CHARAKTERYSTYKA PIASKOWCÓW LGOCKICH POZIOMU DOLNEGO JAKO MATERIAŁU BUDOWLANEGO ZASTOSOWANEGO W KAMIENNYCH OBIEKTACH DROGI KRZYŻOWEJ W KALWARII ZEBRZYDOWSKIEJ

Abstract

CHARACTERISTIC OF THE LOWER LGOTA SANDSTONES AS A BUILDING MATERIAL USED IN STONE STRUCTURES OF THE WAY OF THE CROSS IN KALWARIA ZEBRZYDOWSKAAbstract. The paper briefly presents the characteristics of the Lower Lgota sandstones as a building material used in chapel buildings of the Way of the Cross in Kalwaria Zebrzydowska. Macro- and microscopic examinations of rock samples show that the Maria Magdalena quarry situated on the slopes of the Żarek Hill was the main source of the building material. Two structural varieties of the Lower Lgota sandstone used in the Kalwaria sacral buildings can be distinguished. The first variety, structureless and usually of medium-grained texture, is light-beige. The other one is dark-beige, structureless with medium- and coarse-grained texture, often disturbed by rusty streaks. Lamination is sometimes observed in this rock type. Due to a considerable thickness of sandstone layers, which can reach 1.8 m, the sandstones were used as a building material. The layers, as a rule, have no fractures and, therefore, could be quarried as large stone blocks. Physical and mechanical properties of these sandstones result from the mineral composition of the grain framework, the amount and type of cement (mainly clayey) as well as from the rock texture and structure. These properties imply, in particular, water absorbability whose mean value is 7.5%. These properties have main negative influence on stone preservation. Despite these limitations, the Lower Lgota sandstones represent a very attractive construction material. It could be an alternative to other Carpathian sandstones, particularly to the Istebna sandstones, commonly used for building purposes. The Maria Magdalena quarry, however, is situated inside the UNESCO World Heritage Site of Kalwaria Zebrzydowska. This position precludes any potential large-scale exploitation of the Lower Lgota sandstones.