Stylolite networks in dolomitized limestones and their control on polished decorative stones:a case study from Upper Cretaceous Khur quarries, central Iran

Stylolite networks and their insoluble residues (IR) are among the major concerns and the fundamental controls on the mining and processing of sedimentary decorative stones, largely made from dolomitized limestones. They are mainly used, as natural rock blocks and polished slabs, to construct and decorate floors and walls of buildings and monuments. Representative quarries in Khur areas, east of Esfahan Province, central Iran, are selected for this study in order to evaluate the type and geometry of the stylolite networks in differentially dolomitized limestones and their control on the quality of the mined rock blocks and processed polished rock slabs. Field observation, examining the mined wall-rock cuttings in quarries, and petrography of the selected thin sections of Upper Cretaceous Haftoman Formation were performed with a comparative study of thickly developed, rudist-bearing rudstones-grainstones to bioclastic packstone-wackestone microfacies. What is typically considered in this study is evaluating the geometry of stylolite networks (cells), as they merge and result in a 3D network, rather than laterally continuous single stylolites. This study highlights the primary lithofacies types and diagenesis controls on the mining and processing of sedimentary decorative stones and documents that under relatively ideal tectonic conditions, slightly dolomitized, thick-bedded, relatively clay-free ( < 10% IR), mud-dominated packstones-wackestones provide the best shallow marine, carbonate lithofacies for preparing polished rock slabs. This is in contrast to clay-rich argillaceous limestones with dissolution seams or stylolite networks and pervasively dolomitized, grain-rich platform carbonate lithofacies characteristically with stylonodular, brecciated and chalky textures.