Comparison of different geophysical techniques in relation to archaeological data for settlement pattern reconstruction – the case study of Nauportus, Slovenia.

Branko MUŠIC¹ / Jana HORVAT² / Franc DIMC³

(¹University of Ljubljana, Faculty of Arts, Department of Archaeology / ²Slovenian Academy of Sciences and Arts, Scientific research centre, Institute of Archaeology / ³University of Ljubljana, Faculty of Maritime Studies and Transportation)

Nauportus functioned as a freight and reloading station during the second half of the 1st century BC and at the beginning of the 1st century AD. The settlement attained the status of vicus (village) in the territory of the Roman colony Aquileia. Dolge njive, the eastern part of the settlement, was erected upon the inner area of the Ljubljanica river bend.
Small trenches were excavated in 1884. Walter Schmid carried out large campaigns in 1934 and 1936, which revealed the ground plan of a fortified settlement.
The aim of applying geophysical survey methods was to ascertain the reliability of some archaeological plan views based on documentation of two excavations conducted by Schmid. Schmid’s documentation was completely revised much later and published together with descriptions of several architectural elements discovered by other archaeological pioneers at this Roman settlement. In addition to the uncertainty over the accuracy of architectural drawings, without some additional investigation, precise spatial positioning of plan views was impossible. Therefore, geophysical survery was chosen as the crucial part of the initiative, to enable more detailed settlement reconstruction and accurate spatial positioning.
Information needed for effective geophysical research design, was obtained from revised archaeological documentation and completed by additional information extracted from Ground Probing Radar profiles carried out in the initial phase of geophysical survey by several randomly directed profiles, georeferenced by applying inexpensive, single frequency GPS system.
On the basis of qualitative and quantitative analyses of geophysical data sets (magnetometry, resistivity, conductivity and GPR), beside the complementarity of techniques applied, it was possible to construct a 3D presentation of preserved architectural remains. Together with existing archaeological data from previous excavations, detailed settlement pattern reconstruction of geophysically explored parts of Nauportus was possible.

Keywords: geophysical survey, multi-method approach, settlement pattern reconstruction