Proyecto Arqueologico Sechín Bajo Casma, Peru

Proyecto Arqueologico Sechín Bajo Casma, Peru

Development of restoration and consolidation methods for the loam walls and relief friezes made of clay 3600 years ago

The Casma Valley is a valley of ritual buildings: There is no other valley in Peru where such a large number of such enormous groups of buildings stand this close together – the oldest among them were erected about 5600 years ago. They mark the transition from rather non-stratified agrarian societies to the emergence of central rulership and monumental buildings – first along the coast, and then in the highlands. One of these massive monuments is found at the discovery site in Sechín Bajo whose examination is supposed to provide a new understanding of these structures.

Grabungshügel im Tal von CasmaEarly preliminary works at the Sechín Bajo discovery site took place in 1992. A first archeological examination and topographic survey were carried out in 2000 and co-financed by Archäo Kontrakt Berlin. Since 2003, the research project has been sponsored by the Deutsche Forschungsgemeinschaft (DFG – German Research Foundation) under the direction of Dr. Peter Fuchs. The goals of the project are to investigate the conditions favoring the emergence of the monumental building complex in the Casma Valley, to clarify the facility’s function and define construction stages as well as the site’s exact measuring and its dating.

Development of restoration and consolidation methods for the loam walls and relief friezes made of clay 3600 years ago at the excavation site in Sechín Bajo, Peru. The complicated conservation and protection were carried out in parallel with the archeological dig. This enabled the uncovering of a continuous group of figures of the relief frieze.

The Sechín Bajo discovery site is located at the nothern edge of the Rio Casma Valley, directly where the agriculturally utilized meadow of the valley’s river merges into the desert. It covers an area of approximately 30 hectares with buildings of different ages, surrounded by a long wall towards the desert. The parts examined were the main structure as well as a system of platforms with a floor plan of about 125 m by 185 m and a preserved cave of ca. 12 m. Geophysical measurements were able to proof the existence of an older, predecessor construction which nevertheless had been partly built-over by the later structures.

In addition to other important finds, a prehistoric relief frieze made of clay mortar was discovered on a temple wall. It is located in the first and largest courtyard of the temple’s complex. Laterally, the frieze was surrounded by walls with a height of about 5 m which had been carefully plastered with clay. The large-sized reliefs were worked into this plaster. Based on insights gained so far, the frieze is estimated to be about 3600 to 3800 years old. The motifs depicted are persons characterized by various mythological, or resp., religious, attributes, insignia and weapons.

Grabungsfeld der "runden vertieften Plätze"Upon the discovery of the frieze, it became clear that the relief’s layer was seriously in danger due to static faults in the quarry stone masonry which would have prevented any further exploration. The areas of the relief had already been heavily damaged by the collapse of the upper walls in the course of a prehistoric earthquake yet were nevertheless supported by debris that had tumbled in front of the walls. Here and there, individual parts of the relief which had fallen down were found in the debris and could now be recovered, too. It was pressing that excavations be accompanied by preservation and protection.

Based on the examinations of 2003, new methods and techniques were now developed and applied so that the clay frieze could be stabilized and secured. The complicated protective conservation and protection were carried out in parallel with the archeological dig. This enabled the uncovering of a continuous group of figures of the relief frieze.

To protect the fragile frieze, the area treated was supported by a retaining wall after the campaign’s completion and backfilled with sand. All steps were carried out under the premise to enable, at any time, future measures independently from knowledge of this restorative protection that had been carried out, and to preserve the frieze in its original state.

Client:

Freie Universität Berlin unter der Leitung des deutschen Archäologen Dr. Peter Fuchs

Project period:

2003 – 20013

Participant:

• Dr. Peter Fuchs, excavation and project manager, Lateinamerika-Institut der Freien Universität Berlin

• Dipl.-Rest. Jörg Breitenfeldt M.A., RAO Berlin

• Renate Patzschke (M.A.), Archäo Kontrakt

• Prof. Dr. Jürgen Golte, Lateinamerika-Institut der Freien Universität Berlin

• Dipl.-Geologe Bernhard Lorenz, Büro für Geophysik Lorenz, Berlin

• Deutsche Forschungsgemeinschaft (DFG)

• Lateinamerika-Institut der Freien Universität Berlin