Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
A new site of Eemian organogenic deposits in S3up (central Poland) has revealed an intermittent record of several phases within this interglacial. Pollen based studies of the core S3-19, drilled at the littoral zone of the palaeolake, indicated the absence of the E2, E3, E6 and an incomplete record of the E4 and E5 zones of the typical pollen succession. Results of other proxies (plant macrofossils, Cladocera, molluscs, NPPs, isotopes) supported the conclusions derived from the pollen diagram regarding the high humidity and lake water level during the E4 (Corylus-Quercus-Tilia) phase and at the beginning of the E5 (Carpinus-Corylus-Alnus) phase, when the fossil lake was most extensive. Thus, the lack of a record of the E3 and E4 RPAZs was associated with water level lowering and a less humid climate. The results stand in agreement with several other Eemian records from central Poland.
EN
In the northern Lublin region, the Eocene amber-bearing association has been recognized. It is a group of clastic deposits in which amber crumbs are scattered, and the characteristic feature of the association is the content of glauconite. The sedimentological and lithofacies studies allowed determining the conditions necessary for amber deposition. Accumulation of amber-bearing sediments took place in the Middle and Late Eocene. The Upper Eocene formations in this area occur in isolated patches. Amber accumulations are found in marine sediments associated with regressive facies, usually in depressions of the Cretaceous basement. Understanding the correct distribution of amber in the sediment and determining the dynamics of the Eocene sedimentary basin in the Lublin region have a practical aspect, and are the basis for developing the characteristics of the geological economic conditions for the occurrence of amber-bearing deposits. The recently drilled boreholes confirmed amber resource prospectivity in the Lubartów area and the recognition of new deposits with amber reserves.
EN
Our high-resolution data of pollen and macrofossils from 2 cores taken from the Jagodne site (Garwolin Plain) reveals a pollen succession covering the final part of the Late Saalian (Marine Isotope Stage MIS 6) and embracing the Eemian (MIS 5e). The results correspond to Regional Pollen Assemblage Zones (RPAZ). The hornbeam phase (E5 RPAZ) has been subdivided into subzones and compared to the corresponding division of the key profile of the Garwolin Plain, Kozłów K2-19. The comparison revealed a considerable sedimentary hiatus in the E5 RPAZ at Jagodne. This is attributed to significant palaeohydrological changes occurring widely in this zone, and also seen at other Eemian sites in Poland. Another specific feature of the Jagodne site is the early, rapid terrestrialisation of the palaeolake and its transformation into a raised bog, which occurred already at the end of the hornbeam phase. The Sphagnum dominated peatbog developed for a long time as evidenced by a thick peat layer covering also the Early Vistulian. Both pollen and plant macrofossil data correspond well to observed lithological boundaries, providing a consistent record of palaeoenvironmental and palaeoclimate changes. The results obtained contribute to knowledge of palaeoenvironmental changes and palaeoclimate interpretation of that area.
EN
Lacustrine sediments representing Marine Isotope Stage 11 (MIS 11) were found in Hermanów (SE Poland) in a present-day closed depression under a thin cover of Weichselian and Holocene deposits (1.4 m). These sediments filled a palaeolake created as a result of melting of a dead-ice block at the end of MIS 12. Geological research has excluded the presence of an ice sheet during MIS 12 in this area. The lobe of the ice sheet of this glaciation was located several kilometres to the west of Hermanów. The palaeolake was part of a larger palaeolakeland in southeastern Poland, formed during MIS 11. The palaeomorphology of this interglacial is evident in the contemporary relief of the area and the outline of the lakes corresponds to the pattern of the closed palaeodepressions. Based on the record of sediments from Hermanów, a new perspective regarding the sub-division of MIS 11 is presented. Two regressive phases are observed in the Holsteinian Interglacial (MIS 11c) - OHO and YHO. The subsequent substages with five cold fluctuations according to the newest stratigraphic standards should be assigned to MIS 11b with a very clear cooling and a slightly warmer MIS 11a. Carbon isotopic composition of organic matter corroborates geological and environmental analysis. The isotopic composition suggests two cooling periods: OHO and MIS 11b. Stable climatic conditions with little temperature fluctuations persisted between the cooling periods.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.