Expertise through archaeological surveys

Sometimes, during the procedure for evaluating impacts on cultural heritage for any type of installation that will require this procedure; given the detection of archaeological remains on the surface of the land subject to this evaluation, generally dispersed and occupying large areas that condition the proposed project, we recommend carrying out archaeological expert surveys in our reports.

These surveys, which sometimes raise suspicion among customers because of “just in case”, are those that make it possible to determine the presence or not of underground structures “in situ” and thus be able to delimit the origin of these surface remains or to rule out the presence of elements in the subsoil because the original site is completely devastated.

This also avoids, to a large extent, the possible “surprises” of the appearance of structures not detected on the surface with the consequent disorder of work stoppages due to the need to document the remains found.

In these cases, cultural heritage services generally respond to our recommendations and establish as a condition for the approval of the project in question the carrying out of these surveys for a possible effect on the historical heritage.

As we mentioned before, in many cases, the application of this measure in cases of the presence of archaeological remains on the surface makes it possible to delimit to a large extent the extent of the protection area to be established in that reservoir, facilitating the installation of the project in question, whether it is a solar plant, wind farm, the installation of a new power line, the implementation of irrigation in some plots of our farm, the construction of an agricultural warehouse or the opening of a quarry.

Something like this happens in the case shown below, in which, in front of a protective perimeter of 250 m in radius with respect to the central point of the affected site proposed in principle by the corresponding administration, the carrying out of archaeological expert surveys made it possible to reduce that perimeter ostensibly, facilitating the development of the project in question.

This type of archaeological action is carried out by mechanical means, using a backhoe or mixed excavator with a smooth-edged bucket (cleaning) so as not to leave traces of the teeth on the excavated surface, and then manual cleaning of the exposed sections, under the direct supervision of an archaeologist-director and an assistant technician at least, according to the proposed distribution of probes made in each case, normally following the physical conditions of the terrain, so as to allow observation and documentation any possible damage to the archaeological heritage.

Appraisal surveys usually represent around 1% of the area of the plot affected by the earthworks of the project, which are carried out until the wall is crowned, to verify, as we have mentioned, the presence or not of underground elements of heritage interest and their state of conservation if so.

Based on these initial approaches, the methodology applied to record the results obtained in the field work is as follows:

• Stratigraphic record

The proposed archaeological survey is carried out following the principles of natural stratigraphy and the Harris systematization of the information obtained (E.C. Harris, 1979). In this way, we take into account the concept of Stratigraphic Unit as a consequence of natural or anthropogenic action. These units can be classified into strata or anthropically constructed structures. The extraction of land, therefore, although mechanical, is carried out in an orderly manner following the existing strata (vegetation, plant level, landfills, etc.). The mechanical work is complemented by manual cleaning by several archaeologists whenever necessary.

• Graphical record

The graphic record consists of a planimetric representation and a photographic report of the works carried out. With regard to planimetry, elevations are made of some of the representative profiles; and as for the photographic report, the work process developed is documented, as well as the different archaeological units and elements derived from archaeological expertise.

• Descriptive record

The descriptive record of the different stratigraphic units is based on the type files commonly used in archaeological interventions. They collect data relating to the physical characteristics of each unit, their description and the stratigraphic sequence, or physical relationship existing between the different units, from which the chronological sequence can be established.

Summarizing, therefore, given the discovery of archaeological remains scattered on the surface of the prospected terrain, it is of great interest to carry out archaeological surveys that allow us to delimit the structures present in the subsoil or, even, to determine their non-existence, in such a way that we limit the deposits in case underground elements are identified and avoid unscheduled paralysis in the works of the projects related to these actions.

BIBLIOGRAPHY

Harris, Edward C. (1991). Principles of Archaeological Stratigraphy. Barcelona: Editorial Crítica.

José Luis Serna, Archaeology