Fig. 2. A Description of lithography and varve quality of core K10, Lake Van.  Colour description of the sediment was made 3-5 hours after opening the core.  ML gives the position of the Marker Layer.  B. Modified pollen profile from lake Van made by Van Zeist (1978 a).  Reliable stratigraphic correlation is possible only at the ashlayers because samples were taken from two different cores.  Vertical distance between samples is 10 cm.  In most samples more than 1000 pollen grains and spores were counted.