Wyniki wyszukiwania - Biblioteka Nauki

1

Strategic priorities of renewable energy sources for united territorial communities

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Mandryk O. M. , Arkhypova L. M.

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tom Vol. 3, nr 2

89--95

EN

The article deals with the problem energy diversification will significantly reduce the energy dependence of Ukraine, increase the level of economic, national and environmental security and, accordingly, promote economic growth. While studying the sources concerning renewable energy in Ukraine and the legislative framework for renewable energy development a range of issues and benefits, both technical and economic, were outlined. The article is proposed the development of scientifically based information provision for environmentally safe use of renewable energy sources in the Carpathian region for sustainable well-balanced development of united territorial communities will be confirmed by the positive results of increasing the use of environmentally friendly technologies by 30% in the next 5 years from the micro-levels of individual farms to the macro levels of renewable energy sources implementation strategies within the united territorial communities.

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Recognition of geological structures at Starunia palaeontological site and vicinity (Carpathian region, Ukraine) based on gravity surveys

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Porzucek S. , Madej J.

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tom Vol. 79, No 3

357-363

EN

In the early 20th century, relics of Pleistocene mammals were found near the village of Starunia. Gravity surveys performed in the place of the discovery revealed a low-density bed in the Miocene Vorotyshcha salt-bearing beds. The lowered density resulted from high halite content and probably an increased number of ozokerite veins. The localization of zoological relics can be attributed to the existence of this bed. Surface gravity surveys enabled scientists to determine its course and horizontal range. Gravity surveys also confirmed the existence of the Rinne fault. In the western part of the study area gravity modelling showed an interface between Miocene Vorotyshcha salt-bearing beds and Sloboda Conglomerates, differing in average bulk density. Geologic data indicate that this interface may have the form of an overthust rather than of a fault.

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Upper Pleistocene and Holocene deposits at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

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Sokołowski T. , Stachowicz-Rybka R. , Woronko B.

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tom Vol. 79, No 3

255-278

EN

An abandoned ozokerite mine (= Ropyshche), where large mammal remains were discovered in the first half of the 20th century, is located in the Velyky Lukavets River valley covered with Quaternary sediments. The catchment area includes a flysch sequence unconformably overlain by salt-bearing Lower Miocene molasses of the Vorotyshcha beds. Both the Upper Pleistocene and Holocene are represented by: channel (gravel, sandy gravel) and overbank alluvium (mud, peat, biogenic mud) and colluvium (mud, sandy mud) as well as by mine wastes. The channel sediments are usually found in the lowest fragments of the borehole logs and represent mainly material deposited in the straight segments of meandering river-beds. The most common, fine-grained (Mz = 61.33 to 7.11 ?m), distal floodplain sediments are locally up to 10 m thick and are dominated by massive mud lithofacies, which contain frequent burrows, root hairs or slightly larger root traces and reed rods. These sediments are characterized by rather stable grain size distribution, quite monotonous mineral composition, presence of resistant heavy minerals and quartz grains with traces of chemical weathering. Angular grains with conchoidal fractures and sharp edges also occur. Therefore, textural features show that the main sources of material were, most probably, weathering crusts of various ages developed on relatively poorly lithologically diversified Carpathian flysch strata and on Miocene deposits of the Carpathian Foredeep. With time, an increase of the content of material originating from mechanical weathering (frost action) occurred in the floodplain deposits, which can be linked to an increase of climate severity and reduction of vegetation. However, these changes are not recorded in the deposits, which developed mostly in closed hollows and accumulated mainly from suspension or from low-energy flows. This calm sedimentation was periodically interrupted by supply of more coarse-grained material (sand, gravel). A distinct predominance of overbank deposits in the sections documented by their thickness suggests that the northward flow of the Velyky Lukavets River was blocked as a result of either neotectonic movements or damming of the valley by landslide tongues. From the lithological point of view, the most favourable conditions for preservation of large, extinct mammals still exist in the two selected areas, where the total thickness of Pleistocene muds exceeds 2 metres. The first area is located in the vicinity of boreholes Nos 2, 3, 21, 22, 23, 28, 30 33 and 36N, and the other, smaller one, is placed around borehole No. 42.

