Petrographic and petrophysical characterisation and structural function of the heritage stones in Fuwairit Archaeological Site (NE Qatar): implications for heritage conservation

Abstract

Several types of limestones have been traditionally used for building mosques, houses and sheds in the Fuwairit archaeological site (NE Qatar). These limestones were characterised, and profiles of semi-collapsed walls examined to estimate the percentage that each building stone occupied and its structural function. Holocene beachrocks were the most used building stones. They were installed mainly as header masonry stones in the walls following coursed random rubble masonry. Pleistocene oolites were used mainly as stretcher masonry stones and Umm Bab Member of Dammam Formation (middle Eocene) as wedges and filling stones of the inner cores between the masonry wall faces. These last building stones were collected in the rocky desert, whose surface is covered by stone fragments resulting from thermal dilatation. Therefore, thermal expansion measurements were performed to investigate the breakage of the Umm Bab Member. Umm Bab Member has the lowest effective porosity and water absorption, and the highest bulk density and ultrasonic pulse velocity. This stone presents the best quality. Oolites have an intermediate quality and beachrocks have the worst quality as building stone. Historic quarries of oolites were found with abandoned stone blocks in Jebel Fuwairit fossil dunes.