The differences in grain-size distribution, mineralogical and chemical composition are regarded as confirmation of the crucial role of compositional characteristics in determining the stratigraphy of these tills. The stratigraphy and distribution of tills in the Saadj rve Drumlin Field proves an accretionary origin of these drumlins. They started to form during Saale glaciation and the formation process lasted for several glacial advances. XRD analysis shows that phosphatic pebbles and Mickwitzia valves from the Kakum e Beds consist of apatite, pyrite, and quartz. The lattice parameter a of F-apatite ranges from 9.345 to 9.367 and c from 6.881 to 6.887 .
Pebbles contain the same apatite variety.
Although the valve sculpture is variously preserved, the shell structures appeared to be lost. Shells consist of apatite-cemented quartzose silt and sand. The observed structure and mineral composition have formed via phosphatization of a primarily organic-rich shell. Fraxinus was first recorded about 6500 BP from East Estonia. Carpinus is a late immigrant which reached Estonia in the Sub-Boreal.