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Luminescence dating of the Volochysk section : a key Podolian loess site (Ukraine)

Fedorowicz S., Łanczont M., Mroczek P., Bogucki A., Standzikowski K., Moska P., Kusiak J., Bluszcz A.

Geological Quarterly

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2018

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Vol. 62, No. 3

729--744

EN

The Volochysk site belongs to important and unique loess sites in the Podolia Upland (W Ukraine) because it contains relatively well-developed loess deposits representing the last and penultimate glacial cycles. This loess-palaeosol sequence consists of pedocomplex S1 (MIS 5) developed on loess L2, and loess L1 (MIS 4-2) with the palaeosols of lower, interstadial rank. In this sequence, different periglacial structures were found, including the largest ones of ice-wedge cast type. Different quartz and polymineral fractions separated from the samples collected in the Volochysk site were dated using luminescence methods (SAR OSL, post-IR IRSL and TL) in three Polish luminescence laboratories in Gdańsk, Gliwice and Lublin. In total, 69 luminescence dating results were obtained for 18 samples. The methodological and research aims were to carry out mutual verification of the obtained dating results as well as to analyse and interpret the differences between them, and to determine the age of distinguished deposit layers and the period of cryogenic activities. The luminescence dates of the sediments, which were deposited during MIS 2, 3 and 4, corresponded fairly well to the ages attributed to these stages. They also indicate the age of periglacial phenomena. However, the TL dates were generally older than the OSL ones, especially those obtained for the sediments deposited during MIS 5 and 6. The results of the research of the Volochysk sequence were compared with those obtained in past years for the loess deposits of the Volhynian Upland (north of Podolia) during similar inter-laboratory analyses conducted to determine their age. The results of OSL datings of the older deposits (MIS 5 and MIS 6) are underestimated irrespective of the used method, and the type (quartz, polymineral) and size of grains. Numerous attempts were made to explain this phenomenon, which, however, give no answer. It was only found that this underestimation corresponded to the equivalent dose value of ~150 Gy.

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Recent studies on the Silurian of the western part of Ukraine

Łuczyński P., Skompski S., Kozłowski W.

Acta Geologica Polonica

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2016

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Vol. 66, no. 3

281--297

EN

The paper summarises the effects of recent studies carried out by a team from the Department of Historical and Regional Geology of the Faculty of Geology, University of Warsaw on the upper Silurian of Podolia (western part of Ukraine). The sedimentary history of the Silurian succession of Podolia is characterised by its cyclic pattern, with shallowing-upward cyclothems. In the traditional interpretation, the occurrence of stromatoporoid beds within each cyclothem marks the deepest (or most open-marine) sedimentary environment within the cycle. According to the results of recent studies, their occurrence is connected rather with a relatively shallow-water environment and with high energy phenomena. A substantial reinterpretation of the main sedimentary processes governing the deposition and facies distribution on the shelf is presented. Particularly, there are recognised and described high-energy sedimentary events repeatedly punctuating the generally calm sedimentation that prevailed in the lagoonal settings, some of which are interpreted as tsunami induced. Further perspectives for studies on the Silurian successions of Podolia are also discussed. The main problem is the precise correlation of particular sections that are scattered over vast distances and developed in similar facies associations.

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Niemirów na Podolu – zapomniany eksperyment urbanistyczny doby stanisławowskiej

Rychkov P.

Kwartalnik Architektury i Urbanistyki

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2015

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T. 60, z. 2

5--22

PL

Czasy ostatniego króla polskiego Stanisława Augusta Poniatowskiego (1764–1795) sprzyjały nowym przedsięwzięciom urbanistycznym. Inicjatywy króla powołały do życia kilka śmiałych projektów, zachęcając do podobnej działalności ambitnych magnatów. Najbardziej odległą od stolicy realizacją jednorodnego zamysłu urbanistycznego była przebudowa podolskiego miasteczka Niemirowa – obecnie centrum rejonowego obwodu winnickiego na Ukrainie. Przebudowa struktury całego miasta była możliwa dzięki udziałowi Wincentego Potockiego, podkomorzego wielkiego koronnego. W końcu lat 70. i na początku 80. XVIII wieku nadano regularny układ przestrzenny miastu, zgodnie ze współczesnymi ideami klasycyzującego urbanizmu. Niestety w ciągu dwóch następnych stuleci charakterystyczne elementy tego projektu uległy stopniowemu zatarciu. Na podstawie mało znanych źródeł archiwalnych podjęto zatem próbę wyjaśnienia historycznych dziejów tego swoistego zabytku sztuki urbanistycznej, dotychczas mało znanego i nieobecnego w studiach nad miastem.