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Development of relief of the Velyky Lukavets River valley near Starunia palaeontological site (Carpathian region, Ukraine)

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Sokołowski T.

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tom Vol. 79, No 3

243-254

EN

In Quaternary sediments filling the Velyky Lukavets River valley, at the abandoned ozokerite mine (= Ropyshche) in Starunia, perfectly preserved carcasses of large mammals were discovered in the first half of the 20th century. The study area includes a fragment of the valley between Molotkiv and Starunia, and its close vicinity. The area belongs to several morphostructural and geomorphic units of the Outer Eastern Carpathians and the Carpathian Foreland. The asymmetric, subsequent valley is a part of the Mizhbystrytska Upland, where flattened ridges and flat bulges represent fragments of planation surfaces: the upper (the Krasna level), elevated 170 m above the valley bottom and linked with the Late Pliocene, and the lower one (the Loyova level), rising at 100 m and linked with the Eopleistocene. Several flat surfaces are visible on valley slopes, probably representing river terraces formed before the Late Pleistocene. The valley attained its maximum depth during the Eemian Interglacial (OIS 5e). In the Ropyshche area, probably three terrace steps built of Weichselian and Holocene sediments (OIS 5d - 1) were developed, but their top surfaces are almost completely destroyed by mining operations. The recent, meandering river bed follows the zones of decreased cohesiveness of rocks resulting from mining activity and is becoming somewhat deepened during inundations. The transported material is mostly coarse-clastic one. The two latter factors may suggest that the river is underloaded due to declining agriculture and decreasing intensity of outwash. The top surface of the sub-Quaternary basement is deformed by subsidence and collapse of mine workings, but the relief of valley bottom allows for further exploration for remnants of large mammals not only in the Ropyscche area but along the whole studied segment of the valley, as well.

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Detection of near-surface geological heterogeneity at Starunia palaeontological site and vicinity (Carpathian region, Ukraine) based on microgravity survey

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Porzucek S. , Madej J.

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tom Vol. 79, No 3

365-374

EN

Results of a microgravity survey performed in the abandoned Starunia ozokerite mine (Carpathian region, Ukraine), where in the early 20th century well preserved remains of large, extinct mammals were found, are discussed in the paper. A number of gravity anomalies indicating the geological heterogeneity at the sub-Quaternary strata have been observed. The assumed measurement observations also enabled the authors to interpret the results in view of density changes in the Quaternary strata. Most of the registered microanomalies coincide with the high-halite and ozokeritic Miocene salt-bearing Vorotyshcha beds. The distribution of the microanomalies reveals neither their correlation with the thickness of overburdens, nor any gravity impact of numerous abandoned wells. Gravity anomalies were mostly connected with the lithology of sediments and rocks obtained from geological boreholes drilled in the years 2007 and 2008, on the basis of which the anomalies' origin could be determined. A concentric, relatively negative gravity microanomaly of ca. 25 m in diameter was registered in the place, where very well preserved relics of the woolly rhinoceros had been found. They may be indicative of the existence of Pleistocene lakes (and/or palaeoswamps), into which the woolly rhinoceroses had sunk. Hence, an assumption can be made that the further search for successive zoological relics can be made in areas with similar anomalies under the low-density sub-Quaternary subcrop.

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Radiocarbon dating of plant remnants in Quaternary sediments at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

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Kuc T. , Różański K. , Stachowicz-Rybka R.

