The supplementary material is designed to provide complementary figures and plots enhancing the geochemical distribution patterns described in this research.
The ~1.62 Ga Märjamaa and Kloostri rapakivi intrusions of western Estonia record a tripartite magmatic evolution during the late stages of the Wiborg rapakivi suite, emplaced in a transtensional pull-apart setting related to shear-zone reactivation during Nuna breakup and constructed through piston cauldron-subsidence processes. Whole-rock major-element geochemistry, complemented by CIPW normative phase relations, is used to constrain melt evolution, redox conditions, and crystallization patterns across three magmatic phases. Phase I formed as a deeply rooted intrusion that evolved into a piston cauldron structure through roof collapse and block assimilation, and comprises ferroan granodioritic to quartz-monzonitic compositions with lower silica and alkalis and elevated Ca and FeâTiâP-bearing components, reflecting relatively less evolved melts. Phase II intruded as a concentric granite ring during continued subsidence and represents the most fractionated stage, characterized by higher silica and alkalis, pronounced Ca depletion, and minimal normative FeâTi oxides and apatite. Phase III corresponds to the late Kloostri body emplaced by asymmetric subsidence and represents a Na-rich leucogranitic melt with the highest silica contents and the lowest abundances of Ca-bearing, FeâTi-bearing, and P-bearing components. Progressive differ entiation from Phase I to Phase III is reflected by systematic Fe-Mg trends, whereas redox conditions are more robustly constrained by iron speciation, indicating reduced conditions in Phase II, intermediate values in Phase I, and more oxidized conditions in Phase III. Decreasing normative FeâTi oxides from Phase I to Phase III primarily reflect progressive differentiation rather than solely oxygen-fugacity variations, emphasizing the semi-quantitative nature of redox constraints derived from major-element data. Theoretical thermobarometric estimates indicate mid-crustal crystallization at ~3â5 kbar with progressive cooling from Phase I to Phase III.
This study focuses on the description and interpretation of the origin of dolocretes and their siliciclastic host rocks in the upper part of the Amata Formation (Fm) in four exposures in Latvia. The dolocretes occur in at least four intervals. The composition and structure, as well as stable oxygen and carbon isotope data of the two upper dolocrete intervals, suggest that they developed in soils. The dolocretes correspond to an episode of climate change from warm, moist to drier and hotter conditions, which started in the Late Givetian and continued to the EarlyâMiddle Frasnian. They formed during a short-lived sea-level fall, which took place after a longer sea-level rise trend. The diversity of vertebrate fossils decreases from the lower to the upper part of the Amata Fm, which is consistent with the sea-level fall and gradual climate change marked by the studied dolocretes in the upper part of the Amata Fm.
Sequence stratigraphic analysis of the NabalaâPorkuni regional stages (RSs; upper KatianâHirnantian) of Estonia clarifies the Late Ordovician evolution of the Estonian ShelfâLivonian Basin. The integration of depositional facies, biostratigraphy, carbon isotope chemostra- tigraphy, karst surfaces, and hiatuses indicates seven sequences: (1) Nabala (Paekna and Saunja Formations (Fms)); (2) Vormsi (Kõrgessaare, Tudulinna, and Fjäcka Fms); (3) Lower Pirgu (Moe and Jonstorp Fms); (4) Middle Pirgu (most of the Adila and Halliku Fms, and Jelgava and ParovÄja Fms); (5) Upper Pirgu (Kabala Member (Mb), part of the Halliku Fm); (6) Lower Porkuni Sequence (most of the Ãrina Fm); and (7) part of the Upper PorkuniâJuuru Sequence (Kamariku Mb and Saldus Fm). A lowstand systems tract is only identified in the uppermost sequence. Transgressive units are marked by onlapping depositional packages. Highstands consist of one or more shallowing-upward shelf packages (notably in the Vormsi, Lower Pirgu, and Middle Pirgu sequences). The sequences record the progradation of shallow-to-middle ramp facies as sediment infilled the northern edge of the Livonian Basin, leading to an open shelf (Porkuni RS). Eustasy was the major factor in sequence boundary formation with larger amplitude sea level oscillations associated with Hirnantian (Porkuni) glaciations. A shift to more strongly differentiated ramp facies at the NabalaâVormsi transition coincides with the initial collision of Baltica and Avalonia.
