Field of Study – Geology (N 005)

Managing nature during times of rapid environmental dynamics as well as modelling of the future changes, knowledge of ecosystem response to climatic fluctuations throughout the geological past analysed on diachronic (time) and geographic (space) perspective is required. The Quaternary, geological period with typical dynamics of cold and warm climatic intervals, was characterized by significant fluctuations in the palaeoecosystem regime, therefore this geological period is exceptionally important in assessing long-term trends in similar changes. All together that provide more comprehensive insights into the environmental behaviour and is especially important analysing situation in the transitional environmental (glaciated-subglacial), climatic (oceanic-continental) and floristic (boreo-nemoral) zones, where most pronounced fluctuations might have occurred. Insights into the pattern of these changes are crucial to predicting future environmental and climatic regimes. Furthermore, this is very important in modelling the dynamics of future ecosystems or their individual components and in developing tools and methods to prevent undesirable aspects of change.

In the major part of the European territory formation of the modern ecosystems started after the Pleniweichselian Maximum, at about 20 thousand years ago, with the beginning of the degradation of the youngest, Scandinavian, glacier. At that time, the periglacial zone, i.e. territory situated outside the maximum extent of the Scandinavian Ice sheet, are of crucial importance, as numerous processes, including soil formation, forestation and etc., started from these zones to the newly deglaciated areas. Significant number of plants and animals survived cold interval (glaciation) next to the ice sheet establishing to the newly deglaciated areas after the ice retreat of northern and northeaster Europe.

Studies of varying scope, detail and complexity, conducted over many years in the northern, central and western parts of the continent, have made it possible to characterize in quite detail the history of the development of palaeoecosystems after the onset of global warming, including assessing the role of periglacial areas in the formation of ecosystems in glaciated regions (Birks and Birks, 2004; Willis and van Andel, 2004; Giesecke, 2005a,b; Latałowa and van der Knaap, 2006; Margielewski, 2006; Birks and Willis, 2008; Binney et al., 2009). In addition, the main features of the vegetation history, glacier dynamics, soil erosion, etc. in the aforementioned parts of the continent have been described within high chronological reliability (Lowe et al., 2008; Rasmussen et al., 2007; Walker et al., 1999, 2012; Syrykh et al., 2021; Pł´ociennik et al., 2022; Andreev et al., 2021; Salonen et al., 2024). Meanwhile, the eastern part of the European continent is significantly less studied in terms of paleoecosystem knowledge. Moreover, paleoenvironmental dynamics data from regions spanning the eastern part of the continent have highlighted notable discrepancies in the nature, scale, and even chronological allocations of recorded paleoecosystem fluctuations (Wohlfarth et al., 1999, 2002, 2004, 2006, 2007; Subetto et al., 2002; Stančikaitė et al., 2008, 2009; Zernitskaya et al., 2015; Herzschuh et al., 2023; Renssen and Isarin, 2001; Herzschuh et al., 2023). It is obvious that scientific discussions analyzing the history of paleoecosystems across Europe after the Pleniweichselian Maximum require additional detailed, comprehensive studies along the eastern gradient. Alongside with this, knowledge of the interaction of ecosystem components on the various time scales is of vital importance, as these are unlikely to be linear.

Due to the geographical situation of the Ukrainian territory, a major part of the country is attributed to the periglacial zone of the Late Weichselian Glaciation, i.e. was free of ice during the Pleniweichselian maximum, this region provides exceptional opportunities for multi-proxy palaeoenvironmental and palaeoclimatic reconstructions. Meantime region host various types of paleo-records, i.e. lake sediments, peat deposits, marine, delta and fluvial deposits, speleothemes, loess deposits, tree ring, archaeological data and etc. Beside that country is located at the conjunction of Atlantic, Mediterranean and Siberian air masses that determined strong climatic regimes during the various intervals of the geological past. At the same time, the region was characterized by significant biodiversity, which was very important for the survival of both plants and animals or insects in the territory (refugee area) during maximum glaciation and for their subsequent spread into the deglaciated areas. It is obvious that in order to study the history of ecosystem development in the deglaciated areas, it is necessary to understand the “prehistory” of these transformations, i.e. to study the processes and transformations and the causes that determined them in periglacial zones, linking the information obtained with the ecosystem formation processes that took place further north. Obviously, territory of Ukraine might be indicated as a key region constructing central-northeastern-northern European gradient with the further integration of existing databases.

Identification of the palaeoecosystem dynamics applying multidisciplinary (geological, geomorphological, lithological, paleobotanical, isotopic and etc.) approach, alongside the gradient following from the periglacial zone in Ukraine to the eastern Baltic region after the Pleniweichselian maximum (over the past 18-20 thousand years) directly influenced by the glacier, is the main aim of the planned research.

