Vol 32(1) 2019

2019 m.

Santrauka An article is devoted to the passion of ‘Baltica’ Edition – from the Yearbook – established in 1961, published first in 1963, and renewed in 1993 – to the present International Journal on Geosciences of the Baltic Sea and the circum-Baltic States, the story that follows 25 years of Academician Algimantas Grigelis editorial work. The article presents some thoughts about a role of regional journal(s) for science and society, it makes a short historical overview, reports an effectiveness of editorial system, notes tireless efforts for a high contents quality as a main tool for its international evaluation and publicity.

Doi https://doi.org/10.5200/baltica.2019.1.1

Raktažodžiai Baltic Sea; geology; geosciences; international journal

Pilnas tekstas

Santrauka A multi-temporal digital terrain models [DTM] study of a coastal cliff section at Kaszuby Coast (northern Poland) is presented in this paper. The analytical study was based on five LiDAR-derived DTM acquired between 2010 and 2016. The main idea was to compare changes year by year or every two years (depending on the available material). The DTM were analysed using various geoprocessing techniques, and as a result the map of slope and the gradient of maximum changes in z-value were prepared. The analysis of the temporal variations of these parameters were also prepared and allowed to visualize and track the landslides that occurred within the cliff. What is more, the areas of sediment increasement and decreasement, as well as the average rates of vertical displacement within the landslides and sediment balance on the beach were estimated. The studies allowed also to discuss the interrelation between the mass wasting processes and the protective infrastructure on the seashore. The information gathered allows us to find the mechanisms and development of landslides on the steep cliff coast.

Doi https://doi.org/10.5200/baltica.2019.1.2

Raktažodžiai cliff coast; landslide monitoring; northern Poland; land-sea interaction

Pilnas tekstas

Santrauka The continuous research on anthropogenized coastal zones determined qualitative and quantitative characteristics of aliphatic hydrocarbons in the Curonian Lagoon and the Nemunas River Delta. The concentration of aliphatic hydrocarbons varied from 9.1 to 187.6 μg g−1 d.w. The Curonian Lagoon could be classified as a slightly contaminated water basin with some moderately polluted areas, while both rivers and Lake Krokų Lanka were found to be slightly contaminated with aliphatic hydrocarbons. The prevailing unresolved complex mixture and geochemical markers suggested the existence of mixed biogenic-anthropogenic aliphatic hydrocarbon sources in the area studied. The biogenic impact was found to be more pronounced in Lake Krokų Lanka, the south-eastern part of the Curonian Lagoon and in the River Minija, while the Nemunas River Avandelta demonstrated the highest loading of anthropogenic hydrocarbons. The same trends were confirmed by the principal component analysis.

Doi https://doi.org/10.5200/baltica.2019.1.3

Raktažodžiai transitional water; aliphatic diagnostic ratios; hydrocarbon sources

Pilnas tekstas

Santrauka The thick-bedded, deep-water sandstone succession was described at the Tylmanowa site from the Polish Outer Carpathians. This part of the Carpathians is built mainly of the Upper Jurassic to Paleogene deep-water rocks. Succession at the Tylmanowa site is composed of massive, ripple-cross laminated, planar and trough cross-stratified, horizontally laminated and deformed sandstones as well as massive and horizontally laminated mudstones. All these sediments derived from gravity flows that prograde downslope from a basin margin towards the widespread abyssal plain. Exposed succession records the gradual transition from a decelerating debris flow to a turbidity current what is extraordinary in the recent investigations of deep-water sediments. The study succession has been compared with the widely known sediment models, such as: the classic Bouma Sequence (Bouma 1962), the high-density turbidite model (Lowe 1982), the fluxoturbidite model (Ślączka, Thompson 1981) and the hybrid event bed model (Haughton et al. 2009).

Doi https://doi.org/10.5200/baltica.2019.1.4

Raktažodžiai fluxoturbidites; hybrid event beds; sediment-gravity flow; Eocene; Carpatian Flysh Belt

Pilnas tekstas

Santrauka The scope of the study was to assess the impact of potential sources of Cu, Zn, Co, Ni, and Cr on bottom sediments of the Russian sector of the south-eastern Baltic Sea. A total of 68 samples were taken and analyzed for grain-size (laser diffraction and sieve method) and heavy metal concentration (atomic absorption spectroscopy method). To avoid the influence of the sorption capacity of the fine-grained sediments to accumulate the pollutants, the normalization of the heavy metal concentration to Fe was applied. The environmental indices (contamination factor and modified degree of contamination) were calculated. The research has shown the contribution of oil platform, pipelines, ports and wastewater treatment facilities on the geochemical composition of bottom sediments. The authors have identified the level of heavy metals contamination of the middle parts of the Curonian and Vistula spits as a result of alongshore transport of pollutants.

Doi https://doi.org/10.5200/baltica.2019.1.5

Raktažodžiai heavy metals; bottom sediments; normalization; environmental indices; Russian sector of the Baltic Sea

Pilnas tekstas

Santrauka An extraordinary variation of plastic and brittle deformation structures with periglacial, glaciotectonic and seismic features was observed within the unconsolidated, upper Pleistocene meandering river succession in the Slinkis outcrop in central Lithuania. Among these deformations, the following structures were described: (1) ice-wedge casts in the lower part of the sedimentary succession, linked to periglacial processes, (2) soft-sediment deformation structures, such as load structures (load casts, pseudonodules), flame structures and water/sediment-escape structures, all trapped in clearly defined layers in the upper part of the sedimentary succession, which are related to the propagation of seismic waves, and (3) faults occurring throughout the sedimentary succession, which are associated with glaciotectonic processes. To our knowledge, this is the first description and analysis of the combined presence of such a diverse range of deformation features caused by three trigger mechanisms in a meandering fluvial sedimentary succession.