Influenced by climate warming and sea-level rise, seacoasts in many parts of the world are undergoing regime shifts, including increased coastal erosion in the southeastern Baltic Sea. The aim of this study is to reconstruct the depositional and erosional history of the Järve coastal scarp using sediment stratigraphy, new luminescence and radiocarbon dates, ground-penetrating radar, and LiDAR data. The seaward ridge, where the 3.5-m-high sandy scarp is located, began to form around 1600 years ago, in front of a 3500â4000-year-old palaeospit system that developed through sediment accumulation and postglacial uplift. The lower section of the outcrop was deposited in the shallow nearshore zone, where underwater sandbars acted as nuclei for spit formation. Darker sediment layers and variations in lamination patterns reflect changes in sediment sources and storm activity. Above the marine-deposited sandy layers lies a thin aeolian unit, which is only weakly developed at the Järve outcrop. Dune features occur only in a few blowouts, likely associated with the Little Ice Age (~1300â1850 CE) and anthropogenic vegetation disturbance, such as logging or slash-and-burn agriculture. Over the past ~100 years, the formerly emergent system of beach ridges and spits has shifted to an erosional regime. The earlier relative sea-level fall has ceased, seasonal sea ice is diminishing, the impacts of winter storms are intensifying, and the scarp is retreating. This study demonstrates how global changes are manifested on seacoasts at a local scale and highlights methodological difficulties in using seashells for coastal stratigraphic dating.
The correlation of the Silurian succession of Estonia with the global standard has long been considered reliable. However, new information, particularly on the distribution of microfossils, has changed our understanding of the Silurian stratigraphy in the region. Recent palaeontological and geochemical data suggest that: the lower part of the Juuru Regional Stage (RS) is of Hirnantian age; the age of the base of the Raikküla RS in terms of global chronostratigraphy remains problematic; the AeronianâTelychian boundary correlates with a level in the middle of the Rumba Formation (Fm); the base of the Adavere RS is of latest Aeronian age; the former Riksu Fm is considered to be the proximal, older part of the Sõrve Fm; the traditional lower boundary of the Jaagarahu RS is diachronous, and the closest biostratigraphic horizon that could be used is the first appearance datum of Jeppssonia sagitta rhenana; the WenlockâLudlow boundary correlates with a level in the upper Rootsiküla RS; the base of the Paadla RS corresponds to a level in the upper Gorstian, in the lower(?) Phlebolepis ornata Vertebrate Biozone; the Sauvere and Himmiste beds of the Paadla Fm are of late Gorstian age, and the Uduvere Beds are of early Ludfordian age, corresponding to part of the Ancoradella ploeckensis Conodont Biozone; identifying the LudlowâPÅÃdolà boundary in the Estonian succession is problematic, lacking reliable criteria at present. With these amendments, we present an updated regional correlation scheme drawn on a regular time scale for the first time. A problem that needs to be addressed in the future is providing better biostratigraphic definitions for the bases of regional stages.
This paper provides results of marine litter surveys carried out on 14 small uninhabited islands located in the coastal waters of Estonia, northeastern Baltic Sea. The islands were visited four times in total during 2019â2020. On each island, a litter survey was conducted on the beach and in terrestrial vegetation with a focus on macrolitter. Calculated over all surveys, the median value of macrolitter items per 100 m long beach section was 10.65, and the median density was 0.006 items mâ2. At the sub-basin level, the three islands located in the Gulf of Finland had the highest number of beach litter items per 100 m and the highest density (items mâ2), 38.05 and 0.017, respectively. The main litter material, representing 57.3% of all findings, was plastic; however, there were some variances across islands due to local conditions. The environmental variables most strongly correlated with differences in the composition of macrolitter were related to water movement and depth. Microlitter was found in low amounts (up to 60 items kgâ1) in the sediment of all studied islands. Litter items used as nest material were noted on all the islands with seabird colonies.
Figures S1–S4 and Tables S1 and S2 detailing the different aspects of marine litter dis tribution in the Estonian coastal sea region.
