Recognition of the loess covers by using a resistivity imaging method

A main aim of research work was to recognize loess covers by geoelectrical method for three tipped areas, to define loess thickness and show their variability. Resistivity imaging method was used. To research chose Kańczuga Plateau, Nałęczów Plateau and Prydniestrov’ja region (Ukraine). There were used resistivity imaging methods, and the work results were corelated with geological documentation of the research area. The research showed variability in loess covers related to their stratigraphy and allow determine thickness loesses deposit

Rate of loess accumulation in Europe in the Late Weichselian (Late Vistulian)

The European loess profiles provides evidence of changes in climate in the last glacial cycle. The final stage of loess accumulation took place in the youngest part of the last glacial (28 to 12 ka BP). Loess accumulated in two periods: from 28 to 18 ka BP and from 18 to 13 ka BP. These two stages were separated by a short phase of weaker aeolian activity and weak pedogenesis (initial tundra gleyed soils). The loess sedimentation rate can be defined as a mass accumulation rate (MAR ex pressed in g/m2/year). This value was calculated by Frechen et al. (2003) for several dozen loess sites across western and central Europe. In this paper we calculate the MAR for several loess sites in Poland and Ukraine. The MAR distribution across Poland and Ukraine is uneven in these two intervals. The MAR values oscillate between 100 to several thou sand g/m2/year. They markedly in crease eastwards, which may be explained by the latitudinal gradient of periglacial climate in the LateWeichselian (= Late Vistulian). The MAR distribution along a N-S trend confirms its large range in western and central Europe. However, the most easterly profiles (Polish and Ukrainian ones) show less variable thick nesses as the MAR was stable at a relatively low level from several hundred to more than a thou sand g/m2/year. This stability of the MAR characterized both loess-forming intervals in this part of Europe

High-resolution terrestrial archive of climatic oscillations during Oxygen Isotope Stages 5-2 in the loess-palaeosol sequence at Kolodiiv (East Carpathian Foreland, Ukraine)

The Kolodiiv section is situated in the central part of the East Carpathian Fore land, on the right bank of the Sivka River, the Carpathian tributary of the Dniester River. This paper summarizes investigations on the loess deposit succession representing the Late Pleistocene, which is subdivided by several interstadial palaeosols and is bracketed by the last interglacial soil/organic deposits and Holocene soil. The Kolodiiv loess-palaeosol sequence provides an excellent high-resolution terrestrial archive of changing climate during OIS 5-2 in the East Carpathian Fore land and forms the basis for a regional pedo- and loess stratigraphy. The stratigraphic scheme was constructed on the basis of palaeosol occurrence, lithological variation in the deposits, and also the results of TL dating and palaeomagnetic in vestigations. The exposure at Kolodiiv contains an archaeological site with Middle Palaeolithic materials. Four types of palaeopedological taxa have been distinguished within the loess deposit at Kolodiiv: an interglacial (Eemian) soil unit, which includes one or two soil-forming episodes; interstadial palaeosols, which include two weaker soil-forming episodes; thin interstadial two-horizonpalaeosols; monogenetic incipient palaeosols. Palaeosols from the first and second group form the Horohiv soil unit correlated with OIS 5. Palaeosols from the third and fourth group occur as different soil types within the Dubno 1 and 2 units, which correspond to OIS 3

Palaeomagnetic studies of the loess-palaeosol sequence from the Kolodiiv section (East Carpathian Foreland, Ukraine)

The Upper Pleistocene loess-palaeosol sequence from the Kolodiiv section (East Carpathian Fore land) has been palaeomagnetically studied. Almost all samples displayed moderate to high positive palaeomagnetic inclinations and declinations en closed between 320° and 40°. How ever, one sample from the fossil soil of the last inter glacial pedocomplex (at 16.6 m pro file depth) was reverse magnetized and there fore can be correlated with the Blake Palaeomagnetic Event. Consequently that palaeosol can be related to (Oxygen Isotope Stage) OIS 5e1. An other sample from the Dubno 1 interstadial palaeosol demonstrated southern declination and significant lowering of inclination (up to 40°). This might be a record of the Laschamp Palaeomagnetic Event or of any Late Pleistocene palaeomagnetic excursion. The magnetic susceptibility and anhysteretic remanent magnetization data reflect the presence of several soils forming during the warm conditions of OIS 5 and the complex nature of the Eemian warming. Two palaeosols that developed between ca.115 ka and 120 ka indicate at least two climatic optima during the Eemian. High values of magnetic susceptibility (up to 300 Ą 10-6 SI units) noted in the middle of the section that contains slump deposits (9.5 m to 11m of depth) suggest that this material was derived from older soils of inter glacial type

