This contribution presents results of a geoarchaeological investigation of the Macchiabate necropolis of Francavilla Marittima (Calabria, South-Italy). Previous studies since the 1960s focused on individual graves of the necropolis (in use between the 9th and 4th century BC). The geoarchaeological investigation consisted of geomorphological, topographical and soil surveys with support of Lidar data, grain-size and geochemical data. This approach offered the possibility to study site formation processes and the relation between the topography and development of the necropolis.
The Macchiabate necropolis lies on a plateau in the foothills of the Pollino massif near the Sibari plain. Topographic measurements within the confines of the Macchiabate archaeological park revealed under the dense vegetation undulating surfaces, ribs, depressions and relatively flat surfaces. The texture and arrangement of surficial deposits were examined as well as the topsoil and subsoil, in particular the degree of soil truncation. A substrate of coarse-grained alluvial deposits (probably of Pliocene-Pleistocene Age) was found in which a reddish loamy soil rich in iron oxides (chromic luvisol) has developed with measured thickness up to 114 cm. The best preserved natural soil was observed under a burial mound while elsewhere more truncated soils were found.
The geomorphological stability of the site, the well-drained soil and natural abundance of stones that could be used to cover graves were advantageous features to construct a burial ground in this spot, besides good visibility, natural barriers and proximity to an Iron Age-Bronze Age hilltop settlement. The hard soil and rock material must have been difficult to dig into during the use as burial ground just like in present times. This is in line with observations that Iron Age and Bronze Age graves are not carved into weathered bedrock but are laid out in anthropogenic deposits above the natural soil or into the upper layer (B-horizon) of the red soil.
The shape of the terrain before the use as burial ground was probably smoother. However, field observations also indicate traces of a relict alluvial fan which take the shape of bar- and swale deposits on the surface and in outcrops by poorly sorted conglomerates. The natural topography could have affected in a number of ways the spatial arrangement of graves.
The relatively gentle slope, the high amount of rock fragments at the surface and the well-drained soil are factors that reduce surface water runoff and soil erosion. Some slope segments are prone to erosion, especially cultivated fields. This is reflected by truncated soils and a relatively thick ploughed topsoil (40-50 cm) which means that graves can easily have been disturbed. Eroded soils (leptosols, cambisols, truncated luvisols) were also observed on the southern and western plateau-edge. Besides natural erosion, it can be linked to modern disturbances such as land levelling and installation of fences.
The lower slopes in the eastern part of the burial ground seem to be subjected to colluviation: augerings near Area Est with traces of Iron Age graves indicate local build-up of 40 to 90 cm thick colluvium which can potentially cover remains of graves.
Potential burial mounds were identified, apparantly smoothed by ploughing, water erosion or intentional levelling. The locations of mound fill borrow areas are more difficult to determine. The data suggests that earth and stones were dug up in various parts of the plateau. On the basis of examined rock types, stones may also have been collected in a nearby narrow stream valley or in the river plain further south.
Modern land disturbances were mapped, although complicated by dense vegetation, such as traces of excavations, piles of stones near arable lands, vertical cuts, paths with compacted soils and signs of erosion. These disturbances can be linked to spatial differences in the preservation potential of archaeological remains.