Wyniki analizy pyłkowej osadów interglacjalnych w Koczarkach koło Mrągowa

Abstract

Pokład osadów jeziornych (gytia, torfy, mułki, iły) o miąższości ponad 42 m leży na glinie zwałowej zlodowacenia południowopolskiego, a przykryty jest kompleksem glin zwałowych zlodowacenia środkowopolskiego i bałtyckiego. Rezultaty badań osadów jeziornych i bagiennych metodą analizy pyłkowej wykazały obecność flory charakterystycznej dla interglacjału mazowieckiego. Stwierdzenie dwu niepełnych sukcesji pyłkowych z dwoma optimami klimatycznymi sugeruje dwudzielność tego interglacjału. RESULTS OF POLLEN ANALYSIS OF INTERGLACIAL DEPOSITS AT KOCZARKI NEAR MRĄGOWO The region of Mazury was the object of the geological and cartographic investigations of Dr W. Słowański for many years. The samples from the profile Koczarki 2 with intract structure were received by the author (Z. Borowko-Dłużakowa) for the performing of the pollen analysis. Unfortunately, the sudden death of Dr W. Słowański broke the activity of this distinguished geologist, not allowing for the full eleboration of this material. According to the lithological description made by W. Słowański in 1983, the 42,0 m thick bed of the lacustrine and boggy sediments (gyttja, peats, silts, clays more or less sandy, with bands of humus, wood and small remains of fauna) overlays the glacial till of South-Polish Glaciation and is covered by the complex of glacial till of Middle Polish and Baltic glaciations. The results of the pollen analysis reflect the succesive changes in the pollen assemblage zones, preserved in two series: A (depth 175,80-153,60m) and B (depth 150,10-129,95 m). Both series are separated by the bed of sand with gravel (depth 151,5-150,3 m). The pollen zones were separated according to the classification of the interglacial stage by W. Szafer (1953). Zone A - I - (Pinus, Berula, Picea). The decline of the reigning of the pine-birch forest with some addition of spruce (Picea), alder (Alnus), oak (Quercus), linden (Tilia), hazel (Corylus). Ericaceae, Artemisia, Caryophyllaceae, Compositae, Gramineae, Sphagnum are present.Zone A - I I - (Picea, Pinus, AInus). The,reigning of the spruce-pine forest with alder, with the accompanying fir (Abies), oak (Quercus), linden (Tilia), elm (Ulmus) and hazel (Corylus), with the appearance of hornbeam (Carpinus) and Celtis. Zone A - I I I - (Abies, Carpimus, Alnus). The reigning of the fir-hornbeam-alder forest with spruce (Picea), yew (Taxus) and pine (Pinus), with the share of trees and shrubs of the mixed deciduous forest: Acer, Fraxinus, Quercus, Ulmus, Tilia, Pterocarya, Vitis, Corylus, Frangula, Ligustrum, Rhamnus, Viburnum and Hedera,Trapa, Viscum, Osmunda, Azallo filiculoides, Salvinia natans. It is the first climatic optimum. Zone B - I I - (Picea, Pinus, AInus). The reneved development of the spruce-pine-alder forestZone B - I I I - (Abies, Carpinus, AInus). The reneved development of the fir-hornbeam-alder forest. It is the second climatic optimum. Zone B - I V - (Pinus, Betula, Alnus). The beginning of the development of the pine-birch forests with alder. The investigated flora is characterized by the lack of the plants of the arctic climate, what W. Słowański connected with the erosion and denudation of the glacial sediments. The two incomplete floral successions, shown above, are distinguished by the marks typical for Mazovian Interglacial: - the preponderance of coniferous trees (Pinus, Picea, Abies, Taxus) even in the climatic optimum;- the low share of the elements of mixed deciduous forest (UImus, Quercus, Tilia, CoryIus); -the presence of the index plants, Tertiary relics: Celtis, Ilex, Pterocarya, Vitis, Trapa natans, Azolla filiculoides, SaIvinia natans. The analogous succession of pollen zones in the series A and B with two climatic optima in Mazovian Interglacial suggest the bipartite character of this interglacial.