Structural, petrographic and mineralogical characteristics and diagenetic aspects of Kandira stone from Northwestern Turkey

Abstract

Kandira stone is a unique Late Cretaceous (Campanian-Maastrichtian) carbonate rock quarried by small enterprises in Northwestern Turkey. The rock has been used as a construction material in a variety of applications such as cladding and paving, flooring and stairs, roofing and fireplaces. Recently, the demand for this stone in the production of intricately sculpted shapes has raised questions about its workability and durability. Such questions require detailed characterization of structural, petrographic and mineralogical properties of the stone. This paper provides a database on the earlier mentioned properties collected from Kandira stone sampled from quarries. The investigation comprised field measurement and sampling of the Kandira stone, microscopic examination of thin sections, XRD, XRF and SEM studies. The Kandira stone is biomicritic limestone composed mainly of microcrystalline calcite crystals (micrite matrix), pelagic fossils, shell fragments and sponge spicules. Calcite is the sole carbonate mineral and is accompanied by minor quartz and authigenic clay minerals. Diagenetic alteration involved micritization, limited cementation and neomorphism. These processes were variably active in the marine phreatic and limited meteoric phreatic environment. The compact and closed form textural composition results in a stronger, durable stone suitable for masonry and decorative purposes. Key words: Kandira stone, natural stone, petrographic and mineralogical characteristics, biomicritic limestone, pelagic fossils, diagenesis, Late Cretaceous.