The deglaciation history of eastern Fennoscandia - recent data from Finland

Recent stratigraphical, morphological, and radiocarbon data indicate that most of eastern Finland north of North Karelia was deglaciated in early Flandrian times between about 9500 and 9000 B.P. The Younger Dryas ice margin, represented by the Salpausselka ridges in southern Finland, continued through the North Karelian end-moraines across the eastern border of the country. In Soviet Karelia it is possibly represented by the so-called East Karelian end-moraines known from earlier studies.     

The age of mid-proterozoic phosphatic metasediments in Finland as indicated by radiometric UPb dates

Two uranium-bearing phosphatic metasedimentary occurrences at Lampinsaari, Vihanti and Temo, Nilsiä, in Finland have been dated by isotopic UPb analyses of whole rock samples to be 1876±2 Ma old. The dates reflect the time of the Svecokarelian regional metamorphism in high amphibolite facies. An analysis of a uranium thucolite from the deposit at Nuottijärvi, Paltamo, that was metamorphosed in intermediate greenschist facies gives a date of 1897±7 Ma, suggesting that the phosphatic sedimentation had occurred before that time. An upper time limit for the sedimentation is set by a previous date of 2080±45 Ma, which was obtained from a banded iron one formation. The absence of thorium in the deposits suggests a marine environment of deposition.     

ISOTOPE RECORDS FROM MONGOLIAN AND ALPINE ICE CORES AS CLIMATE INDICATORS

The link between long term changes in the isotopic composition of precipitation and surface air temperature at a given location is of exceptional importance for paleoclimatic studies, as ahs been demonstrated by many recent publications based on the isotope records from polar ice cores. By means of direct comparison with instrumental data, this paper evaluates the potential of the deuterium and oxygen-18 records from two continental glaciers for monitoring climatic trends. The isotopic data presented characterize climatically contrasted enviroments. The records from the Swiss glacier show distinct seasonal variations. Oxygen-18 is fairly well correlated with the instrumental record of atmospheric temperature; the seasonal differences in deuterium excess reflect nearness to the oceanic moisture source. By contrast, the isotope data from the Mongolian site show poor correlation with atmospheric temperature. The seasonal variations in deuterium excess, with higher values during summer time, indicate that precipitation largely originates from re-evaporated continental moisture sources. In both cases however, the correlation with temperature is significantly improved by the elimination of values derived from years where major changes in seasonal distribution and/or snow loss obviously have occurred, thereby distoring the isotopic ratios for that particular year. Depending on the site selected for study, the stable isotope composition of ice cores should therefore be viewed not only as a proxy for atmospheric temperature, but also as an additional hydrometeorological parameter and source indicator for atmospheric moisture.     

Flandrian pollen deposition rates and tree-line history in northern Fennoscandia

Previous absolute polien diagrams from northern Fennoscandia yielded evidence for a retreat of the pine limit from an earlier extended position to a position near the modern one between about 5000 and 3000 B.P. New absolute pollen data from the sediment core of Domsvatnet, a small tundra lake near the eastern coast of Varanger Peninsula, are used to demonstrate a parallel retreat in the birch limit. Areas outside the modern birch limit were colonized by early Flandrian pioneer birch woods between 9500 and 9000 B.P. and remained as birch woodland through middle Flandrian times until a retreat started around 5000 B.P. leading to the present tundra situation.
The Domsvatnet core shows anomalous high pollen deposition rates combined with relatively rapid matrix sedimentation, suggesting that pollen from outside the basin has been washed in with allochthonous material and concentrated in the sediment.     

Stream water geochemistry from selected catchments on the Kola Peninsula (NW Russia) and in neighbouring areas of Finland and Norway: 2. Time-series

Stream water composition, measured weekly for 8–9 months in 1994 in three arctic catchments on and around the Kola Peninsula (Russia, Finland and Norway), is presented in the form of time-series. In all three catchments, snowmelt causes a major dilution of the stream water, as reflected by marked dips in electrical conductance. In the most polluted catchment (C2), the snowmelt flood (the major hydrological event at these latitudes) is reflected in the stream water by a pH dip and a pulse in technogenic heavy metals (Cu, Ni, etc.), Al and S. This results from melting of the snow laden with heavy metals and sulphate, and from leaching of the topsoil layer. In the most pristine catchment (C8), snowmelt causes no heavy metal pulse (remote location) but yields an increase in stream water Al (acidic lithology/overburden). In the intermediate catchment (C5), very subdued heavy metal and S increases are noticeable in the stream water, whilst its pH increases steadily until summer (basic lithology). Some elements (Cl, S) may be mobilised out of the snowpack before its complete thawing and reach the stream 1–2 weeks ahead of the heavy metals. The substrate (soil, overburden and bedrock) of a catchment controls to a large extent its ability to buffer acid inputs.     

