Aquileia [23,37].…”

“…They have been studied since the 19th century, and several contrasting ideas were put forward about their origin and age, mainly spanning from the hypothesis of Holocene or Pleistocene coastal dunes [19][20][21] to the ones proposed by the geologist Ruggero Marocco. He discussed their possible relations with the remnants of Pleistocene fluvial ridges [22], with the occurrence of a tectonic terrace in the area [23], and, for the first time, he proposed the possibility that they were continental dunes, whose evolution might have been related to the reworking of ancient fluvial channel deposits [24,25]. The dunes of Belvedere-San Marco were recently reported in the map of the geological units of the plain of the Friuli-Venezia Giulia Region at the 1:250,000 scale [3] as continental dunes formed during the Last Glacial Maximum (LGM).…”

Late-Quaternary Evolution of the Semi-Confined Alluvial Megafan of Isonzo River (Northern Adriatic): Where the Fluvial System of the Southern Alps Meets the Karst

“…Radiocarbon dates indicate that the Isonzo megafan was aggrading until 22-20 ka cal BP, while a recorded period of stasis during the Late Glacial and early Holocene occurred in response to reduced sediment discharge [11,25]. Such starvation took place as a consequence of the accumulation of mass-movement deposits in the upper valley [25], which hampered the downstream routing of sediments and led the Isonzo to entrench its course in the distal plain, as documented near Aquileia [26]. Afterwards, the northernmost portion of the Adriatic basin was submerged by the post-LGM transgression around 9.5-9.0 ka cal BP, and the distal sector of the Isonzo megafan started to be partly onlapped by coastal and lagoon deposits, as documented by the age of the Holocene basal lagoonal deposits recorded in the gulf at a depth between −30 and −25 m mean sea level (MSL) [15,27].…”