Combined sedimentological and palaeontological studies of the vertebrate fossil-bearing deposits of the Upper Devonian, Upper Famennian Ketleri Formation have provided new data on the sedimentary environment of the deposits, as well as on taxonomic and taphonomic peculiarities of the fossil assemblage. Data from numerical modelling of the Baltic Devonian Basin demonstrate that the sandy deposits of the PavÄri and Varkaļi members form a fan-shaped area resembling a wide delta developed in shallow-marine settings. Fluvial channels and bars with strong tidal influence were identified in a sedimentological study of the PavÄri site, suggesting a tide-influenced fluvial environment. Taphonomic studies indicate that the sedimentary concentrations of well-preserved vertebrate remains were formed under the influence of fluvial and strong tidal processes in a shallow-water environment, most likely in tide-influenced deltaic settings. Trace fossils recognised in the Ketleri and PavÄri-1 sites suggest a brackish-water or marine environment, and thus support the hypothesis. The analysis of rhizocretes from the Varkaļi Member suggests the strong influence of a seasonal climate. Well-preserved plant macroremains have been discovered for the first time during this study in the Ketleri Formation.
The Katian Age, part of the Late Ordovician Epoch, was a period of significant stromatoporoid diversification. However, their fossil record is often less continuous, hindering our understanding of their diversity and diversification. Estonia, which was part of Baltica during the Ordovician, is one of the most intensively studied areas for stromatoporoids. In this study, we describe a new species of the stromatoporoid genus Rosenella, named R. hosholmia sp. nov., from the Upper Ordovician Pirgu Stage Adila Formation (late Katian in age) of Estonia. The specimens were collected from the Hosholm locality on Vormsi Island. R. hosholmia is characterised by high variability in cyst size and an alternation of sporadic layers of denser, either smaller or larger, cyst plates. The cyst plates display short, thin, sharp denticles, appearing as tightly clustered points in tangential sections. Ichnofossils Planolites and Coprulus occur with this new Rosenella species. This discovery marks the first record of Rosenella in the Ordovician of Baltica, extending the palaeogeographic range of this genus beyond its known occurrences in Gondwana, peri-Gondwanan terranes, and the AltaiâSayan Fold Belt of southwestern Siberia during the Middle to Late Ordovician interval. The finding highlights the potential for further discoveries in well-studied areas, and suggests that stromatoporoid diversity in Baltica may be higher than previously known. The lack of stromatoporoid faunal similarity between Baltica and any other continents, including Laurentia, during the Ordovician contrasts with other organisms such as cephalopods and brachiopods, indicating asynchronous dispersal patterns across different groups.
The frequency of high floods is one of the most important factors shaping the riverbed and influencing other aspects, such as sediment transport and deposition, vegetation establishment and growth. The aim of this study is to assess the impact of climate change on the flood regime of the Neris River (eastern part of the Baltic Sea basin) and the related changes in river islands, morphometric indicators of the riverbed, and vegetation colonization. To identify changes in the hydrological regime of the river, water level measurement data from the Buivydžiai and Jonava hydrological stations were used. To assess vegetation coverage and the presence of islands in the Neris River, orthophotos at a scale of 1:10 000 from the years 2005â2006, 2012â2013, and 2018â2020 were analyzed. Using the ArcGIS ArcMap software package, river island area and island forest coverage were calculated. The results of the study show that during the observation period (2005â2020), in the lower course of the river, the area of the islands increased, and island forest coverage grew from 7% to 18%. Between 2005 and 2020, the water level in the lower course rose above 300 cm (above the stationâs zero line) only twice. The absence of high floods creates favorable conditions for plants to colonize alluvial environments. Consequently, this may lead to extreme flood events in the future, caused by a restructured river channel following a prolonged period of low flood activity.
The Värska 6 well extracts mineral water from the sandstones of the Gdov aquifer at a depth of 575â595 m, with a total dissolved solids contents varying between 17 and 27 g/L. The aim of the work was to study 1) the market for nasal/throat sprays in Estonia; 2) the opinions of pharmacy employees and customers; 3) the composition and sterility of the mineral water; and 4) the possibility of developing a nasal/throat spray based on local mineral water. A total of 17 nasal sprays were marketed in Estonia in 2022, of which 12 were for nasal use only and 5 were nasal/throat sprays. Most (70%) were solutions with isotonic salt concentrations made from dissolved or undiluted sterilised seawater or ocean water. The indications for their use are diverse, ranging from daily nasal hygiene to the relief of colds. Värska 6 water has a high salinity (20 g/L), a NaâCl chemical type, and â compared to ocean water and nasal sprays made from ocean water â is enriched in lithophile elements (Fe, Mn, Li, Sr, and Ba) characteristic of deep groundwater. The hypertonic Värska 6 mineral water is bacteriologically clean, and the temporal stability test confirmed that the mineral water does not promote bacterial growth but inhibits it. A new product was developed â the mineral water-based hypertonic nasal/throat spray Tsilk.
