Physical properties of Tabriz gray marlstone, NW of Iran

چکیده مقاله

Tabriz is one of the largest cities in Iran, with a population of more than2 million. Marlstone is the bedrock of most areas of the city. These marls, consisting of limeand clay, are found in different colors such as yellow, olive, and gray, which mostly belong toBaghmishe and Upper Red Formations. These marls have different amounts of organicmaterials and in high percentages cause the formation of lignite. The physical characteristicsof the marl are different and the gray marl has a high density and strength. Another importantcharacteristic of marls is the high rate of weathering which in excavations, changes over sev-eral months and turns into soil. Therefore, marl is considered both a weak rock and a hardsoil. This study, by sampling and conducting experiments, presents the physical and mechan-ical characteristics of gray marls in different parts of Tabriz city. The carbonate content of thementioned marls is between 30 and 60% and their dry unit weight is between 17.5 and 20.0kN/m3. The clay minerals in these marls also include .illite, montmorillonite, etc