scholarly journals Palaeocarpological and palaeoclimatic studies of the murtic interglacial flora of the Belarusian upland

2020 ◽  
pp. 70-77
Author(s):  
Heorhi I. Litviniuk
Keyword(s):  
Climate Changes ◽  
Time Span ◽  
Warm Period ◽  
Fossil Pollen ◽  
Quaternary Deposits ◽  
Palynological Analysis ◽  
Reference Sections ◽  
Pollen And Spores ◽  
Fossil Floras ◽  
Good Agreement

The Muravian interglacial horizon is the last warm period of time span closest to our time, as well as one of the marking horizons in the complex composed layer of Quaternary deposits in Belarus. The study of the Muravian deposits, as well as an elucidation of the paleogeographic conditions that existed at that time, can make it possible to predict climate changes on our planet in the future. Based on the analysis of palaeocarpological materials obtained by the author in the study of reference sections located within the territory of the Belarusian upland and reflecting the optimal phases of the Muravian interglacial, a brief analysis of the composition of fossil floras is carried out, the conditions for their formation are established, and paleoclimatic reconstructions were performed on the basis of the obtained materials. The data obtained indicate that the average July temperatures at the optimum of the Muravian interglacial on the territory of the Belarusian upland were +17.0 till +24.0 °С for the eastern regions and +17.0 till +21.2 °С for the Grodno upland. The average January temperature ranged from +2.0...+7.0 to –3.0...–7.2 ºC. The results obtained are in good agreement with the data of other methods, in particular, palynological analysis based on the study of fossil pollen and spores. In accordance with the modern climatic indicators of the territory of Belarus, the climate at the optimum of the Muravian interglacial was at least several degrees warmer than the current one, and the winters were much milder.

A Late Holocene Paleoecological Record from Torrey Pines State Reserve, California

2000 ◽  
Vol 53 (3) ◽  
pp. 341-351 ◽  
Author(s):  
Kenneth L. Cole ◽  
Eugene Wahl
Keyword(s):  
Late Holocene ◽  
Climate Changes ◽  
Regional Climate ◽  
Sediment Chemistry ◽  
Fossil Pollen ◽  
Plant Type ◽  
The North ◽  
Low Genetic Diversity ◽  
Core Site ◽  
Pollen And Spores

AbstractPaleoenvironments of the Torrey Pines State Reserve were reconstructed from a 3600-yr core from Los Peñasquitos Lagoon using fossil pollen, spores, charcoal, chemical stratigraphy, particle size, and magnetic susceptibility. Late Holocene sediments were radiocarbon dated, while the historical sediments were dated using sediment chemistry, fossil pollen, and historical records. At 3600 yr B.P., the estuary was a brackish-water lagoon. By 2800 yr B.P., Poaceae (grass) pollen increased to high levels, suggesting that the rising level of the core site led to its colonization by Spartina foliosa (cord-grass), the lowest-elevation plant type within regional estuaries. An increase in pollen and spores of moisture-dependent species suggests a climate with more available moisture after 2600 yr B.P. This change is similar to that found 280 km to the north at 3250 yr B.P., implying that regional climate changes were time-transgressive from north to south. Increased postsettlement sediment input resulted from nineteenth-century land disturbances caused by grazing and fire. Sedimentation rates increased further in the twentieth century due to closure of the estuarine mouth. The endemic Pinus torreyana (Torrey pine) was present at the site throughout this 3600-yr interval but was less numerous prior to 2100 yr B.P. This history may have contributed to the low genetic diversity of this species.

scholarly journals Age and Depositional Environment of Walat Formation Based on Palynological Analysis in Sukabumi Regency, West Java, Indonesia

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rizki Satria Rachman ◽  
Winantris ◽  
Budi Muljana
Keyword(s):  
Data Analysis ◽  
Chemical Treatment ◽  
Depositional Environment ◽  
Treatment Method ◽  
Late Eocene ◽  
West Java ◽  
Palynological Analysis ◽  
First Occurrence ◽  
Pollen And Spores

AbstractWalat Formation is equivalent to Bayah Formation. This formation is the beginning of Bogor basin deposition. In this case, age and environment of this formation have been analyzed by previous researchers, but the results of age and environment interpretations have different ranges, especially from its palynological aspect which until now Walat Formation is rarely analyzed using this aspect. This research was conducted to identify the age and depositional environment of Walat Formation in Sukabumi region by using pollen and spores to confirm different interpretations of previous studies. Measure section was carried out in sampling and chemical treatment method was carried out to see palynomorph content in the rock. Furthermore, data analysis was carried out with range of interval zones and pollen grouping based on their environment.The results show that Walat Formation has Late Eocene age based on the interval zone between first occurrence of Verrucatosporites usmensis and Meyeripollis naharkotensis, and the last occurence of Proxapertites operculatus, Proxapertites cursus, and Cicatricosisporites eocenicus. Walat Formation has fluvial depositional environment characterized by the dominance of Proxapertites operculatus and Proxapertites cursus. The results of this study confirm that the Walat Formation has an Eocene age and a fluvial depositional environment from a palinological aspect.