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tom Vol. 79, No 3

289-296

EN

Radiocarbon dating applied on several occasions in the past to date animal bones and animal soft tissue originating from the area of the Starunia palaeontological site turned out to be very controversial. Although investigations of Pleistocene flora in the Starunia area go back to the beginning of the 20th century, no published 14C dates of such material are available to date. Sixteen boreholes drilled in the area of the Pleistocene mammals discoveries, in the framework of a multidisciplinary research project (2006-2009), have been selected for radiocarbon dating of plant macrofossils. Moreover, five samples of plant remnants extracted from two outcrops in the area were 14C-dated. The nature of the dated plant material, in some cases soaked with oil, posed specific methodological problems. Although applied chemical treatment of macrofossil samples led to complete removal of contaminating hydrocarbons in the case of small pieces, some ageing effects in terms of radiocarbon dating cannot be completely ruled out. Radiocarbon ages of macrofossil samples originating from the close neighbourhood of the location, where the "second" woolly rhinoceros was found at a depth of 12.5 m, suggest that the minimum age of sediments in which the Pleistocene mammals were found is in the range of ca. 35-40 ka BP. A broad consistency between palynological reconstruction of Younger Dryas/Preboreal boundary and the corresponding radiocarbon ages of macrofossils is observed for locations, where the natural sedimentary sequence for late Glacial and early Holocene was not disturbed by extensive mining activity in the area.

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Interdisciplinary studies at Starunia palaeontological site and vicinity (Carpathian region, Ukraine) in the years 2006-2009: previous discoveries and research, purposes, results and perspectives

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Kotarba M. J.

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tom Vol. 79, No 3

219-241

EN

The discovery of large Pleistocene mammals in 1907 and 1929 in the Starunia ozokerite mine, about 130 kilometres southeast of Lviv, Ukraine, was a spectacular scientific event on a world scale. A unique combination of brine and oil, into which the animals had sunk, resulted in the near perfect preservation of woolly rhinoceros. In 2004, investigations in Starunia were restarted by Polish and Ukrainian scientists. This issue of Annales Societatis Geologorum Poloniae contains 18 papers which present the results of field and laboratory studies in the Starunia area completed by Polish scientists in the years 2006-2009. Interdisciplinary studies were realized by eleven thematic working groups on: Quaternary lithology and sedimentology, palaeobotany (palynology and analysis of macrofossils), botany (analysis of halophytes), palaeozoology (malacological analysis), radiocarbon dating, microbiology, surface and near-surface geochemistry, organic geochemistry (bitumen content and its fractions, biomarkers and stable carbon isotopes) and inorganic geochemistry (chloride ion analysis), geoelectric survey (DC resistivity soundings, electromagnetic terrain conductivity measurements, resistivity imaging, penetrometer-based resistivity profiling and azimuthal pole-dipole DC resistivity soundings) and microgravimetric survey. Results of these studies enabled recognition of the geological setting and sedimentary environment of Quaternary sediments, which hosted the Pleistocene fossils, and to determine the most favourable area of about 1,000 square metres for subsequent prospecting for extinct mammals within Pleistocene sediments in Starunia.

8

Microbiological characteristics of Quaternary sediments at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

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Barabasz W. , Chmiel M. J. , Ostafin M.

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tom Vol. 79, No 3

439-446

EN

The microbiological research on the area of the palaeontological site in Starunia (Ukraine) reveals the details of biological activity of the near-surface layers and Quaternary sediments. In Starunia area remnants of a mammoth and three woolly rhinoceroses, and one almost completely preserved rhinoceros carcass were found in 1907 and 1929. The gained quantitative results regarding the occurrence of different physiological groups of microorganisms show that their number varied significantly depending on the sampling place, sampling depth, pH, humidity and the organic matter content. The amount and differentiation of the tested groups of microorganisms typically decreased with the depth. In several deep-sampling locations there was increase in the microorganisms, especially with methanogens and methanotrophs. The metanogens occurred mainly in Pleistocene sediments, comprised of clayey mud and peat, while saprophytic microorganisms (bacteria, fungi and actinomycetes) occur in Holocene sediments comprised of clayey mud, peat and peat mud. The quantity of microorganisms in selected boreholes was related to high concentration of the organic matter (mainly peat and peat mud) and correlated with methane occurrence.

9

Chronostratigraphy and changes of environment of Late Pleistocene and Holocene at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

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Sokołowski T. , Stachowicz-Rybka R.

