Platy limestone – geologic definition and its use as a mineral commodity

The final actions within WP3 were to carry out an evaluation of platy limestone as a mineral commodity and natural heritage. According to the recognized spatial occurrence and potential of the platy limestone types previously defined on the maps, we assessed them to be a mineral commodity with the final goal of identifying potential quarrying areas. Paleontological and sedimentological historical data on platy limestone and new data were also evaluated from the point of view of natural heritage and some geo-sites were proposed.

For the exploitation of limestone plates, the most important factors are the thickness and position of the platy limestone succession in nature. As presented above, each sedimentary succession is composed of sedimentary strata (beds) of various thicknesses (from a centimetre up to a few metres). In most cases, just a certain portion of the succession is characterized by a platy appearance (beds 1-10cm in thickness). This means that platy limestone mostly occurs only in a restricted part of the unit at the surface (outcrops), although some units can be completely characterized by platy limestone (100%). In addition, extraction possibilities depend on the relation of the geological and morphological features.

According to expert geological evaluation, the identified platy limestone types along the entire project area were classified into three categories: 1 – low potential (grey colour on the map), 2 – potential (yellow colour on the map) and 3 – high potential (orange colour on the map). The main criteria for the division were:

• thicknesses of individual platy limestone horizons within the entire geological unit succession (percentage of platy limestone)
• spatial occurrence of platy limestone
• field expert geological evaluation of quality related to general lithological characteristics
• known use of platy limestone as a building material