Doi https://doi.org/10.5200/baltica.2019.1.6

Raktažodžiai soft-sediment deformation structures; brittle deformations; seismite; periglacial features; glaciotectonic deformations; liquefaction; meandering river deposits

Pilnas tekstas

Santrauka We model the change of Coulomb Failure Stress (δCFS) during the Weichselian glaciation up until today at 12 locations in Latvia, Lithuania and Russia that are characterised by soft-sediment deformation structures (SSDS). If interpreted as seismites, these SSDS may point to glacially-induced fault reactivation. The δCFS suggests a high potential of such reactivation when it reaches the instability zone. We show that δCFS at all 12 locations reached this zone several times in the last 120,000 years. Most notably, all locations exhibit the possibility of reactivation after ca. 15 ka BP until today. Another time of possible activity likely happened after the Saalian glaciation until ca. 96 ka BP. In addition, some models suggest unstable states after 96 ka BP until ca. 28 ka BP at selected locations but with much lower positive δCFS values than during the other two periods. For the Valmiera and Rakuti seismites in Latvia, we can suggest a glacially-induced origin, whereas we cannot exactly match the timing at Rakuti. Given the (preliminary) dating of SSDS at some locations, at Dyburiai and Ryadino our modelling supports the interpretation of glacially-induced fault reactivation, while at Slinkis, Kumečiai and Liciškėnai they likely exclude such a source. Overall, the mutual benefit of geological and modelling investigations is demonstrated. This helps in identifying glacially-induced fault reactivation at the south-eastern edge of the Weichselian glaciation and in improving models of glacial isostatic adjustment.

Doi https://doi.org/10.5200/baltica.2019.1.7

Raktažodžiai Glacial Isostatic Adjustment; Earthquake; Coulomb Failure Stress; Finite element modelling; Baltic countries; Soft-sediment deformation structure; Seismites

Pilnas tekstas

Santrauka New data were obtained from the sedimentary sequence study of Lieporiai palaeolake, Northern Lithuania, employing a multi-proxy abiotic approach, for the description of the Lateglacial-Early Holocene palaeoenvironmental dynamics in the basin. The study reveals significant differences in sediments deposited in the Lateglacial, at the end of Lateglacial/Early Holocene and in the Late Holocene time periods. Six main environmental stages are described. After glacial retreat, the formed landscape was re-organized by very fast currents that might have appeared later than previously thought. Rapid water flow stabilized and lacustrine sedimentation began together with the appearance of scarce pioneer vegetation shortly before 14 600 cal yr BP, (GI-1e). The development of the lake with mostly undisturbed sedimentation continued up to the final stages of the Lateglacial Interstadial. The warm period caused maximum precipitation of Ca and Sr carbonates, which strongly affected sediment saturation with other components. Increase in humidity in the later Lateglacial Stadial (GS-1) period is indicated by the abrupt appearance of the coarser-sized mineral matter accompanied by weathering elements, i.e. Ti, Al, Si, Mg, and the early immigration of Picea. About 11 500 cal yr BP, the mineral matter input started decreasing, and stabilization of the climate regime began about 10 200 cal yr BP. (A)biotic proxies highlight slow sedimentation mechanisms that recover shallow- and trophic-lake stages. The Lieporiai palaeolake record clearly shows the sedimentation hiatus between the Early and the Middle Holocene. Further stages are characterized by paludification processes. Finally, peat accumulation was interrupted by humans.

Doi https://doi.org/10.5200/baltica.2019.1.8

Raktažodžiai lacustrine sediments, geochemistry, SEM, abiotic data, Lateglacial, Early Holocene, NE Lithuania

Pilnas tekstas

Santrauka The large Varena Iron Ore deposit of southeast Lithuania lies beneath 200–400 m thick sedimentary cover in the East European Craton. Several drilling projects have revealed that it contains ca. 70–200 million tons of iron ore. A metasomatic origin has been proposed by several investigators, with an igneous (mafic, ultramafic carbonatitic) origin also considered. Detailed micropetrography on a variety of ore-bearing and skarnitised samples through backscattered electron imaging, along with mineral chemical analysis and monazite dating by electron microprobe, provide support for a metasomatic origin. High-grade temperature (ca. 700–750° C) skarns containing forsterite, enstatite, spinel and diopside were formed preferentially in carbonate-rich rocks and were subsequently overprinted by amphibole-bearing (tremolite, actinolite, anthophyllite and hornblende) skarns. A low-temperature hydrous influx and changing redox conditions not only caused the serpentinization of the earlier skarns, but also deposited a considerable amount of iron ore in the form of magnetite. Iron was derived from various sources and was accompanied by sulphide, apatite, REE and other mineralizations. The ca. 1.78 Ga monazite grew during the regional metamorphism, while ca. 1.54 Ga is attributed to the last mineralization phases.

Doi https://doi.org/10.5200/baltica.2019.1.9

Raktažodžiai Varena Iron Ore deposit; metasomatism; skarn; iron ore; monazite dating

Pilnas tekstas