Abstract
The Angkor monuments are the World Cultural Heritages constructed in the 9th century to the 13th century. Sandstone, laterite and brick are the main stone materials used in the monuments. In this study, the sandstones used in the 28 main monuments were investigated and compared to each other. The sandstones can be divided into three types : (1) grey to yellowish brown sandstones, (2) red sandstone and (3) greenish greywacke. The grey to yellowish brown sandstone is most popular and used in almost all monuments. Based on the magnetic susceptibility of the grey to yellowish brown sandstone, the investigated monuments can be divided into 8 groups except for Banteay Srei. This may suggest that the quarry of the sandstones changed with the times. For the grey to yellowish brown sandstones, there is however no significant difference in regard to the constitutent mineral, bulk chemical composition and chemical compositions of plagioclase and garnet. The percentage of the sandstone blocks with the vertical bedding plane decreased abruptly after West Mebon construction. This fact means that the monuments have began to be constructed with taking account the orientation of the bedding plane of the sandstone after West Mebon construction.
