At least one carapace of the very fragile P. baueri species was found in this horizon. Intact carapaces of this very thin and fragile valved species indicate fluctuating water conditions because P. baueri is known to burrow millimetres into the sediment to avoid desiccation. In combination,this suggests the presence of surfacewater remaining in the lake for short durations only as the result of high-magnitude but lowfrequency
flood events since the mid Holocene (i.e. TL age of 5.5 ka).