The vertebrate microremains from the Wenlock (lower Silurian) to the Lower Lochkovian (Lower Devonian) of the Ufa Amphitheatre, on the western slope of the Central Urals, have been studied. This investigation discusses vertebrate taxonomy and biostratigraphy, with an emphasis on the agnathan groups Thelodonti, Heterostraci, Osteostraci, and Anaspida. The thelodont species identified in the region include Paralogania martinssoni (Gross), Phlebolepis elegans Pander, Thelodus laevis (Pander), Thelodus carinatus (Pander), Thelodus parvidens Agassiz, Thelodus sculptilis Gross, Thelodus trilobatus (Hoppe), Turinia pagei (Powrie), Boreania minima KaratajÅ«tÄ-Talimaa, and Talivalia elongata (KaratajÅ«tÄ-Talimaa). Representatives of Heterostraci â Eriptychiiformes with Oniscolepis Pander, and Traquairaspidiformes with âTraquairaspisâ sp. â are briefly discussed along with recently described cyathaspidid heterostracans (Archegonaspis lindstroemi Kiaer, Archegonaspis integra (Kunth), Cyathaspis alexanderi Märss, and Cyathaspis alexanderi? Märss). Osteostracans comprise Tremataspis schmidti Rohon, Tremataspis rohoni Robertson, Thyestes? sp. ind., Procephalaspis sp. ind., Tahulaspis ordinata Märss, Afanassieva et Blom and Tahulaspis praevia Märss, Afanassieva et Blom, the latter two being assigned to a new family, Tahulaspididae fam. nov. A few birkeniid anaspids (Schidiosteus mustelensis Pander, Septentrionia mucronata? Blom, Märss et Miller, and Liivilepis curvata Blom, Märss et Miller) have also been included to bring together all Silurian and Lower Devonian agnathans of the Ufa Amphitheatre in a single publication. Vertebrate distribution data have been used to determine the age of the strata and correlate the beds with those of the East Baltic. A reversed succession of vertebrate distribution was discovered in a section on the southern bank of Mikhailovsk Pond, and the recurrence of the bonebed complex was detected in the Tabuska Hill section (right bank of the River Ufa).
Plant-based data from southern Finland were used to reconstruct late Holocene warm-season temperature variability on inter-annual to longer scales. Temperature-sensitive records representing maximum latewood density of Pinus sylvestris tree rings (since AD 760) and phenological stages of several plant species (since AD 1750) explained ~60% and ~70% of instrumentally observed temperature variance, respectively. The value of a multi-proxy approach was demonstrated by statistical models including both variables, which explained ~80% of the temperature variance. Temperatures from the CRUTEM5 and Berkeley datasets had slight variations in their correlativity with proxy data, possibly resulting from their differing spatial representativeness over the proxy sites. Temperature history inferred from maximum latewood densities extended over the past millennium and correlated with previously published data from similar proxy records in Fennoscandia and adjacent areas. These data indicate that the region cooled since the Medieval Climate Anomaly and warmed markedly since the Little Ice Age/Maunder Minimum. In the study region, the magnitude of this long-term warming was 2.1 °C and 2.8 °C, calculated between the coldest and warmest 100-year and 30-year intervals, respectively. Collectively, our results display the potential of plant-based data from low-lying and mild boreal sites to extend our understanding of preindustrial and recent climatic changes.