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tom Vol. 79, No 3

315-331

EN

This paper presents the results of absolute dating and biostratigraphical analysis carried out for alluvial sediments of an abandoned Starunia ozokerite mine located in the Velyky Lukavets River valley, in which large mammal remains were discovered in the first half of the 20th century. The sediments build up three terrace levels. The highest one, up to 8 m high (terrace II), is likely to be associated with a stage of aggradation, as well as with a short episode of valley broadening, which occurred in the Weichselian Late Pleniglacial. The lower one, 4 m high (terrace I), is most likely to be linked with the Holocene, despite a considerable transformation of its top due to mining activity. The lower part of this terrace cover bears coarse-grained channel sediments dated to 120.6-58.9 ka BP (Eemian Interglacial?-Early Pleniglacial - OIS 5e, 4 and 3), and overbank (distal floodplain) mud with intercalations of biogenic deposits (peat, peat mud and biogenic mud). The overbank deposits are dated to 48.2-11.11 ka BP (Glinde Interstadial?-Younger Dryas, OIS 3-2) and are overlain by Holocene (OIS 1) mud and biogenic deposits. In boreholes drilled in the vicinity of the present-day river channel, younger sediments occur more frequently. These include sediments originating from the Late Weichselian overlain by Holocene sediments. However, sediments originating exclusively from the Holocene are infrequent. The deposition of sediments took place in specific conditions of a permanent saturation of the environment with brine, petroleum and thickened bitumen. In the longest period of deposition (48.2-1.27 ka BP), ephemeral swamps, ponds and lakes were developed in different parts of the floodplain. They were marked by the presence of: Juncus glaucus/effusus, J. articulatus, Typha sp., Batrachium sp., Potamogeton filliformis, Bidens tripartita, Ranunculus sceleratus and Phragmites communis, as well as by halophytic species, like: Zannichellia palustris, Triglochin maritimum, Schoenoplectus tabernemontani, Puccinelia distans and Eleocharis palustris. Rhythmic oscillations between cold and warm climatic conditions, typical of the Weichselian age and well identified in Western Europe, are here marked by the changes of plant communities (woody assemblages passing into steppe and tundra), but are not noticeably recorded in the sediments of the Velyky Lukavets River. This shows that the greatest part of the discussed period involved the formation of poorly differentiated silty overbank sediments with intercalations of biogenic sediments. However, the variability of sediments provides evidence for extreme events which occurred in the Holocene.

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Bitumen and salt contents within the Quaternary sediments at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

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Kotarba M. J. , Więcław D. , Toboła T. , Zych H. , Kowalski A. , Ptak S.

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tom Vol. 79, No 3

447-461

EN

Geochemical studies were conducted on bitumen and salts saturating the Pleistocene and Holocene sediments from an abandoned ozokerite mine in Starunia. This location is noted for the discovery of remnants of a mammoth and three woolly rhinoceroses in 1907, and a nearly completely preserved rhinoceros carcass in 1929. The bitumen (oil) and brines (chloride ions) were preserving agents for the large Pleistocene mammals. The main mass of organic carbon hosted in the Pleistocene muds is related to bitumen originating from oil migrating from deep accumulations within the Boryslav-Pokuttya Unit. The highest analysed bitumen content is 9.26 wt%. The chloride ion content, originating from highly concentrated brines ascending from the salt-bearing Miocene Vorotyshcha beds, vary from 0 to 4.66 wt% but this usually does not exceed 1 wt%. The natural pathways of underground fluids (oil, gas and water) migration within the Quaternary sediments were disturbed by intensive ozokerite mining operations run between the last three decades of the 19th century and 1960. Therefore, the present preservation and conservation conditions of large, extinct mammals' remains can be different from those prevailing during the Pleistocene, when the mammals were buried. Taking into consideration the contents of the remaining preservatives: chloride and bitumen, the most favourable zone for fossils conservation and preservation is located close to boreholes Nos 22, 23, 28 and 36N, where the thickness of Pleistocene muds exceeds 2 metres. Generally, the spatial distributions of bitumen and chloride ion contents within the Holocene sediments and salt-bearing Miocene Vorotyshcha beds are very similar to those in the Pleistocene sediments.

11

Parameters determination of a conceptual rainfall-runoff model for a small catchment in the Carpathians

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Karabova B. , Sikorska A. E. , Banasik K. , Kohnova S.

