Archaeology, like any science, has its own methodology which is adapted according to the objectives and circumstances of each case being studied. In this respect, the work undertaken on the structures of the present building serve as an example to explain the scientific method applied in Puig Ciutat.
The present state of the excavations does not yet allow an answer to many of the questions hinging on the site. Nevertheless, geophysical surveying has made it possible to focus the excavation in those areas where the presence of built structures has been recorded. Thanks to this strategy, in a short time we have been able to obtain the largest possible quantity of data for drawing up the first interpretative hypotheses.
What do we know?
Geophysical surveying has identified the presence of a building in the middle of the agricultural area. Some of the techniques used, such as ground-penetrating radar, have made it possible to define the geometry of the structure and establish its depth about 0.5 metres (20 inches) beneath the surface.
What do we see?
A building measuring 11 x 11 metres with an entrance in the form of a passageway which very probably opened onto a distribution space inside. Two rooms have also been made out abutting the main façade and, finally, a space subdivided into four compartments at the back. The two innermost rooms are of a smaller size.
In the course of the excavation, a large amount of carbon and shattered ceramics have been documented that suggest the building may have been destroyed.
What do we deduce?
The building is an unusual construction that stands out in the settlement. Its size suggests it could be the residence of the commander or person in charge of the establishment praetorium) or a building with an important administrative function in the same context (principium).
Although at present the data do not offer any more information about its purpose or its destruction, we hope to obtain more results in future work.
Aquest sondeig es va realitzar amb l’objectiu de confirmar la presència i les característiques d’un edifici de grans dimensions, que havia estat prèviament detectat per les prospeccions geofísiques.
The archaeological excavation revealed a square building, 11 by 11 metres, divided up into various rooms opening onto a central distribution space. This was reached by a passage that communicated with the building’s only entrance, open in the southern façade. The date provided by the ceramic material recovered confirmed that the building belonged to the latest phase of occupation of the settlement, in the Late Roman Republican Period.
The work revealed that the structure had been heavily affected by farming work in the field in recent times and some of the walls that divided up the complex have not survived. Despite the poor condition of the remains, carbon was found which could have been part of the door latch.
Two surveys performed in the interior of the building showed that it had been looted in ancient times, probably to recover some of the stones from the north and west walls.
Its large size make this building an important one in the settlement’s complex of buildings. According to documentary sources, a building of these characteristics could have been the praetorium, or residence of the Roman camp’s Commander, or the principia, or administrative building. In the case of Puig Ciutat, this building could have fulfilled both functions.
[left] Drawing of the structures located superimposed on the ground-penetrating radar data. [right] Interpretation of the located structures superimposed on a photograph taken from a drone.
July 2010-December 2015
Excavation work in the building
Excavation work in the western rooms of Building 1
View of the entrance and the passage leading into the building from the south. In the foreground can be seen the carbon which could have been part of the door latch
South-west section of the central building after the tops of the walls have been marked out
Two views of the test trench dug at the south-west corner of the building. The original wall can be seen damaged below the layer of small stones with which the robber trench was filled in
Geophysical methods have made it possible to explore the site in detail and more exactly define the geometry of the structures and their geological surroundings. In this context, geophysical surveying has centred on two fields in the western section and, especially, on the field in the eastern sector, as they allow extensive work that is impossible in the wooded areas.
The main techniques used are magnetic surveying, which provides information on areas with alterations in the electromagnetic field like the ones produced by combustion, ground-penetrating radar, which provides a more precise description of built structures, and electrical surveying, which documents variations in the potentials of sediments.
The results and interpretations obtained with the different techniques are used in the planning and management of subsequent excavations.
Image: © Orthophotograph property of the Institut Cartogràfic i Geològic de Catalunya, accessible on www.icgc.cat.
Map of the magnetic gradient of sections 1 (west) and 2 (east)
The blue and red colouring indicates areas with temperature alterations or containing metals. The black linear elements could indicate built structures. The white elements could indicate accumulations of sediments or structures dug into the ground, like silos.
Map of reflected energy
Represented are depths included between 0.55 and 0.65 metres below ground. The built structures and the surface bedrock are in black.
Map of electrical conductivity
Obtained from electromagnetic surveying by the ORBIT group at Ghent University (Belgium). In black, the elements of marl and limestone: rock base and building material of the site. In white, clay marls from higher levels.