Inter-scientific Dialogue – Multidisciplinary analysis of the navigability and anchorage conditions during the Roman period (Esposende)
The main goal of this project is to know the navigability and anchorage conditions during the Roman period between the rivers Ave and Neiva (including the Cávado) for the supply of the coastal areas of this vast region of the conventus bracaraugustanus and its provincial capital, Bracara Augusta. The complexity of this thematic requires a multidisciplinary analysis, crossing data from geosciences (geomorphology, sedimentology, stratigraphy, chemistry) and natural sciences (paleoecology) with testimonies from social sciences (archaeology, historical cartography, and literary and epigraphic sources).
Regarding geomorphological, stratigraphic, and sedimentological indicators, we intend to analyse the paleoenvironmental conditions of the coastal zone among those estuaries during the Roman period. Previous studies suggest that the Cávado and Ave rivers’ estuaries were wider and more concaved than today (Granja e Morais, 2010) and that wetlands occupied depressed areas along the coast (Granja 1990, 1997, 2002).
These changes in the landscape coincide with significant climate changes, which had repercussions on the relative sea level position, noticeable in some lagoon deposits documented in the coastal zone north of the Cávado estuary, in which Roman era testimonies were found. A concentration of these remains was located on a beach north of Esposende, corresponding to a probable Roman port. A large number of amphorae fragments (in particular Haltern 70) and also cetias were found, probably related to the existence of a roman villa. The importance of these archaeological findings seems to agree with the literary and epigraphic sources alluding to the roman city of Bracara Augusta, which refer the existence of a sea gulf and are unequivocal as to the commercial importance of this city.
The Cávado river would have its mouth to the south of the current one, in Fão, where geomorphological and sedimentological data seem to indicate the existence of a canal. In this context we find relevance in the modern era cartography data (in particular the letter of João Teixeira I of 1648), representing the mouth of the Cávado river in Fão and the Ave’s, wider and gulf-shaped, very different from its current configuration.
The questions raised in the above points corroborate the data obtained in relation to the weather and oceanographic conditions that suggest different navigability conditions for the roman period, more appropriate than the existing.
This project aims to answer those questions, which implies an integrated and extended paleo-environmental reconstitution, based on geomorphological, sedimentological-stratigraphic, paleoecological and radiochronological analysis, which will allow us to infer information on climate, the sea level, hydrodynamics and sedimentary supply during the roman period.