Vistulian litho- and pedosedimentary cycles recorded in the Kolodiiv loess-palaeosol sequence (East Carpathian Foreland, Ukraine) determined by laser grain-size analysis

In the Kolodiiv site, occur ring in the valley of the Sivka River (tributary of the Dniester River, Ukraine), Vistulian loess forms a subaerial cover over the Pleistocene terrace II. This terrace consists also of Eemian deposits (palaeosol or organic sediments) under lain by an alluvial succession of Wartanian age. The Kolodiiv 2 profile was studied in detail in order to reconstruct the conditions of loess accumulation, and consequently the climatic-environmental changes, that took place in this region. Eight lithogenetic units were distinguished in the profile: five trans formed by pedogenesis, and three loess beds. The main purpose of this study was to conduct a thorough examination of the units lithology, in particular the grain-size distribution, in order to investigate those loess-forming factors that are influenced by environmental changes (i.e. nature of source material, distance and dynamics of transport, type of deposition and redeposition, and hypergenetic processes). To achieve this, 174 samples were taken at 10 cm spacings along the profile, and the grain-size distributions of the deposits were determined using a laser method with 21 grain-size intervals examined in each sample and statistically analyses. Statistical analysis included: calculation of the main grain-size parameters (according to Folk and Ward's method), grain-size index (Ding etal., 1994) and also two statistical tests (Kolmogorov-Smirnov and Spearman rank correlation) applied in order to find differences or similarities between the grain-size distributions of the lithogenetic units distinguished. Stratigraphic variations in grain-size distribution reflect the division of the deposits into stratigraphic units previously arrived at. Mean values of grain-size index (Igs1) indicate that loess units 2, 4 and 6, differ from the palaeosol units 3, 5 and 7. The grain-size distribution of loess deposits in the Kolodiiv 2 profile varies, with marked dominance of the silt fraction, which indicates that these deposits were trans ported by winds of similar velocities carrying material a short distance from source. As the Aeolian conditions that formed loess deposits in the Kolodiiv 2 profile were generally stable, differences in the grain-size distribution of unit 2 representing the Upper Pleniglacial, suggest three cycles of loess deposition during that interval (with the middle cycle characterized by the most distinct, short-term oscillations in environmental dynamics). The variability in grain-size distribution in units 3-5, which to get her represent the Interplenivistulian (Middle Pleniglacial), reflects the climatic heterogeneity of this period. The palaeosol layers are diamictic. Higher values of grain-size indices show that all Upper Pleistocene palaeosol units of high (interglacial) and low (interstadial) rank are characterized by higher content of fine relative to coarse fraction the lowest mean values of grain-size index occur the soil unit 1, of Holocene age, suggests that this unit is probably a product of very recent, Neoholocene pedogenesis and does not represent the en tire Holocene epoch. The statistical tests results show, great similarity between loess units 2 and 4 (from the middle and upper part of the Pleniglacial), and also between palaeosol units 7 and 8 forming the Horohiv slpalaeosol unit (an Eemian palaeosol and interstadial palaeosols from the Early Vistulian). Further more, the individual nature of loess unit 6, deposited during the Lower Pleniglacial, seems to be associated with the climatic characteristics of this interval

Mousterian artifacts from the unique Vistulian loess-palaeosol sequence at Kolodiiv (East Carpathian Fore land, Ukraine)

The remains of a Mousterian cultural layer were found on the solifluction horizon at kolodiiv, Ukraine, separating two Early Vistulian palaeosols. The geological position of the finds and the typological characteristics of the assemblage allow us to refer this site to the bifacial techniques of the "East-Micoquian Route of Development"

Geochemical composition of Vistulian loess and micromorphology of interstadial palaeosols at the Kolodiiv site (East Carpathian Foreland, Ukraine

