The Archeological and Technical Studies on Unique Architectural Ornaments with Clay Reliefs in Jiroft, Iran

The fifth season of archeological excavation of Konar Sandal Mound Hill in Jiroft (located in southeast of Iran) in 2006 was characterized by discovery of a clay monument on the wall of one of the architectural spaces there. With dimensions of 110 × 95 cm and 18cm thickness, the monument is regarded as the unique and oldest clay relief ever discovered (third millennium BC). On the one hand, historical and artistic values of the unique monument and its location in the site and environmental and human threats causing serious damages to it on the other hand, has made its documentation ever more necessary. The study of constituting materials and building techniques of the monument was done through macroscopic (field and visual study) and microscopic (optical and electron) methods as well as chemical analysis of elements and compounds on the clay foundation and its color layers (FT-IR, XRF, XRD, and SEM-EDS). The results suggest that the clay monument was built in two parts, namely the built-on torso and lower torso (skirt) which was carved out on a cob wall. Then, a delicate finish layer made of clay was put on the colored layer. The finish layer was made by using mineral pigments such as limonite (yellow) for covering the body (i.e. arms, chest and waist scarf), and Ochre hematite (red) and carbon (black) for ornament of embossed skirt. The used clay soil is of montmorillonite type which reacts, expands and contracts significantly due to humidity variation.