Effects of geologic conditions on rock quarry operations, Istanbul, Turkey

In Istanbul, about 50 rock quarries have been opened for the production of specification quality concrete aggregates. Formations exploited include Catalca granite, Kucukkoy sandstone, and Cebecikoy, Hereke, and Kirklareli limestones. In this study, engineering geology parameters affecting the quality of aggregate production and the operational characteristics of rock quarries in these rock types are investigated. Faults, schists that are intruded cut by granites, and microgranites that formed by segregation at the edges of granite intrusions have a negative effect on aggregate quality and operations at quarries in Catalca granite. Dikes, faults, folding, weathering, and lithologic transitions in Kucukkoy sandstone and Cebecikoy limestone have a significant effect on the quality and operational characteristics of those quarries. In Hereke limestone, differential weathering, dolomitization, karstification, and tectonic contacts create similar problems. Lateral and vertical lithological changes, overburden units, karstic openings, and clay-filled fractures cause geologic problems for operations in the Kirklareli formation. Overall, these lithologic and operational problems account for approximate productive reserve losses in these quarries of 15-30 percent for Catalca granites, 12-70 percent for Kucukkoy sandstone, 5-20 percent for Cebecikoy limestone, 5-30 percent for Hereke limestone, and 5-50 percent for Kirklareli limestone. More carefully planned quarrying of these rock types can substantially reduce these losses for more productive operations and the production of construction aggregates of consistently higher quality.