EN

The reign of the last king of Poland, Stanisław August Poniatowski (1764–1795) was a time when new ideas were welcomed and eagerly embraced in urban planning. The monarch supported a number of bold projects and encouraged similar initiatives among the more ambitious of the nobles. Of all the towns where a uniform planning scheme was implemented, the most distant from the capital was the town of Nemyriv in today’s Vinnytsia Oblast in Ukraine. The entire structure of the town was transformed owing to the involvement of Wincenty Potocki, Grand Chamberlain of the Crown. In late 1770s and early 1780s, the town was given a regular spatial arrangement, in line with the then popular ideas of classicist urbanism. Sadly, the centuries which followed have gradually obliterated the characteristic elements of the design. On the basis of little known archive sources, the author makes an attempt at tracking the fate of this one-of-a-kind urban work of art, so far quite neglected in urban studies.

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Regressive-transgressive cyclothem with facies record of the re-flooding window in the Late Silurian carbonate succession (Podolia, Ukraine)

Łuczyński P., Kozłowski W., Skompski S.

Acta Geologica Polonica

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2015

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Vol. 65, no. 3

297--318

EN

The term “re-flooding window” was recently proposed as a time-interval connected with the transgressive stage of present day peri-reefal development. In the analysis presented here, a fossil record of a re-flooding window has been recognized. Nine Late Silurian carbonate sections exposed on the banks of the Dnister River in Podolia (Ukraine) have been correlated base on bed-by-bed microfacies analysis and spectral gamma ray (SGR) measurements. Correlated were sections representing settings ranging from the inner part of a shallow-water carbonate platform to its slope, through an organic buildup. The reconstructed depositional scenario has been divided into six development stages, with the first three representing a regressive interval and the latter three a transgressive interval of the basin’s history. The re-flooding window has been identified at the beginning of a transgressive part of the succession. Surprisingly, it is characterized by an extremely fast growth of a shallow, tide-dominated platform and by deposition of calciturbiditic layers in a more basinal area. The interpreted succession is a small-scale model illustrating the reaction of carbonate depositional sub-environments to sea level changes and determining the facies position of the stromatoporoid buildups within the facies pattern on a Silurian shelf. The use of SGR analyses in shallow water, partly high-energy, carbonate facies, both for correlation purposes and for identifying depositional systems, is a relatively new method, and thus can serve as a reference for other studies of similar facies assortment.

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Stromatoporoid beds and flat-pebble conglomerates interpreted as tsunami deposits in the Upper Silurian of Podolia, Ukraine

Łuczyński P., Skompski S., Kozłowski W.

