The Midas monument, an impressive cult facade located in the southern part of the Eskişehir province in central Anatolia, Turkey, was made within tuffs (white and pink), which now have deterioration problems. In this study, the depth and characteristics of the weathering zones that have developed in the white and pink tuffs have been investigated through thin-section studies, X-ray powder diffractometry, methylene blue adsorption tests, major-element analyses, and some index parameters. It has been determined that the feldspar minerals are mechanically fractured due to weathering. The tuffs contain small amounts of clay minerals. An approximately 1-cm-thick silica-rich zone has developed under a lichen cover on the pink tuff. The chemical weathering of the tuffs produces weathered zones, which are 4.5-cm-thick within the white tuff and 2.5-cm-thick within the pink tuff. The index properties of the tuffs are slightly affected within the first 2.5 cm.
TOPAL, TAMER and SÖZMEN, BURAK (2001) "Characteristics of the Weathering Zones Developed Within the Tuffs of the Midas Monument," Turkish Journal of Earth Sciences: Vol. 10: No. 2, Article 3. Available at: https://journals.tubitak.gov.tr/earth/vol10/iss2/3