Osady interglacjału eemskiego w Warszawie Odolanach
Abstract
THE EEMS INTERGLACIAL DEPOSITS FROM WARSAW-ODOLANY
Summary
Results of palynological analyses of 10 samples of lacustrine and peat deposits from a borehole made up in Odolany (a quarter of the city of Warsaw) represent an incontinuous floral succession of interglacial character and permit age determination of these deposits. Pollen spectra of sand samples (no. 7, 8, 9 and 10; depth 10,5–13,5 m) are meaningless for stratigraphic interpretation due to contamination from higher part of deposit sequence. Pollen assemblage of siliceous gyttja – sample 6 (depth 9,7–10,5 m) revealed a pine-birch forest with numerous willow and less frequent thermophilous trees: elms, oaks, ashes and hazels. Pollen specter of organic mud – sample 5 (7,9–9,7 m) reveals considerable amount of pollens of oak (35%), pine (28%) and distinctly lesser quantity of birch (20%), while greater portion of elm (3%), ash (3%) and hazel (2%). Low portion of NAP, as well as presence of ivy and hop mark the formation of mixed forest from warming phase of interglacial. This assemblage is correlated with Środoń (16) phytophase Ee of the Eemian Interglacial. Pollen specter of lower portion of peat layer – sample 4 (7,5–7,9 m) is distinct by domination of hornbeam and numerous hazel, line and alder. This is distinctive for phytophase Eg of the Eemian. Pollen assemblage of peat – sample 3 (6,8-7,5 m) clearly marks cooling of climate. The domination of pine (70%) with birch admixture (12%). Abundance of Isoetes microspores (90%) is noted here. Pollen specters of samples 1 and 2 (5,4 and 5,7–6,8 m) contain numerous sporomorphs of synanthropic plants (including cereals). They should be treated as in situ in the sample 1 and thus this sample represents young Holocene deposits. While in the sample 2 infrequent synanthropic pollen grains should be treated as a result of contamination from overlying deposits. The Pleistocene/Holocene boundary would be placed on the boundary between peat and sand layers (6,0 m). The obtained, very simplified picture of floral succesion: Pinus, Betula, NAP ¬– Quercus, Ulmus, Pinus, Corylus – Carpinus, Corylus, Tilia, Alnus – Pinus, Betula, NAP would be interpreted as representing the Eemian Interglacial. In favour of such interpretation could be cited: earlier appearance of oak than hazel, well developed hombeam phase with numerous pollens of hazel and line, and the absence of beech pollens.
Summary
Results of palynological analyses of 10 samples of lacustrine and peat deposits from a borehole made up in Odolany (a quarter of the city of Warsaw) represent an incontinuous floral succession of interglacial character and permit age determination of these deposits. Pollen spectra of sand samples (no. 7, 8, 9 and 10; depth 10,5–13,5 m) are meaningless for stratigraphic interpretation due to contamination from higher part of deposit sequence. Pollen assemblage of siliceous gyttja – sample 6 (depth 9,7–10,5 m) revealed a pine-birch forest with numerous willow and less frequent thermophilous trees: elms, oaks, ashes and hazels. Pollen specter of organic mud – sample 5 (7,9–9,7 m) reveals considerable amount of pollens of oak (35%), pine (28%) and distinctly lesser quantity of birch (20%), while greater portion of elm (3%), ash (3%) and hazel (2%). Low portion of NAP, as well as presence of ivy and hop mark the formation of mixed forest from warming phase of interglacial. This assemblage is correlated with Środoń (16) phytophase Ee of the Eemian Interglacial. Pollen specter of lower portion of peat layer – sample 4 (7,5–7,9 m) is distinct by domination of hornbeam and numerous hazel, line and alder. This is distinctive for phytophase Eg of the Eemian. Pollen assemblage of peat – sample 3 (6,8-7,5 m) clearly marks cooling of climate. The domination of pine (70%) with birch admixture (12%). Abundance of Isoetes microspores (90%) is noted here. Pollen specters of samples 1 and 2 (5,4 and 5,7–6,8 m) contain numerous sporomorphs of synanthropic plants (including cereals). They should be treated as in situ in the sample 1 and thus this sample represents young Holocene deposits. While in the sample 2 infrequent synanthropic pollen grains should be treated as a result of contamination from overlying deposits. The Pleistocene/Holocene boundary would be placed on the boundary between peat and sand layers (6,0 m). The obtained, very simplified picture of floral succesion: Pinus, Betula, NAP ¬– Quercus, Ulmus, Pinus, Corylus – Carpinus, Corylus, Tilia, Alnus – Pinus, Betula, NAP would be interpreted as representing the Eemian Interglacial. In favour of such interpretation could be cited: earlier appearance of oak than hazel, well developed hombeam phase with numerous pollens of hazel and line, and the absence of beech pollens.