PROWENIENCJA SUROWCA RZEŹB I KOLUMN ZE STRZELNA Z KOLEKCJI MUZEUM NARODOWEGO W POZNANIU W ŚWIETLE BADAŃ PETROGRAFICZNYCH

The research note discusses the outcome of petrographic studies relating to five Romanesque stone monuments from Strzelno, featured at the National Museum in Poznan. The research encompassed: - a perpendicular fragment of a column shaft 50 x 24 cm (dep. 64), originating from the post-Premonstratensian church of the Holy Trinity in Strzelno, covered with an ornamental tendril; - a fragment of the shaft of a column with an angel 28 x 28 x 28 cm (dep. 564) from the church of the Holy Trinity; - the head of Christ from the foundation tympanum in the rotunda of St. Prokop, damaged in a fire from 1945 (P. 19); - the head of a statue 22 x 20 x 21 cm (dep. 563), unearthed in the course of archaeological excavations in front of the rotunda of St. Prokop in 1950; - a column capital 40 x 36 x 20 cm (dep. 65) from the church of the Holy Trinity, with acanthus leafs in the corners and a fragment of a lamb. The examined monuments disclosed the presence of two types of sandstone: white quartzose sandstone, used for making the shaft of the column covered with an ornamental tendril, the shaft of a column with an angle, and the head of Christ, as well as subarkose sandstone used for the head of the statue and the column with acanthus leafs. It is difficult to propose an unambiguous origin of the white sandstone which could have been mined in the Warta river valley, e. g. near Konin-Brzezno (Tertiary sandstone), or in the Sudety Mts. in the regions of Zlotoryja, Lwowek Slaski, and Boleslawiec, as well as in Klodzko - between Polanica, Radkow and Krzeszowice (Cretaceous sandstone). The mineral composition of the red sandstones, their colour, and the presence of a calcite-clayey cement indicate a resemblance to the Permian period (Rotliegend) or Triassic sandstone (Buntsandstein) which do not occur in the Polish lowlands, and whose nearest outcroppings are located in the Sudety Mts. Particular attention is drawn to the petrographic similarity of this raw material to the sandstone in the portal of the abbey in Olbin, inserted into the southern nave of the church of St. Mary Magdalene in Wroclaw. The establishment of a connection between those monuments was rendered possible by a petrographic expert study of the abbey portal sandstone conducted by Alfred Majerowicz in 1963. The description contained therein corresponds to the petrography of the red sandstones from Strzelno. This similarity cannot be regarded as accidental since the raw material in question is not universally available. A sculptor could have used a similarly coloured raw material but he was unable to perceive the forms of the microscopic kaolinite crystals and the carbonates between the quartz grains. Consequently, we may conclude that the sandstone was brought over to Strzelno (in a raw form or as a completed work) probably by the same stone-cutters who made the portal for Olbin Abbey.