scholarly journals Graptolite dynamics in Silurian and Devonian time

1987 ◽  
Vol 35 ◽  
pp. 149-159
Author(s):  
T. N. Koren'
Keyword(s):  
Environmental Factors ◽  
Sea Level ◽  
Comparative Studies ◽  
Climate Changes ◽  
Environmental Changes ◽  
Time Intervals ◽  
Early Devonian ◽  
Carbonate Sedimentation ◽  
Reference Sections ◽  
Devonian Age

On the basis of biostratigraphic data known at present some preliminary attempts are made to evaluate graptolite dynamics, that is changes in graptolite diversity in time and space within pelagic fades of Si­lurian and Early Devonian age. For the comparative studies of diversity fluctuations versus some major environmental changes a standard graptolite zonation is used. Several critical and more or less well stu­died stratigraphical intervals are chosen; among them the Ordovician/Silurian, Sheinwoodian/Gorstian and Gorstian/Ludfordian boundary beds. For each level the most complete reference sections are analy­zed. Special attention is given to the graptolite extinction, specification and radiation events within these time intervals. They might have been partly connected with or influenced by the environmental factors as a result of eustatic sea-level and climate changes, alteration of anoxic conditions, migration of carbonate sedimentation in pelagic direction, and other globally detectable events. The graptolite evolution during the time of monograptid existence can be subdivided into three phases using the comparison of the ampli­tude of the extinction-origination events and repeatability of the synphasic cycles.

scholarly journals Fossil pollen and spores as a tool for reconstructing ancient solar-ultraviolet irradiance received by plants: an assessment of prospects and challenges using proxy-system modelling

2019 ◽  
Vol 18 (2) ◽  
pp. 275-294 ◽  
Author(s):  
Alistair W. R. Seddon ◽  
Daniela Festi ◽  
T. Matthew Robson ◽  
Boris Zimmermann
Keyword(s):  
Systematic Evaluation ◽  
Fossil Pollen ◽  
System Modelling ◽  
Pollen And Spores ◽  
Ultraviolet Irradiance ◽  
Solar Ultraviolet

A systematic evaluation of the uncertainties limiting the application of UV-B-absorbing compounds in pollen and spores to reconstruct UV-B irradiance.

scholarly journals Distribution and intensity of glaciotectonic deformation in Denmark

1996 ◽  
Vol 42 ◽  
pp. 175-185
Author(s):  
Peter Roll Jakobsen
Keyword(s):  
High Intensity ◽  
Large Scale ◽  
Geological Survey ◽  
Large Impact ◽  
Well Log ◽  
Quaternary Sediments ◽  
Quaternary Deposits ◽  
Shallow Subsurface ◽  
Good Agreement ◽  
Related Morphology

Glaciotectonic deformation has a large impact on the stratigraphical and lithological variability of Quaternary deposits and the shallow subsurface pre-Quaternary sediments. Mapping of the distribution of glaciotectonic deformation involving pre-Quaternary and interglacial deposits has been carried out, and the density of glaciotectonic deformation analysed, on the basis of data from the well database ZEUS, at the Geological Survey of Denmark. Glaciotectonic deformation is widespread in Denmark. It is recognised in glacial terrains within morphological well-defined glaciotectonic complexes, and in areas with no obvious glaciotectonic related morphology as well as in areas covered with postglacial deposits. The dislocated bedrock is usually not transported for long distances, although rafts of pre-Quaternary bedrock may be transported up to 50 km or more. On a large scale, regions have been located showing high intensity of glaciotectonic deformation. Some of these regions are in good agreement with records from exposures and the geomorphology, others cannot be recognised without well log information.

scholarly journals Fossil Pollen and Spores in Japanese Coal

1965 ◽  
Vol 44 (12) ◽  
pp. 792-796
Author(s):  
Shigemoto Tokunaga
Keyword(s):  
Fossil Pollen ◽  
Pollen And Spores

scholarly journals Modeling geologically abrupt climate changes in the Miocene

2010 ◽  
Vol 6 (6) ◽  
pp. 2687-2701
Author(s):  
B. J. Haupt ◽  
D. Seidov
Keyword(s):  
Southern Ocean ◽  
Climate Changes ◽  
Computer Experiments ◽  
Time Span ◽  
Sea Surface ◽  
Central American ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Salinity Changes ◽  
Cooling Trend

Abstract. The gradual cooling of the Cenozoic, including the Miocene epoch, was punctuated by many geologically abrupt warming and cooling episodes – strong deviations from the cooling trend with time span of ten to hundred thousands of years. Our working hypothesis is that some of those warming episodes at least partially might have been caused by dynamics of the emerging Antarctic Ice Sheet, which, in turn, might have caused strong changes of sea surface salinity in the Miocene Southern Ocean. Feasibility of this hypothesis is explored in a series of coupled ocean-atmosphere computer experiments. The results suggest that relatively small and geologically short-lived changes in freshwater balance in the Southern Ocean could have significantly contributed to at least two prominent warming episodes in the Miocene. Importantly, the experiments also suggest that the Southern Ocean was more sensitive to the salinity changes in the Miocene than today, which can attributed to the opening of the Central American Isthmus as a major difference between the Miocene and the present-day ocean-sea geometry.

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