Stream water geochemistry from selected catchments on the Kola Peninsula (NW Russia)and in neighbouring areas of Finland and Norway: 1. Elements levels and sources

The pH, electrical conductance and concentration of six anions and 33 cations were determined in stream waters sampled in 1994 from eight arctic catchments on and adjacent to the Kola Peninsula (Russia, Finland and Norway). The catchments are located at various distances (5–300 km) from the major industrial emissions centres of Monchegorsk, Nikel and Zapoljarniy in Russia. The source of the elements can be (1) natural, marine (sea spray), (2) natural, geogenic (blowing soil/dust, till, bedrock), and/or (3) anthropogenic, industrial (emissions from smelters, dust from mining, etc.), each source showing a distinct signature. The median concentration of many contaminants can vary by up to three orders of magnitude from polluted to remote locations, and the concentration ranges observed in different catchments often do not overlap. This implies that contamination falls sharply with distance from source, but is quite profound and lasting close to the emission centres. Elevated trace metal contents in the most polluted streams indicates that deposited contaminants are transferred to the aquatic ecosystem, and eventually can reach the ocean.     

Overbank sediments from the surroundings of the Russian nickel mining and smelting industry on the Kola Peninsula

 Top and bottom samples of overbank sediments were collected at 43 sites within a 12 000 km² area around the nickel smelter in Nikel and the ore roasting plant at Zapoljarnij, in northwestern Russia. In addition, three detailed overbank profiles were sampled in 10-cm sections from three catchments representing different levels of pollution. All samples were analysed for more than 30 elements by ICP-AES following aqua regia extraction. Results obtained show that overbank sediments represent natural (geogenic) background levels rather well. Although the major pollutants (Co, Cu, Ni and S) are strongly enriched at some places close to industry, overbank sediment is not especially well suited for mapping the extent of airborne contamination in the area. Co, Cu, Ni and S are mobile within the profile collected from the most polluted catchment. Received: 23 July 1996 · Accepted 18 October 1996     

Kinematics and galactic orbits of globular clusters. I. Kinematics

The spatial velocities of 24 globular clusters have been determined. Correlations among the velocities of the clusters, their positions in the Galaxy, and their metallicity indices are investigated. The mean velocity ellipsoid is determined, which proves to be nearly spherical. Clusters belonging to different groups of blue horizontal-branch stars in accordance with Mironov, Rastorguev, and Samus’ are considered separately. Translated from Astrofizika, Vol. 43, No. 2, pp. 259-268, April–June, 2000.     

Stratification of selected hydrolytic enzyme activities in the sediment in two lakes in Finland

To investigate the stratification of hydrolytic enzyme activities and importance of subsurface layers in depolymerization of detritus biopolymers,nine hydrolytic enzyme activities involved in the cycling of carbon,phosphorus,nitrogen and sulphur were measured in various sediment layers and their extracts at Kylaniemi in Lake Saimaa in southern Finland and in Lake Ahvenjarvi in northern Finland. The results show that for each lake all nine hydrolytic enzyme activities were higher in all sediment layers than in comparable sediment extracts indicating that the major part of enzymes was bound to the sediment particles in all layers in both lakes.Carbohydratase,P-cellobiosidase,activities did not show any gradient with sediment depth at Kylaniemi in Lake Saimaa indicating that there was rapid turnover of carbohydrates in the entire sediment column.The activities of acetate esterase,butyrate esterase,phosphomonoesterase,aminopeptidase,N-acetyl glucosaminidase,sulphatase andβ-glucosidase in the deepest layers were 19-53%of those in the surface sediment indicating that depolymerization of biopolymers involved in the cycling of carbon,nitrogen,phosphorus and sulphur was substantial in subsurface sediment.