BADANIA GEOLOGICZNE MATERIAŁÓW KAMIENNYCH WCZESNOŚREDNIOWIECZNYCH BUDOWLI KRAKOWA

Abstract

GEOLOGICAL INVESTIGATIONS OF STONEWORK OF EARLY MEDIAEVAL BUILDINGS IN KRAKÓWAbstract. Stones used in early mediaeval buildings in Kraków were investigated. Analysis of diversity of stones used in the buildings, their shape and size, with regard to the geology and resources of the Kraków vicinity, allowed evaluating skills of ancient miners, carriers and stonecutters. It helped considerably in reconstructing of a succession of different stones and sites of their quarrying. The following stone types have been recognized: thin-plated compact sandstone (Carpathian flysch; Lower Cretaceous) and limestone (Upper Jurassic); thick-plated compact sandstone (Carpathian flysch; Lower Cretaceous); massive, irregularly breaking limestone (Upper Jurassic); soft, regularly splitable (dimension) Istebna sandstone (Carpathian flysch; Cretaceous/Paleocene). Thin-plated sandstone and limestone were used in the oldest, pre-Romanesque buildings on the Wawel Hill. Thick-plated limestone was applied in the walls of the Romanesque churehe of Wawel's St. Gereon and in the Benedictines Abbey church in Tyniec. Irregular limestone clumps have been commonly used since the very early stages for both constructing of the foundations and filling interior of the walls faced with slabs and plates. Later, as the stonecutters skills developed, regular blocks and bricks were cut from the massive limestone. The soft Istebna sandstone appeared the last in the Romanesque buildings. Its thick-bedded deposits yielded large blocks suitable for cutting columns and tombstones. Analysts revealed that various types of the stones were relatively very homogeneous. On the other hand, stones used in different parts of buildings were considerably variable. The only exception are the walls of the oldest part of the Dominicans convent. The stones used there stemmed probably front various, earlier demolished structures. Volume of the stones used in buildings, estimated from the architectonic reconstructions, points to the size of ancient quarries. The largest elements were probably cut from blocks quarried from rocks (tors) or cliffs developed on natural outcrops and easily mined.,