This research focuses on the geochemical analysis of Paleoproterozoic metasedimentary and metavolcanic units in the Alutaguse region of northern Estonia, shedding light on the geodynamic evolution during the Svecofennian orogeny in eastern Fennoscandia. The metasedimentary units consist of micaceous gneisses (+/- Grt +/- Crd +/- Sil), and the metavolcanic units include amphibolites and pyroxenic gneisses. Geochemical analyses utilized both historical and new whole-rock geochemical data. Weathering indices indicated their applicability for provenance studies and tectonic setting analyses. Metasediments are classified by their silica content: high-SiO2 (>63 wt%) metasediments resemble litharenites, implying higher maturity and felsic origins akin to the upper continental crust reference; low-SiO2 (<63 wt%) metasediments align with graywackes and shales, indicative of mafic to intermediate origins, similar to the post-Archean Australian shale, with TiO2-Ni suggesting sedimentary trends. Discriminant tectonic parameters associated these metasedimentary groups with a continental rift domain. Total alkali-silica classified the metavolcanics as subalkaline units. Geochemical ratios, such as La/Yb vs. Zr/Nb and La/Sm vs. Sm/Yb, crossing the spinel-lherzolite trend, were closest to the primitive mantle reference. The Th/Nb and Th/Zr ratios revealed asthenospheric mantle origins for the basaltic magma sources in Alutaguse. Tectonic settings derived from Y/15-La/10-Nb/8 and TiO2-10(MnO)-10(P2O5) ratios suggested a predominant oceanic arc affinity. It is proposed here that the Alutaguse structural zone developed as the back-arc of the Tallinn-Uusimaa belt(s), following the accretion of the Bergslagen microcontinent at 1.9-1.87 Ga, concluding with the closure of the paleo-Svecofennian ocean.
Latvia's peatlands play an important role in achieving the country's climate goals and preserving natural diversity. Approximately 10% of Latvia's territory is covered by peatlands, more precisely defined as peat deposits. However, outdated inventories of these peatlands hinder the development of sustainable policies for managing natural recourses. This lack of data also complicates efforts to predict the extent of fens and assess their potential contribution to climate change mitigation, such as through rewetting activities. In this study, we assessed the extent of fens in one of Latvia's largest municipalities - Ogre. After a feasibility study using GIS tools, fen peat deposits were randomly selected and surveyed in the field to determine the type, thickness, and characteristics of the peat. Among the 20 sites surveyed, only five corresponded to fen peat deposits (with a peat layer of at least 30 cm), and only one of these qualified as a fen also in terms of vegetation and moisture regime. Existing fen peat deposits are subject to intensive erosion, mineralization, and decomposition, leading to greenhouse gas emissions. The results indicate that there are significantly fewer fen peat deposits than previously assumed, and a detailed analysis of their extent, involving field inspection and verification at the national level, is needed.
The Orij & auml;rvi area within the Paleoproterozoic Uusimaa belt contains volcanic and minor sedimentary formations, providing valuable insights into the oldest Svecofennian crust in southern Finland. Previously, felsic volcanic rocks from the Orij & auml;rvi, Kisko and Toija formations have been dated at 1895 +/- 3, 1878 +/- 4 and 1878 +/- 4 Ma, respectively. In the present study, the Sorvasto sample from the southern boundary of the Kisko formation yields a zircon age of 1885 +/- 5 Ma and a titanite age of 1800 +/- 15 Ma. The zircon age falls within the interval between previously obtained age determinations and is coeval with the common Svecofennian crustal growth stage. The Kavasto sample from the western part of the area yields a zircon age of 1878 +/- 6 Ma and a titanite age of 1796 +/- 4 Ma. The zircon age corresponds to those obtained for similar rock types in the Toija and Ahdisto formations. Picritic interlayers occur within all these successions and are here interpreted as belonging to the same Toija formation. We tentatively infer that the Toija and Salittu formations, together with the overlying sedi mentary rocks, can be traced to the West Uusimaa area in the east and the Turku area in the west. The titanite ages near 1.80 Ga reflect cooling or reheating events.
We analyze the spatio-temporal dynamics of sand relocation for beach nourishment in the low-energy coastal segment north of the Port of Klaip & edot;da, eastern Baltic Sea, under mild wave conditions, with significant wave heights below 0.9 m and water level variations from -30 to 44 cm with respect to the long-term average. In summer 2022, about 180 000 m3 of sand was added approximately 120 m from the shore at water depths of 2-3.5 m to form a 750 m long underwater bar. Sand relocation is evaluated based on repeated water depth measurements along 114 cross-shore coastal profiles. Some sand was rapidly transported to greater depths, down to about 6 m, even though wave conditions were particularly mild. The predominant sand motion was directed offshore, and characteristically for the area, wave-driven sediment transport was directed to the north. The analysis confirms that even very mild wave conditions can substantially relocate large volumes of deposited sand in shallow water, both offshore and onshore, from its original location during the initial adjustment phase following nourishment.
