Abstract

The Sitting Buddha Carved on Rockcliff (National treasure No. 201) in Bukjiri consists of porphyritic biotite granite, which was fractured by three joint sets of NE-SW, EW and NS directions. They produced a physical weathering that broke many parts of the Buddha and background. The chemical index of alteration is 59 to 61 from the major elements in the granite that was weathered into producing kaolin minerals from alteration of feldspars and biotite. With weathering degree, major element compositions increase in SiO₂ and MnO, whereas decrease in TiO₂, Fe₂O₃^t, MgO, CaO and K₂O. Change proporations of trace elements to Al₂O₃ increase in all transition elements, Rb and Y, whereas decrease in Li, Sr and Ba. REE pattern increases only in HREE. Particularly, a decrease in CaO, K₂O, Sr and Ba results in what they are effluxed to dissolve from feldspars by groundwater. The Buddha image has been deteriorated into joints, color changes, brown rusts, granular decay, microorganic smears by the such weathering causes as deformation, moisture, temperature variation and microorganic living. The moisture, which leaks along the joints in the granite, not only dissolve to decompose minerals but also grows many microorganism and is frozen over during winter. NE-SW and NS joint sets affect to seep in water during rainy days to
deteriorate the image because they extend outward.

Keywords joint set, physical weathering, chemical weathering, deterioration cause