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nr 2

EN

One of the most important tasks in hydrology is to simulate and forecast hydrologic processes and variables. To achieve this, various linear and nonlinear hydrologic models were developed. One of the most commonly applied rainfall-runoff models is the Nash’s model of the Instantaneous Unit Hydrograph (IUH) (Nash, 1957) used jointly with the CN-NRCS method. Within this paper, the Nash’s model was applied to a small forested basin (Vištucký Creek, Slovakia) to reconstruct rainfall-runoff events based on the recorded precipitation. The Vištucký Creek catchment, located in the Little Carpathians, is a part of the flood protection management of regional sites in the Little Carpathians. Therefore, the object of this paper is, first, to determine the parameters of a conceptual rainfall-runoff model for the Vištucký creek catchment, second, to analyse how the selected characteristics of the model depend on the rainfall characteristics, and third, to compare obtained results with a similar study of Sikorska and Banasik (2010). The computer programme developed at the Dept. of Water Engineering (WULS-SGGW) was used to obtain the rainfall–runoff characteristics based on the Nash´s model. The derived characteristics were parameters of the Nash’s model (N, k, lag time) and rainfall-runoff characteristics (sum of total and effective precipitation, rainfall duration, runoff coefficient, time to IUH peak, value of IUH peak, goodness of fit). A relatively small effective precipitation from the rainfall events was derived. For the purpose of the analysis, a correlation between the lag time (and k parameter) and the sum of the total and effective precipitation was used. The use of the conceptual rainfall-runoff model (Nash´s model) for the small catchment in Carpathians was proved to give satisfactory results. The rainfall characteristics derived in this study are comparable to the results obtained by Spál et. al (2011), who used the same catchment in their analysis. Interestingly, our analysis indicated that there is a correlation between the rainfall duration and the lag time, what is opposite to the compared results of Sikorska and Banasik (2010).

PL

Jednym z ważniejszych zagadnień w hydrologii jest matematyczne symulowanie i prognozowanie procesów hydrologicznych, które musi być poprzedzone wyznaczeniem parametrów stosowanych modeli. Do matematycznego opisu procesów opad-odpływ w małych zlewniach opracowano szereg modeli liniowych i nieliniowych o różnym stopniu złożoności. Jednym z częściej stosowanych jest model liniowy, w którym opad efektywny wyznaczany jest wg metody CN (Curve Number), stosowanej w Służbie Ochrony Zasobów Naturalnych (Natural Rsources Conservation Service) Departamentu Rolnictwa USA, a do transformacji opadu efektywnego w odpływ bezpośredni wykorzystywany jest chwilowy hydrogram jednostkowy (IUH) wg Nasha. Model ten zastosowano do odtworzenia zdarzeń opad-odpływ w małej leśnej zlewni górskiej Vištucký Potok w Małych Karpatach w zachodniej Słowacji. Celem przeprowadzonych badań było, po pierwsze - wyznaczenie parametrów zastosowanego modelu, na podstawie dziewięciu zarejestrowanych zdarzeń opad-odpływ w okresie 2005-2010, po drugie - zanalizowanie zależności parametrów modelu od charakterystyk deszczu, i po trzecie - porównanie wartości charakterystyk zdarzeń opad-odpływ i parametrów modelu z wynikami podobnego opracowania podobnego opracowania wykonanego dla zurbanizowanej zlewni Potoku Służewieckiego w Warszawie (Sikorska i Banasik 2010). Do wyznaczenia charakterystyk na podstawie zarejestrowanych zdarzeń opad-odpływ, parametrów modelu oraz do wyznaczenia hydrogramu "regenerowanego" i określenia parametrów jego zgodności z hydrogramem obserwowanym, wykorzystano program komputerowy SN opracowany w Katedrze Inżynierii Wodnej SGGW. Uzyskano zbieżność wyników w odniesieniu do parametru CN (wartości średniej z analizowanych zdarzeń z wartością tablicową - ustaloną we wcześniejszych badaniach na podstawie rodzaju gleb i użytkowania terenu badanej zlewni) oraz stosunkowo małą zmienność czasu opóźnienia - Lag (iloczyny parametrów modelu Nasha: N i k). Stosunkowa mała wartość parametru CN i współczynnika odpływu wynika z leśnego użytkowania zlewni. Uzyskano bardzo słabe zależności pomiędzy parametrami modelu i charakterystykami opadu. Porównanie wyników analizy zdarzeń opadowych w obydwu zlewniach potwierdza znacznie zróżnicowanie parametru CN oraz wskazuje na małe różnice w czasie opóźnienia, determinowanego użytkowaniem, topografią i wielkością powierzchni zlewni.