Achieving the main aim of the doctoral studies, it is planned to carry out detailed lithological (LOI, grain-size and MSus), paleobotanical (palynological and plant macroremains) and isotopic (14C) studies in western Ukraine. Based on the information obtained, assessing the vegetation composition, regime of the sedimentological basin and climatic changes in the territory after the Pleniweichselian maximum will be analysed. Availability of the data characterizing the history of palaeoecosystem development in the Ukraine is quite poor i.e. of low stratigraphic resolution, lacking independent chronological information and regional data correlation or interpretation (Kremenetski, 1995; Huhmann et al., 2004; Kalinovych, 2004, 2013; Stachowicz-Rybkaet al., 2009; Kołaczek et al., 2016; Kalinovych, 2004, 2013; Stachowicz-Rybka et al., 2009). The latter fact is particularly important incorporating a new data into European data sets, therefore, the research will emphasize the interpretation of the information obtained in the local and regional context. Also, based on the identified (a)biotic markers we are going to characterize the sedimentary response of lacustrine systems during the periods of climatic shifts of different magnitude. Alongside with this exploration of the vegetation history and sedimentary dynamics will be discussed emphasising pattern of local and regional changes. Summarizing the original research data obtained, the correlation of the obtained data along the NE-W European gradient will be performed, emphasizing the relationship of the identified changes with the fluctuations recorded in the Northern Hemisphere and globally. The application of new available data analysis methods, including statistical information evaluation, correlation and interpretation tools, can significantly contribute to the formation of a modern model of the development of palaeoecosystems based on the assessment of their dynamics.

 Vegetation is a key reservoir of biological diversity on our planet; one of its major ecological, social and economic services. Unfortunately, in the context of the current global crisis it is suffering from both climatic factors and anthropogenic pressure. Anticipating and modelling vegetation response to future challenges needs information on past reactions to similar forcing. Reliable reconstructions of the postglacial vegetation dynamics are crucial improving our understanding of the past ecosystem dynamics giving an opportunity for future scenarios testing.

This project aims to achieve new understanding of the spatiotemporal dynamics of the tree species in the south-eastern margin of the Scandinavian Glaciation throughout the Lateglacial and Holocene combining palaeoecological and genetic approach. To address described challenge, we suggest the high-resolution multi-proxy palaeoecological and palaeo-genomics (molecular) investigations of plant macro remains, including identification of genetic lineages, of the common tree taxa (Pinus, Picea, Betula and etc.). With these data we will assess new information concerning, refugial areas and respective migration routes of the particular taxa, re-colonisation pattern of the deglaciated territories and subsequent formation of the vegetation cover, including identification of the genetic lineages, in the transitional palaeoenvironmental (glacial-subglacial), climatic (oceanic-continental) and floristic (boreo-nemoral) zone, close to the limits of the species natural distribution range. Although numerous plant species have been investigated with regard to their postglacial history incorporation of palaeoecological data and that describing the genetic variations of the particular taxa in the geological past is limited in the Eastern Baltic so far.

Analysis of the obtained data, including the application of the statistical approach, will provide more comprehensive insights into the palaeovegetation behaviour and that is especially important analysing situation in context of both internal and external drivers as well as making future forecast.

The Zhytomyr region of Ukraine has been severely affected by the military conflict. In order to overcome its consequences and ensure sustainable development in line with environmental standards, it is necessary to accurately record, study and assess the extent of the ecological catastrophe, and to develop a system of indicators describing these phenomena. Explosions, fires and accidents of various magnitudes, including incidents at oil storage facilities, have occurred in the study area. The damage caused leads to risks such as erosion, soil contamination, and disruption of geo- and bio-ecosystems.

Contaminants accumulate in the soil and are subsequently released into other environments. The mobility of pollutants in the environment depends on the physicochemical properties of the soil, including its granulometric and mineralogical composition, humus content, cation exchange capacity, pH level, etc. The prediction of contaminant migration can be facilitated by the identification of landscape and geochemical barriers. Planning for the restoration of the geo-environment should take into account the level of pollution, the extent of damage, and the landscape and geochemical conditions that influence the transport of pollutants.

The study will analyse satellite imagery to identify war-damaged areas and assess the extent of damage. Soil samples will be taken in the affected areas to determine concentrations of heavy metals such as mercury, lead, iron, zinc, cadmium, aluminium and copper. These metals are the most frequent sources of contamination to soil from explosive devices. In addition, the presence of sulphur and nitrogen compounds from petroleum products will be assessed. The adsorptive, structural and textural properties of soils and their role in contaminant transport will be investigated, as well as the influence of geochemical barriers on contaminant retention.

