Authors
1
Department of Geology, Faculty of Science, Ferdowsi University Of Mashhad (FUM).Mashhad- Iran
2
Department of Geology, Faculty of Science, Ferdowsi University Of Mashhad, Mashhad, Iran.
3
Department of Geology, Faculty of Science, Ferdowsi University Of Mashhad, Iran.
4
Department Geology Facuity of Science, Bu-ali sina university, Hamedan, Iran
Abstract
Karstification develops in limestones easily due to high solubility. The abundance of limestone has caused them to face this type of rock in different engineering projects. The Ilam Formation is exposed in the Zagros mountains and this Formation contains 195 meters of cream-colored limestone in the type section. Due to the extent of this formation, many projects have been executed on this formation, and they also encounter this formation in oil drilling. Its lower and upper Boundaries are continuous with Surgah Formation and Gurpi Formations, respectively. In this research, lithological studies and determining the physical and mechanical properties of limestone samples of Ilam formation in type section, the solubility and karst development have been investigated. In order to evaluate the solubility of the Ilam Formation, samples were taken from different horizons of the formation and transferred to the geological engineering laboratory for the dissolution test, the samples were evaluated for their chemical composition, engineering properties, and solubility after preparation. The results of XRD show that the oxides include silica, calcium carbonate, clay minerals, and a few numbers of dolomite. The results of the XRF samples show that the major constituent oxides are CaO, SiO2, Al2O3, Fe2O3 and MgO. Additionally, based on calcium and XRF tests, horizons E and F contain the highest levels of calcium carbonate and demonstrate variations in solubility across different layers of the formation. Horizon F, in particular, has the highest rate of dissolution. There are karst phenomena such as dissolution sinkholes, Karen, dissolution holes, canyons, caves, James, gorges, and rain hole Karen in the study area.
Keywords
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