Abstract
Various kinds of rocks can be used as building stones based on their durability, appearance, and availability. During many periods of times, particularly the Hellenistic, tufa rocks were used as building stones because of their appropriateness for construction. In this research, tufa rocks exposed at Kurkur Oasis are evaluated based on various geological, petrophysical, and geomechanical investigations on 47 rock samples collected from four sites in the study area. Mineralogically, the studied tufa consists essentially of calcite with slight amounts of other minerals such as quartz, dolomite, gypsum, halite, and clay minerals. The tufa rocks are characterized by heterogeneous petrophysical and elastic properties. Porosity, density, and the geomechanical properties vary widely based on different facies and diagenetic processes. Major geomechanical differences between the studied rocks give constraints on the use of these rocks as bedrock foundation, or as construction and building stones. The obtained results and correlations between the different parameters help to predict the geomechanical properties from the more easily measured elastic and petrophysical parameters. Although the uses of tufa as an ornamental stones may be productive to the national economy, however, it is suggested that processing the tufa into polished, ornamental stone, cladding, tiles, and face slabs will be of more economical value both to the investors and the national economy especially at this time of economic stagnation.