POT CASTS IN THE UPPER MUSCHELKALK (MIDDLE TRIASSIC) OF WEIMAR THURINGIA - COMPOSITION, MICROFABRICS AND DIAGENESIS/

A horizon with pot casts (potholes) is described from shallow-marine l imestones of the spinosus-zone ('Discitesschichten', Upper Muschelkalk ) near Weimar/Thuringia. The erosional structures are not developed as sole marks but occur as isolated structures. They differ distinctly i n size and composition from pot casts described from the Muschelkalk o f Southern Germany. Vertical sedimentary zonation and varying sediment infill in the structures suggest continuous erosion and deposition co ntemporaneous with the background sedimentation. Deposition may have b een caused by oscillatory and unidirectional flows as well as a long p eriod of micrite deposition. Early diagenetic deformations (e.g. dewat ering, brecciation, pressure solution) have controlled by a higher con tinuous water flux inside the pot casts and higher intergranular dispe rsal pressure.