Early Piast dynasty (10–11th century) stone architecture in western Poland in a geological context

There is no consistency in reporting the stone material used to construct the first structures in the early Piast dominion (10–11th century) in Poland. The role and importance of the type of the stone building material used at that time has been underappreciated if not completely ignored. It has been stated that glacial erratics comprise the fundamental rock material used in the early Middle Ages for building, representing up to 98% of construction material. The remaining rocks used in building construction included local calcareous sinter, bog iron ores, Jurassic limestone from the Piechciny-Barcin region and gypsum from a salt dome in the village of Wapno in western Poland, while Miocene sandstone excavated at the inception of the Polish state in the Brzeźno Quarry near Konin has received significant attention. There appear to have been distinct phases of use of the various types of rock material. There was likely a link between the development of tillage and the development of monumental stone architecture from the Middle Ages. Deforestation resulting from the development of agriculture helped expose the glacial erratics used in the stone architecture of the first Piast rulers.