From ancient construction, through survival, towards modern conservation: characterization of fine-grained building material at Niğde-Kinik Höyük (Cappadocia, Turkey)

Abstract

In this paper, we studied building materials from the Niğde-Kınık Höyük archaeological site (Southern Cappadocia, Turkey) with the support of historical, architectural, and geological research. The samples were collected within the framework of the Kınık Höyük Archaeological Project, which began excavations at the site in 2011 in a bid to conserve the ancient buildings that would be discovered there. The objective was to characterize the fine-grained building materials as a means of understanding the structural stability they offered, in order to explain how the remains had managed to survive for such a long time. Samples were taken from the coating on different walls, from mud bricks and rendering, and from soil-beaten floors from the different buildings in the settlement. Samples were first observed using a video microscope and then studied by means X-ray diffraction and optical and scanning electron and transmission microscopies. The materials studied were composed of volcanic sands coming from the materials that outcrop in the area. In general, the samples were porous and fissured and minerals of volcanic origin were identified such as quartz, plagioclases, cristobalite, pyroxenes, micas, amphiboles, and olivine together with others of sedimentary origin, such as calcite, and small amounts of clays. The possible presence of hydrated calcium silicates was closely investigated due to their important role in the preservation of ancient building materials, but although we searched for them with a range of different techniques, none was found. This indicates that the longterm conservation of the Niğde-Kınık Höyük archaeological site may be due to the fact that it was buried at constant temperature and humidity conditions and so protected from the weather conditions, which are milder in this area than in any other region of Central Anatolia.