Pivko D., 2018: Extraction methods in historical quarries in Slovakia and nearby areas for dressed stone products. Acta Geologica Slovaca, 10, 2, 105–131.

Extraction methods in historical quarries in Slovakia and nearby areas for dressed stone products

Daniel Pivko

¹Department of Geology and Palaeontology, Faculty of Natural Sciences, Comenius University, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia; daniel.pivko@uniba.sk

Abstract

Over 150 historical quarries with its extraction time span were identified in Slovakia and nearby areas on basis of dressed stone products, petrography, historical quarry database, historical and geological maps, aerial photos, and local names. Almost all known extraction methods were identified in the quarries according to tool marks. Most of the stone blocks were extracted in open quarries from rock walls. Some valuable stones were extracted in chambers. Roman ruins were also the source of quality stone in medieval. Some blocks like boulders were obtained from regolith, rock avalanches or volcanic breccia. The most used extraction method was wedging joints because of significant brittle deformation of Slovak rocks. The method was dominant in bedded flysch sandstones. The blocks from massive soft rocks were extracted by the carving with pick or chisel and hammer. The explosives used in the quarries accelerated and facilitated work but fissured a rock. Gunpowder in quarries was used especially in mining regions from the 17^th century which left behind hemi-spherical explosion holes. High explosives, which explosions caused radiating joints, were used since 1870. The drilling a set of vertical parallel boreholes has become the proven method since the late 19^th century. The wedges, splitters or expansive cement were placed into each borehole to split off the block. A more modern way of block extraction is the cutting a soft stone by a wire, chain or circular saw. The methods have been used since the 1930s in marble, travertine, and tuff quarries. In the Middle Ages, the smaller blocks up to 1 m were extracted in the stepped walls without a significant quarry organization. In the 17^th century, the blocks over 2 m appeared for portals and columns. The evolution from the stepped carved quarry walls to more effective straight walls took place in the 17^th century. Some quarries were active only in medieval up to the 16^th century. Many of them were worked-out, other ones were abandoned due to the competition or increased demands on quality.

Key words: historical quarry, quarrying methods, tool marks, dressed stone, Slovakia

Manuscript received: 2018-04-26

Revised version accepted: 2018-10-10