Off-site embankments to protect fields from the growth of peatlands in the Valli Grandi Veronesi Meridionali (Italy) during Middle and Recent Bronze Age

Abstract

In the background of the late-Holocene landscape of the Southern Valli Grandi Veronesi (VGVM) and nearby Bonifica Padana, an area that stretches between rivers Adige and Po and which is drained by the river Tartaro, was taken into consideration the position of a long embankment that ran through the territories of the two large moated sites of the middle and recent Bronze Age, Fondo Paviani (FP) to east , and Castello del Tartaro (CdT) to west. The location of this particular embankment called SAM (from italian southern embanked road), more than ten km long, and arranged parallel to the Tartaro old riparian belt, since long time attracted scholars as a witness of an old territorial organization, probably related to spatial distribution of cultivated or pasture by the communities who lived in the two large villages, bounded by massive ditch and bank systems. On the basis of recent acquisitions of new DEM and LIDAR sources and aimed field investigations, then merged into geo-chronological and chrono-typological analysis in the laboratory, was developed a research addressed the chrono-stratigraphic, cultural-evolutionary and functional scan of the SAM construct. For this purpose, the archaeological, stratigraphic and chronological record have been reviewed from a series of very significant off-sites, with stratigraphic columns documenting paleo-environmental and archaeological-functional reconstructions. They allowed to established the obvious links between the infrastructure of the ditches of the SAM embankment and the network of secondary rural ditches that seemed to drain and distribute waters in the parceled fields next to the large contemporary sites. In Ponte Moro off-site we captured the chrono-stratigraphic position of SAM embankment through the dating of two peat samples undertaken immediately before and after the stratigraphic position of the embankment. The datings have yielded an earliest date for the construction (MBA-RBA) and a later date of the abandonment of the earthen structure (RBA-FBA). In the Fosso Sarego off-site the stratigraphy documented the composition and the morphology of the embankment and its lateral ditches. These were connected with the neighboring ditches and drains, and especially with the droveway, a road of service for herding that crossed the cultivated area of the CdT near-site, to reach meadows and pastures of wetlands placed within the perifluvial r. Tartaro strechtes. On the sections and on open-area excavations at the Fosso Fazzion off-site were found the remains of anthropic surfaces, connected with the use of pits and silos well placed next to small sites (farms), corresponding to the first evidence of a stable-occupation of land, dating back to the transition between the EBA and MBA. In the Stanghelle off-site were detected morphologies of long pairs of rural ditches filled by manure from the nearby village and dated to a horizon of between EBA and MBA, similarly to Fazzion off-site. Finally at the near-site the so-called hydraulic- node of CdT, an open-area investigated at the intersection of drains protruding from the moat of the SE corral, ceramic fragments in situ dating to RBA were recovered, attesting the connections with irrigation ditches around small enclosed fields. The comparison of these datings, the relative chronology and stratigraphic relationships established between SAM, channels, ditches, and agrarian drains revealed the possibility of achieving a first definition of land organization in two agrarian-settlement phases for the two major CdT and FP sites. The archaeobotanist contribution from a first set of pollen analysis carried out from Ponte Moro samples, allowed to specify the important role of grass-grazing percent in relation of cultivated land and woodland, the latter testified by an higher percent of AP compared to the average of Emilian data. The chronological contribution from finds proposed here, concerned the analysis of a complete sample of ceramic material recovered from a intrasite excavation by F. Zorzi made around the mid of the last century and documented in a dissertation by Zanetti (1970-71). It allowed for the first time to present aspects of material culture (pottery facies), belonging to the first large RBA settlement of CdT, surrounded by the embanked. On these basis was initiated a revision of the stratigraphic position of the two samples for14C dating collected in the 90’s of the last century from the great embankment of CdT, both related to MBA/RBA. In the light of the analysis of the above mentioned ceramics, it was possible to discriminate a phase of MBA3 nucleated site without bounding embankment, but probably with a moat, from the later phase of RBA with massive embankment and surrounded by multiple ditches. Finally, the juxtaposition of the two systems separated from the earthen bank of the SAM, first meadows and pastures, latter fields delimited by long ditches (maybe opened fields) and others small and closed, it has given rise to an important result directed to the definition of socio-political organisation which regulated this fundamental transect in the MBA-RBA for the economy and polity of VGVM near the sites of CDT and FP. The construction of the SAM embankment, erected to preserve the balanced distribution of lands allocated to support the two major sites, could therefore be reviewed as an expression of a huge collective work, continuously maintained, presumably demanded by the elite-polity of VGVM, to prevent the formation of peatlands. These, due to the rise of water table for paleoidrographic reasons, tended to invade the cultivated fields. This engineering earthwork had to play an important role for regulation and control for the drain and irrigation network made of main and secondary ditches extending to the nearby fields, before dissipating in the lower land of marginal pasture-wet meadows, next to fluvial woodland.