The results will be used to develop recommendations to address soil contamination and erosion, as well as to propose monitoring protocols and strategies for the protection of damaged areas.

Managing nature during times of rapid environmental dynamics as well as modelling of the future reaction, knowledge of ecosystem response to climatic changes throughout the geological past analysed on diachronic (time) and geographic (space) perspective is required. Alongside with this, knowledge of the interaction of ecosystem components on the various time scales is of vital importance, as these are unlikely to be linear. All together that provide more comprehensive insights into the environmental behaviour and is especially important analysing situation in the transitional environmental (glaciated-subglacial), climatic (oceanic-continental) and floristic (boreo-nemoral) zones, where most pronounced fluctuations might have occurred.

Being the crucial component of the ecosystem, vegetation is a key reservoir of biological diversity on our planet; one of its major ecological, social and economic services. Therefore, anticipating and modelling vegetation response to future challenges information on past reactions to external forcing is highly required. Interglacials, pronounced warm climatic events, that often lasted for thousands of years, could shed important light on the vegetation history and future trends subsequently. Hereby, intercorrelation of vegetation trends and subsequent complex analysis of the information, representing different interglacials, may enhance our knowledge about the spatiotemporal dynamics of the vegetation along the long-lasted time axis.

During the last decades palaeoebotanical disciplines have collected relevant, site-specific pollen and plant macro data representing two warm geological intervals, interglacials, named Holocene (present) and Eemian (previous) Interglacial of the Upper Pleistocene in the eastern Baltic. Analysis of the obtained data, including the application of the statistical approach, will provide more comprehensive insights into the palaeovegetation behaviour and that is especially important analysing situation in context of both internal and external drivers as well as making future forecast.

This PhD study project aims at the spatiotemporal reconstruction of the long-lasted vegetation dynamics throughout the warm intervals of the Upper Pleistocene (Eemian-Holocene) in the Eastern Baltic applying integrated statistical approach and providing remarkable input into the global knowledge of forest dynamics and potential future changes.

Realizing the objectives of the PhD studies, alongside with the involvement of rich palaeobotanical data set, classical statistical methods and programs (Statistica, PAST and etc.) together with the modern ones, i.e. R programmes and multivariate analysis (PCA, DCA, tb-PCA and etc.), including various modelling techniques (GLM, GLMM, GAM ir kt.), will be applied.

Alongside with this development of a new research agenda is going to be realised.

Scapolitization as a leading process in ore formation is very common in skarn and IOCG-type deposits. The unique property of scapolite to incorporate halogens, CO₂ and SO₂ from the fluid in equilibrium allows this mineral to be used as a fluid composition proxy. Thus, the halogen ratios of Br/Cl and I/Cl can be utilised to infer the origin of the fluids. However, at high-grade conditions fluid phase may experience a variety of processes such as low-pressure devolatization, salt nucleation, fluid immiscibility etc., that can lead to halogen fractionation and hence, data misinterpretation. To avoid these pitfalls, a detailed chemical composition of scapolite formed in prograde to retrograde conditions is needed. The Varena Iron Ore Deposit (VIOD) presents a unique chance to track fluid evolution under the changing geological conditions since scapolite here can be found in a variety of rock types, linked to prograde, peak and retrograde conditions at varying fluid/rock ratios.

To determine the origin and evolution of the fluid in the VIOD, scapolite formed at different stages will be linked to rock-forming mineral assemblages using optical and Scanning Electron (SEM) microscopy. An EMPA chemical analysis and major element mapping will be performed to classify the scapolites in terms of their chemical composition. Moreover, the halogen and REE content will be analysed using a LA-ICPMS in selected grains that represent a prograde-to-peak-to-retrograde loop. Temperature estimations will be performed using classical thermometers where possible and further constrained via thermodynamic modelling performed on metapelites found to the East of the VIOD.

The acquired data will provide evidence for the fluid source(s). The previous research results indicate the presence of Cl-rich fluid at the peak conditions; however, its origin remains unclear (seawater, evaporites, and mafic igneous rocks). The earliest-formed scapolite should provide the best approximation of the fluid origin. Changes in the halogen ratios at different stages will illustrate either the mixing of the sources or possible halogen fractionation. The composition and evolution of the fluid are crucial for the ore remobilization and accumulation.

Candidates for this PhD position should have a good understanding of fluid chemistry and phase transitions, and be familiar with thermodynamic modelling software (Perplex, TheriakDomino etc.).