This paper summarizes geochemical and palaeopedological investigations of the Upper Pleistocene loess-palaeosol sequences at the Kolodiiv site. The Kolodiiv 2, 3 and 5 profiles were selected for this study. The Kolodiiv 2 profile contains loesses, interglacial (Eemian) and interstadial (Vistulian) palaeosols. A set of Early Vistulian soils over lying Eemian gyttja and peat is exposed in the Kolodiiv 3 and 5 profiles. The mineral composition of the 50-2 mm silt fraction was analysed using non-oriented powder samples by means of X-ray dif - fraction. The total concentrations of nine major (Si, Ti, Al, Fe, Mn, Mg, Ca, K and Na) and nine trace elements (Zn, Pb, Ni, Rb, Cr, Sr, Ba, Co, V) as well as the humus content and loss on ignition were measured. The major elements concentrations in mineral deposits from the Kolodiiv 2 loess-palaeosol sequence indicate that the loess particles were derived from poorly weathered source rocks that have under - gone at least one sedimentary cycle. Climatic conditions have strongly in fluenced the mobilization and accumulation of elements in the palaeosol horizons due to the changes in the intensity of weathering and pedogenic processes. For the micromorphological study, ten samples from the Kolodiiv 3 and 5 profiles were used. Thin sections representing the Kolodiiv and Dubno set of palaeosols from Early Vistulian and Middle Pleniglacial show, be sides palaeopedologic characteristics, significant evidence of redeposition of sediments and soils

Stratigraphy and sedimentology of the Bug loess (Pleistocene: Upper Vistulian) between Kiev and Odessa (Ukraine)

Documented type sections (Vyazivok, Stayky, Uman, Troitskoye, Altestovo, Roxolany and Lebedivka) provide a basis for Pleistocene stratigraphy between Kiev and Odessa, and have been used to characterise the heavy mineral composition and part of the light fraction of the Bug loess in this area. These sections document an almost complete succession of climatic change during the last 780 ka, worked out mostly using loesses and palaeosols though also in the case of the first two sections, of glacial deposits. The heavy mineral composition of the Bug loess in these sections documents five mineral groups on the basis of their resistance to weathering and susceptibility to deflation and aeolian transport. Radar charts with particular mineral groups indicate mineralogical and genetic trends in the loesses. Moreover, in some sections the light fraction of the loess investigated contains derived microfossils (mainly foraminifers) of Cretaceous age, indicating source areas for the loess-forming material, and constraining the palaeowind directions. The data obtained allow distinction of three accumulation zones of the Bug loess in this area, reflecting loesses derived from different source areas and transported by winds from different directions. In northern sections (zone A), the Bug loess was accumulated by winds blowing from the west and north-west. More to the south (zone C), the same loess was accumulated by winds from the east and south-east. Loess preserved in zone B, between these areas, could be accumulated by winds from either of these directions

Stratigraphic interpretation of loess in the marginal zone of the Dnieper I ice sheet and the evolution of its landscape after deglaciation (Dnieper Upland, Ukraine)

Litho-, pedo- and palynological analyses constrained by radiometric dating of two loess-palaeosol sequences, Nahirne and Velyka Andrusivka, exposed in a cliff at the eastern edge of the Dnieper Upland, Ukraine, document regional environmental changes in the western marginal zone of the Dnieper lobe. The postglacial loess sedimentation cycle was initiated during MIS 8, immediately after the ice sheet recession. On the basis of palaeorelief analysis, subsequent morphogenetic stages of the original postglacial relief, associated with the modifying and masking role of the loess, and destructive slope processes were reconstructed. Periglacial steppe with consistently present scattered trees formed the Pleistocene landscape in the Middle Dniester area during the last three glacial periods. In such an environment, the following loess beds, correlated with marine isotope stages (MIS), were deposited: Dnieper (dn) - MIS 8, Tyasmyn (ts) - MIS 6, Uday (ud) - MIS 4 and Bug (bg) - MIS 2. During the last two warm periods: Kaydaky (kd) - MIS 7 and Pryluky (pl) - MIS 5, the landscape was not fully forested. As a result, the individual palynological features of these soils show a diverse character. The TL and OSL dates form a sequence with numerous inversions that are difficult to interpret. Although these data do not significantly influence the interpretation, they show that: 1) there are loesses that undoubtedly formed after the maximum extent of the ice sheet by short-distance transport of dust material from local fresh glacial deposits and the underlying Paleogene rocks; 2) date distortions result from the activities of an exceptionally rich pedofauna that has contaminated the material not only in the soil sections of the profile but also in the adjacent loess. It is possible to delimit a few stages of pedofaunal activity in each of the soil units