Karmen Peternelj, Sanja Alaber, Miloš Bavec, Stefano Devoto, Stefano Furlani, Goran Glamuzina, Jernej Jež, Tvrtko Korbar, Maja Oven Stanič, Maria Luisa Perissinotto, Fabiana Pieri, Duška Rokavec, Ivan Stanič, Domen Zupančič
A review of the use of limestone plates as architectural building material revealed that in the southern part of the Kras in Slovenia especially, a particular type of limestone plates were used for roofing. According to geological definitions, this type of limestone is not classified as platy limestone as its platy appearance is not related to its genesis (processes of deposition and diagenesis) but is of tectonic origin. Dense systems of parallel tectonic fissures/fractures enable the excavation of thin, 3 – 10 cm thick, high-quality limestone plates (Fig. 5.5). This type of limestone plates were excavated in the limestone sequences of the Repen and Lipica Formation. The rudist bioclastic limestone plates of Repen Formation were used for roofing in a wide area of the southern Kras. They were excavated in a narrow belt of the Repen Formation where abandoned quarries were also evidenced in the framework of this project. In central Kras area, fractured limestone from the Lipica Formation was also locally used for roofing.
As a possible option for the acquisition of relatively good quality limestone plates, we propose the excavation of fractured Repen limestone in the Repen Formation. This type of limestone is exposed in a wide belt between Divača and Sežana. The most perspective location is the active Griža (Tavčar) quarry near Povir.
It should be noted that this stone occurs in a relatively limited area of the southern Kras. Quarrying limestone plates along fractures, even with modern equipment in an active quarry, could be a complex, time consuming and expensive process and therefore only a limited amount of plates for renovation of roofs can be acquired with this technology.
Four main sets of geological recommendations and guidelines on the acquisition of appropriate limestone plates useful as building material are suggested:
The first option is possible for the land area of Zadar County and selected parts of Herzegovina where legal active quarries exist. The second proposal covers almost the entire studied project area where abandoned quarries of quality platy limestone can be found. The third option is based on the most traditional methods of exploitation and can be suggested for areas without soil, where limited stone-gathering on the surface would not significantly impact the environment. The use of fractured limestone as a fourth option can only be proposed for a limited area of the Slovenia Karst.