12

Salinity of Quaternary sediments and halophytes at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

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Mościcki W. J. , Toboła T. , Zarzyka-Ryszka M.

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tom Vol. 79, No 3

391-402

EN

Interdisciplinary geophysical, geochemical and botanical studies were performed to recognize the problem of salinity of Quaternary sediments in the place, where woolly rhinoceroses were discovered at the beginning of the 20th century. Geoelectric methods (high resolution geoelectric research with electromagnetic conductivity meter) enabled construction of maps of the distribution of conductivity of near-surface sediments. Variation of conductivity with depth was recognized with penetrometer-based geoelectric measurements. Measured conductivity mainly depends on the level of mineralization (salinity) of underground water filling the pores and voids of poorly consolidated Quaternary sediments and partly underlying Miocene strata. Several samples were taken from geological boreholes. The analysis of these cores enabled estimation of salt (chloride ion) content in the solid phase of sediments. This content varies from place to place and with depth in an unpredictable way. The highest values reached 8.5 wt%. Generally, on the basis of a qualitative comparison, the salinity data gained from sampled cores correlate with distribution of apparent conductivity obtained with geoelectric methods. Nevertheless, in some places there is a discrepancy between geophysical and geochemical data, especially for penetrometer versus borehole data. It may be partly explained by an unavoidable difference in location of the geological borehole and penetrometer site (technically this cannot be the same place). During botanical field studies a group of vascular plants growing on saline soils (halophytes) was found. Halophytes indicate a higher salt concentration in the soil. Their aggregations are extremely rare in the Carpathian region. The pattern of halophytes distribution reflected the presence of saline water sources, and their flows and soils affected by them. Generally, the distribution of halophytes showed a good correlation with the distribution of high-conductivity anomalies determined with the surface geoelectric survey.

13

Biological markers and stable carbon isotope studies of bitumen impregnating Quaternary sediments at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

63%

Kotarba M. J. , Fabiańska M. , Więcław D. , Kowalski A. , Zych H.

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tom Vol. 79, No 3

463-480

EN

Biological markers and stable carbon isotopic compositions of bitumen impregnating the Pleistocene and Holocene sediments around the Starunia palaeontological site (Carpathian region, Ukraine) near discovered remnants of a mammoth and three woolly rhinoceroses, and one almost completely preserved rhinoceros carcass found in 1907 and 1929, were investigated. The research was carried out to assess genetic connections between the bitumen and oils from the nearby deep accumulations of the Boryslav-Pokuttya and Skyba units of the Carpathians. Another aim of these geochemical studies was to reveal the secondary geochemical processes (oxidation and biodegradation) influencing the bitumen, and to determine which environments have been favourable or unfavourable for the preservation of large Pleistocene vertebrates. Bitumen included within the near-surface rocks are not genetically connected with residual organic matter present in Quaternary sediments. Geochemical features, such as distributions of pentacyclic triterpanes and steranes, biomarker parameters and isotope composition indicate that all bitumens originate from oil-prone, Type II kerogen with insignificant admixture of terrestrial Type III kerogen in the middle stage of catagenesis. The oils occurring in deep accumulations in the Starunia area were the sole source of bitumen found in the near-surface sediments. Input of immature organic matter to bitumen from Pleistocene and Holocene sediments has not been found. The main factors differentiating the bitumen were: biodegradation, water washing and/or weathering. Additional influence of transport of bitumen by brine was found. The most favourable conditions for preservation of large, extinct mammals within the Pleistocene muds exist in the vicinity of Nos 22 and 23 boreholes, where bitumen is best preserved. The worst conditions were found in the vicinity of Nos 1, 4, 4' and 15 boreholes. Intensification of biodegradation and weathering effects were followed by intensive, chaotic changes of the remnants of large Pleistocene mammals.

