Stratigraphy of the Callovian in the Wieluń Upland

Abstract

The stratigraphic analysis of the Callovian strata in the Wieluń Upland (Central Poland) shows that the stratigraphic gaps comprise the upper part of the calloviense Zone and jason, athleta and mariae zones. The gaps recorded in the Lower and Middle Callovian may be best explained by an increase in the rate of erosion in relation to sedimentation. The gap comprising the athleta Zone depends moreover on some paleogeographic factors, such as widening of the basin and some increase ID its depth, and a drop in supply of terrigenous material not compensated by carbonate deposition. The analysis of some species of the subgenus Kepplerites (Gowericeras) made it possible to assign the forms hitherto treated as two separate species, K. (Gowericeras) gowerianus (Sowerby) and K. (Gowericeras) toricelli (Oppel), solely to the former one.