In the ‘Winterswijksche Steen- en Kalkgroeve’, situated in the eastern Netherlands, Lower Muschelkalk limestones are quarried. A ca. 30 m wide area in the quarry face showing fragmented rock material in chaotic accumulation in between stratified Muschelkalk sediments was interpreted until now to be the result of karstification or tectonic fragmentation. The present investigation indicates that it originated as a subrosion pipe fill that formed by continuous upsection collapse which commenced in the Röt gypsum and anhydrite beds more than 200 m below. The pipe fill is dated probably to one of the Quarternary interstadials when these rocks were dissolved by groundwater at even greater depths.

A small faunule of fragmentary Hettangian (earliest Jurassic) psiloceratoid ammonites collected from dark-coloured, clay-rich sediments in a subrosion pipe at Quarry III of the Winterswijk quarry complex is described. The genera Alsatites, Saxoceras and Schlotheimia are determined by comparison to extensive literature on coeval, north German faunas. Taphonomic features are apparent indicating condensation and reworking. Despite this, the portion of the subrosion pipe sediment fill which yielded this material can be dated as middle to late Hettangian.