Field of Study – Geology (N 005)
A meeting of the Commission for Admission to Doctoral Studies in the Field of Geology (N 005) with participation of applicants (motivational interviewing) will be held at the Conference Hall of Nature Research Centre on 13 September, 14:00 P.M. (online available too). Motivational interviewing will be conducted on the topic the applicant selected for his/her doctoral studies and thesis; applicants are recommended to deliver a 10 min duration PowerPoint presentation and give a brief review of planned research and scientific achievements. The interview and presentation will be evaluated taking into consideration the applicant’s scientific competence (publications, participation in scientific research projects and conferences), motivation in selecting the topic of the thesis, and primary methodological skills.
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.
The main problems faced by modern people are sustainable and renewable energy, which would be an alternative to fossil fuels, and possible ways to decrease atmospheric CO2 level. In Lithuania geological subsurface architecture and lithological composition give the chance to assess possible applicability for geothermal energy exploitation as well as CO2 storage. Geothermal energy is becoming an important source of energy due to the limited and gradual depletion of hydrocarbon resources. Western Lithuania shows elevated heat flow that is the prerequisite for geothermal energy production. The major geothermal aquifers in Lithuania are related to sandstones of Cambrian and Devonian. Also, Cambrian sandstones are the main hydrocarbon reservoir in the Baltic sedimentary basin with producing oil fields from several decades. All three horizons are characterized by good or very good reservoir properties, however, with comparatively poorer reservoir quality in Cambrian sandstones due to enhanced digenetic quartz cementation and compaction. Still, Cambrian depleted oil fields and brine-saturated sandstone reservoir may be also considered as CO2 storage target. In both cases, i.e., geothermal energy and CO2 storage, the geological characterization of reservoir is a key aspect in order to reduce the risks associated with reservoir volume and seal quality, however, the mineral composition of the reservoir rock is also fundamental. In case of geothermal energy utilization, knowledge on minerals composing the sediments may clarify questions linked to possible clogging processes during the exploitation of geothermal water. While, in case of CO2 storage, based on petrological properties of reservoir rocks the mineral sequestration potential (therefore identification of the most reactive mineral phases in terms of carbonation of CO2) can be assessed, which, in turn, is linked to sedimentary facies and, thus, depositional environment. The main goal of the study is to characterise petrophysical, petrological properties of Paleozoic rocks rocks of Lithuania as well as to establish their depositional environment.
The objective of the study will be to identify trends in the sediment petrological features and their provenance in order to enhance reservoir quality characterization.
The main tasks would be the following: 1) to collect porosity, permeability, clay content and other petrophysical properties data; 2) to analyse rocks for new porosity, permeability, clay content and other petrophysical properties data 3) to compare the porosity data obtained by different techniques (well-logs and laboratory); 4) to compile porosity and clay content variation cross-sections; 5) re-evaluation of existing geological data gathered during the petroleum exploration/development; 6) establish sedimentary facies / microfacies from the core observations, analysis of thin section and geophysical well logs; 7) determine sediment mineralogical composition by XRD, optical microscopy and scanning electron microscopy; 8) determine heavy mineral composition of the rocks.
Expected results – the study of of porosity, permeability, clay content and other petrophysical properties is expected to reveal spatial variation of petrophysical properties. Which Paleozoic periods (systems) have better reservoir properties will also be established. Modern and up to date geological-geophysical data interpretation software will be used in the study and enable better data interpretation and visualization. This study will provide new information on sediment provenance area, mineral assemblages and other petrological features that would allow interpretation of the depositional environment. This information together with identification of rock diagenetic alteration will contribute to more complete characterization of sandstone reservoir quality in respect to geothermal or CO2 storage potential assessment.
Rare metal granites (RMG) are chemically distinct type rocks, characterized by their enrichment in volatiles and fluxing elements (e.g., F, Li, and/or P, B), as well as disseminated mineralization of Li, Sn, Nb and Ta. Often RMGs are highly fractionated, scattered throughout large areas as pegmatitic and aplitic veins. The distribution of mineralization is strongly controlled by fractional crystallization, changes in physicochemical conditions, tectonic setting of emplacement and late-stage alterations.
Such granites of peraluminous affinity are found in the southern part of Lithuania, where they are temporally and spatially associated with the Mesoproterozoic AMCG complex. According to Linnen and Cuney (2005), these granites can be classified as peraluminous low phosphorus (PLP) granites. However, scarce research on these rocks has been performed thus far and their economic potential remains unknown.
This proposal aims to develop a comprehensive model for this granitic body emplacement and to ascertain its economic potential. The main task of this research is to assess the petrological and geochemical character of the granitic rocks and determine their distribution and physical conditions of emplacement (T, P, fO2 and fluid composition in terms of F/OH, Cl/OH ratios). For this, various igneous thermobarometers will be applied (Ti in zircon, Bt, Hbl, Ilm-Mag thermobarometers etc.) together with detailed chemical mineral analysis and whole rocks composition, employed as petrological indicators and mineralization proxies.
The candidates for this position should possess a good understanding of igneous petrology and mineral chemistry. Good English skills are mandatory.