Acta Geologica Polonica

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2014

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Vol. 64, no. 3

261--280

EN

Tsunami deposits are currently a subject of intensive studies. Tsunamis must have occurred in the geological past in the same frequency as nowadays, yet their identified depositional record is surprisingly scarce. Here we describe a hitherto unrecognized example of probable palaeotsunamites. The Upper Silurian (Pridoli) carbonate succession of Podolia (southwestern Ukraine) contains variously developed event beds forming intercalations within peritidal deposits (shallow water limestones, nodular marls and dolomites). The event beds are represented by stromatoporoid and fine-grained bioclastic limestones, in some places accompanied by flat-pebble conglomerates. The interval with event beds can be traced along the Zbruch River in separate outcrops over a distance of more than 20 km along a transect oblique to the palaeoshoreline. The stromatoporoid beds have erosional bottom surfaces and are composed of overturned and often fragmented massive skeletons. The material has been transported landward from their offshore habitats and deposited in lagoonal settings. The flat-pebble conglomerates are composed of sub-angular micritic clasts that are lithologically identical to the sediments forming the underlying beds. Large-scale landward transport of the biogenic material has to be attributed to phenomena with very high energy levels, such as tropical hurricanes or tsunamis. This paper presents a tsunamigenic interpretation. Morphometric features of redeposited stromatoporoids point to a calm original growth environment at depths well below storm wave base. Tsunami waves are the most probable factor that could cause their redeposition from such a setting. The vastness of the area covered by parabiostromal stromatoporoid beds resembles the distribution of modern tsunami deposits in offshore settings. The stromatoporoid beds with unsorted stromatoporoids of various dimensions evenly distributed throughout the thickness of the beds and with clast-supported textures most probably represent deposition by traction. In some sections, the stromatoporoids are restricted to the lowermost parts of the beds, which pass upwards into bioclastic limestones. In this case, the finer material was deposited from suspension. The coexistence of stromatoporoid beds and flat-pebble conglomerates also allows presenting a tsunami interpretation of the latter. The propagating tsunami waves, led to erosion of partly lithified thin-layered mudstones, their fragmentation into flat clasts and redeposition as flat-pebble conglomerates.

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Problem tsunamitów. Dlaczego tak mało jest kopalnych osadów tsunami?

Łuczyński P.

Przegląd Geologiczny

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2012

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Vol. 60, nr 11

598–-604

EN

Tsunami is a common phenomenon and one of the most dangerous natural hazards of the modern world. Taking into account the relative high frequency of tsunamis in historical times, we can expect accordingly rich geological records of similar events from fossil formations. However, palaeotsunami deposits are surprisingly rare, mainly because of the difficulty of discerning them from sediments formed by other processes, e.g. storms. Part of the problem lies in the definition of tsunamite, which refers only to the triggering process, and in a different approach while discerning modern and fossil tsunamites. Modern tsunamites are identified by connecting the deposits to a particular historical tsunami event, even if they contain no diagnostic sedimentological features - an approach, which cannot be applied to fossil formations. This can lead to an impression that modern tsunami deposits are much more common than their fossil counterparts, which in turn suggest great intensification of tsunami events in historical times. Lately, a great number ofpapers have been published on sedimentary effects of modern tsunamis. The studies concentrated on land and near-shore areas. Many authors point out that the sedimentary record left by tsunami is commonly surprisingly mean and with a very low preservation potential. When interpreting fossil successions, the most important features that might indicate their tsunamite genesis are: mixing of material derivedfrom various facial zones, evidence of deep erosion and long transport, and association with other symptoms of seismic activity. The stromatoporoid biostromal accumulations in the Upper Silurian ofPodolia are presented here as possible palaeotsunamite deposits. Thick layers of redeposited stromatoporoids within fine-grained peritidal deposits are interpreted as an effect of onshore transport of this relatively light material during high-energy sedimentary events, such as tsunami. In many ways, the stromatoporoid beds resemble modern accumulations oftsunami-derived boulders.

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Age correlation of loess with other Pleistocene deposits on the basis of TL and OSL dating

Fedorowicz S.

Geochronometria

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2007

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Vol. 27

27-32

EN

The author collected 26 samples from six loess profiles located in Poland and Ukraine and 16 samples from three galcigenic profiles in Lithuania. TL and OSL dates were obtained for the samples. The TL dates were calculated in the Gdańsk University laboratory and the OSL dates were obtained by the Institute of Physics Laboratory at the Silesian Technical University. The dating results were referred to the OSL = f(TL) chart. In respect of luminescent dating results, the Upper Vistulian loess shows a high similarity of TL and OSL dates. It means that loess formation took place in conditions conductive to ensure that solar radiation the grains were exposed to reduce the energy accumulated in them. The TL dates of Middle and Upper Vistulian loess are slightly older than the OSL dates. The largest discrepancies were found in soil sample dates. The analysis of glacigenic profile dates is not unambiguous. The fact that the TL dates are older than the OSL dates may mean that during deposition the conditions were not sufficiently conductive to reduce the energy stored earlier in the grains examined with the TL method. This time could have been sufficient to reduce the energy examined with the OSL method.