14

Surface geochemical survey at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

63%

Sechman H. , Kotarba M. J. , Dzieniewicz M.

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tom Vol. 79, No 3

375-390

EN

A surface geochemical survey was carried out in an abandoned ozokerite mine in Starunia, where remnants of a mammoth and three woolly rhinoceroses and one almost completely preserved rhinoceros carcass were found in 1907 and 1929. In total, 689 measurement sites were defined within the selected 300×350 m rectangle (ca. 10.5 ha). The analysed soil gases vary in their molecular and isotopic compositions. Several zones with anomalous methane concentrations over 10 vol% were identified in the study area. These anomalous concentrations correlate well with total C2-C5 alkane anomalies (over 1 vol%). The zones with carbon dioxide concentrations over 15 vol% are generally shifted SW of those, where the methane and the sum of C2-C5 alkanes anomalies were identified. High helium concentrations of crustal origin (over 0.001 vol%) are clustered near fault zones. In a majority of cases methane is of thermogenic origin, migrating to the near-surface zone from deep-seated accumulations. Microbial methane, or methane with a high microbial component, is genetically related to recent swamps. The high variability of concentrations of gaseous components together with the highly variable isotopic composition of individual gases in the soil, indicate their thermogenic and/or microbial origin, and point to the lithological diversity of Quaternary sediments in the study area. Several zones with thermogenic gaseous hydrocarbons and helium were delineated. It is likely that during the Pleistocene winters, under a thick ice and snow cover, the tundra lake and swamp zones around outflows of brines, oil, helium and thermogenic gases had a higher temperature, which resulted in melting and cracking of the ice cover. These sites would be more prospective for future search of well-preserved large vertebrates.

15

Molecular and isotopic compositions of gases adsorbed to near surface sediments at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

63%

Dzieniewicz M. , Sechman H. , Kotarba M. J.

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tom Vol. 79, No 3

421-437

EN

The near-surface geochemical survey of gases desorbed from sediment samples was carried out in the area of an abandoned ozokerite mine in Starunia, where remnants of mammoth and three woolly rhinoceroses and one almost completely preserved rhinoceros carcass were discovered in 1907 and 1929. Numerous hydrocarbon seeps (gas and oil "eyes") occur on the surface of the study area. Analyses of molecular and stable carbon isotope compositions of adsorbed gases were carried out in two variants. The first included sampling of cuttings from 30 auger boreholes at depths of 4.8, 5.6 and 6.4 m. In total, 88 samples were collected. In the second variant core samples were collected from 17 selected boreholes. In total, 78 samples were taken from various depths to 12 m. The results of molecular composition analyses of desorbed gases indicated high saturation of near-surface sediments with the oil. The highest concentrations of alkanes were detected in Miocene strata. Hydrocarbon migration from deep accumulations to the surface was relatively fast and proceeded along the faults, fractures and cracks. In the near-surface zone hydrocarbons were subjected to oxidation and dehydrogenation, which resulted in generation of unsaturated hydrocarbons and hydrogen. These processes were most intensive in the Pleistocene sediments and in the mine dumps. Increased concentrations of hydrogen may also originate from water radiolysis in the presence of hydrocarbons. Concentrations of carbon dioxide in the adsorbed gases show the higher values in comparison with the analysed gaseous compounds. However, a slight increase in CO2 concentration was detected in the mine dump, which may indicate conditions more favourable for hydrocarbon oxidation. Carbon dioxide from the analysed adsorbed gases is of thermogenic origin. Occasionally, insignificant influence of secondary hydrocarbon oxidation and/or Quaternary organic matter can be observed. Concentrations of alkanes, alkenes and carbon dioxide in the gas derived from desorption of rock samples are lower and the concentration of hydrogen is higher than those measured in free gases. This indicates that additional effects from recent (e.g. microbial) processes are absent.