Petrography of glacial tills in the szczerców out crop, central poland – problems of stratigraphic interpretation

The pa per pres ents re sults of petrographic anal y ses of gla cial tills in the west ern part of the Kleszczów Graben and the at tempt of their strati graphic in ter pre ta tion. Petrographic co ef fi cients have al lowed the iden ti fi ca tion of five till lithotypes: T1, T2A, T2 and T2B – as signed to the South Pol ish Com plex (Elsterian) and T4 cor re lated with the Mid dle Pol ish Com plex (Saalian). The well-ex pressed tills that rep re sent the South Pol ish Com plex, oc cur at the bot tom of the sec tion. A new till lithotype, T2B, has been dis tin guished, cor re spond ing to the Kuców For ma tion. It sup ple ments the Pleis to cene lithostratigraphic sec tion of cen tral Po land and cor re sponds to the Sanian 2 Gla ci ation. Among the younger tills, the T4 one (Odranian Gla ci ation) is well de vel oped. The up per most tills of the Wartanian cold stage have been re duced by glaciofluvial and flu vial ero sion. It is, to some ex tent a con se quence of the ex is tence of a de pres sion in this area, called the Szczerców Ba sin. The pa per high lights the in ter pre ta tional dif fi cul ties con cern ing the rank and the num ber of ice sheet ad vances dur ing the Pol ish and Mid dle Pol ish Com plexes in cen tral Poland.