ALBERT

Description: 1. This paper deals with a pollenanalytical investigation of holocenic peat-layers in Central Friesland. 2. One diagram shows a praeboreal spectrum with Betula in the dominant position, the first appearance of thermophilous trees (Corylus, Alnus) and a high percentage of Gramineous and Cyperaceous pollen. 3. Originally in all diagrams the percentages of Ericaceous pollen are low. 4. During the boreal time the peat formation was of little importance. A maximum of Corylus pollen in the boreal period has not been found here. 5. In the Atlanticum a thick layer of peat has been formed; the percentage of Alnus pollen remains high, the Quercetum-mixtum fluctuates between 10 and 25 per cent and there is also much Corylus pollen. 6. Two narrow clay-bands are present in the peat. They contain many pollen grains of halophytic plants, which indicates that there must have been two marine transgressions in the Atlanticum. These transgressions will have reached their farthest point in this region. 7. In the upper atlantic and subboreal peat-layers there are many fragments of Ericaceae and also a high percentage of Ericaceous pollen. 8. The Young Sphagnum peat consists of Sphagnum species of the Cymbifolia section. The presence of Fagus pollen never reaches a level of 10 per cent. 9. During the subatlantic transgression the Young Sphagnum peat has locally been washed away and was replaced by clay with many Phragmites rests. The author wishes to express his thanks to “It Fryske Gea”, the Frisian association for the protection of nature, president Mr. M. WIEGERSMA, Drachten, for the permission to take samples at “Het Princehof” and for the assistance to this work. He is also highly indebted to Dr. F. P. JONKER for his assistance and interest during the investigation and to Prof. Dr. C. E. B. BREMEKAMP for correcting the English text.