The Keiva ice marginal zone on the Kola Peninsula, northwest Russia: a key component for reconstructing the palaeoglaciology of the northeastern Fennoscandian Ice Sheet

One of the key elements in reconstructing the palaeoglaciology of the northeastern sector of the Fennoscandian Ice Sheet is the Keiva ice marginal zone (KIZ) along the southern and eastern coast of Kola Peninsula, including the Keiva I and II moraines. From detailed geomorphological mapping of the KIZ, primarily using aerial photographs and satellite images, combined with fieldwork, we observed the following. (1) The moraines display ice contact features on both the Kola side and the White Sea side along its entire length. (2) The Keiva II moraine is sloping along its length from c. 100 m a.s.l. in the west (Varzuga River) to c. 250 m a.s.l. in the east (Ponoy River). (3) The KIZ was partly overrun and fragmented by erosive White Sea-based ice after formation. From these observations we conclude that the KIZ is not a synchronous feature formed along the lateral side of a White Sea-based ice lobe. If it was, the moraines should have a reversed slope. Rather, we interpret it to be time transgressive, formed at a northeastward-migrating junction between a warm-based Fennoscandian Ice Sheet expanding from the west and southwest into the White Sea depression, and a sluggish cold-based ice mass centred over eastern Kola Peninsula. In contrast to earlier reconstructions, we find it unlikely that an ice expansion of this magnitude was a mere re-advance during the deglaciation. Instead, we propose that the KIZ was formed during a major expansion of a Fennoscandian Ice Sheet at a time pre-dating the Last Glacial Maximum.     

The results of measurements of heavy metals in atmospheric aerosols in the open areas of the Arctic Seas in 2009–2010

By experimental data on the concentration of toxic microelements (Pb, Cd, Cu, Zn, Ni, Co, and Cr) in atmospheric aerosols over the White and Norwegian Seas in winter-spring period of 2009–2010, the contamination of air environment over two sea basins, significantly different by geographical conditions but being heavily impacted by North-European industrial centres, including the impact of the largest in the European Arctic Kola industrial centre, has been analyzed. It has been indicated and described that the air basin over the White Sea water area, when compared to the Norwegian Sea, is under a significantly greater impact of the emission sources of heavy metals, located on the Kola Peninsula.     

Holocene pollen stratigraphy and bog development in the western part of the Kola Peninsula, Russia

Pollen and macrofossil investigations and radiocarbon datings were carried out at a bog in the Khibiny mountains and the northernmost bog in European Russia on the Rybachiy Peninsula (69°98'N) on the western part of the Kola Peninsula. Peat accumulation on the Kola Peninsula started at c . 8500–7500 BP. Pinus sylvestris reached its present northern limit on the peninsula by 7000 BP, while 6000–5000/4500 BP was a time of maximal progress of birch forest tundra up to the Barents Sea shoreline. Alnus ineana grew up to the Rybachiy Peninsula c . 40 km north of its present-day northern limit. By c , 5500/5300 BP Picen ohovata had immigrated to the Khibiny mountains. After 5000/4500 BP the forested area had retreated in the northern part of the Kola Peninsula and the tundra belt bordering the Barents Sea shore was formed. By 3500 BP spruce had reached its modern northern limit.     

Immigration of glacial relicts into northern Europe

On the basis of opinions held by leading Soviet geologists the author, in a paper of 1957, concluded that the immigration started from an ice-dammed lake in the valley of R. Onega, emptying into the White Sea, from which the animals had been sluiced up in front of the advancing ice-sheet. Recent geological work suggests that the Würm ice-cap of northern Europe (and adjacent Arctic regions) extended in northern Russia as far eastwards as the Urals, creating a continuous network of ice-dammed waters along the ice-front. Consequently, the relicts may have come from considerably more eastern regions than the Onega Ice Lake. The presence of relicts in lakes of the Kola Peninsula is also discussed. It is shown that these once enigmatic relict localities can be explained in the light of recent geological research, which suggests that the White Sea basin experienced a freshwater phase during the Würm deglaciation, thus allowing the relicts, which do not tolerate higher salinities, to reach even the Kola Peninsula.     

The Holocene vegetation history of the Khibiny Mountains: implications for the post‐glacial expansion of spruce and alder on the Kola Peninsula,northwestern Russia

Pollen and peat botanical investigations of the Lutnermayok peat bog, Kola Peninsula, northwestern Russia, were carried out, and 21 surface pollen samples were studied. Combined with previous studies our data form the basis for the vegetation history over the last 7000 yr of the Khibiny Mountains. Pinus sylvestris was the dominant species between 7000 and 5000 yr BP and Picea obovata penetrated to the Khibiny Mountains ca. 5500/5300 yr BP. Since 4500 yr BP, Picea replaced Pinus in major parts of the area and dominated the forest cover. Picea immigrated to the Kola Peninsula after 7000 yr BP. There were two paths of spruce migration: from the southeast and the southwest. Grey alder, Alnusincana, immigrated to the Kola Peninsula from the southwest and northwest about ca. 8000 yr BP. Grey alder has been restricted to its modern range since 4000 yr BP. The range of vertical movement of the treeline in Khibiny Mountains during the last 700 yr was 240–260 m, which corresponds to an amplitude of summer temperature change of 2°C. Copyright © 1999 John Wiley & Sons, Ltd.     

Geodynamics of the Riphean stage in the evolution of the northern passive margin of the East European Craton

The nearly parallel northwest-trending Onega-Kandalaksha, Kerets-Leshukonsky, and Barents paleorift zones located in the northeastern part of the East European Platform are interpreted as a common structural assemblage that was formed in the Middle-Late Riphean as a result of horizontal extension of the continental margin. Therefore, it is reasonable to combine these paleorift structural features into the common White Sea Rift System instead of subdividing them into two or more systems as done previously. The White Sea Rift System originated owing to the breakup of the ancient Paleopangea supercontinent 1300–1240 Ma ago. The latter event occurred as a result of the divergence of the Baltia and Laurentia continental plates that most probably was caused by mantle spreading within the hot equatorial belt of the Earth. The diffuse rifting of that time occurred in the form of near-parallel rifts developing progressively from the inner part of the continental plate toward its margin. A pericratonic sedimentary basin eventually formed at the passive margin of Baltia as a system of roughly parallel rift zones. The geologic and geophysical data show that the passive margin of the East European Platform formed in the Riphean, a phenomenon that corresponds with a model of large-scale extension of the lithosphere after the stage of early ocean-floor spreading. In the course of this process, the brittle upper crust was detached from the ductile lower crust. The geodynamic regime of the Riphean passive margin of the East European Platform probably was similar to the regime of the present-day Atlantic-type passive margins. The White Sea Rift System differs from the transverse Mid-Russian Paleorift System both in origin and age. The Mid-Russian Paleorift System is considered to have formed in the Late Riphean as a result of transtension along a mobile zone in the ancient basement. The lithosphere of northeastern Fennoscandia has experienced horizontal extension since the Middle Riphean, a phenomenon that is closely related to the evolution of the White Sea Rift System, i.e., to the formation of the passive margin of the Baltia continent.     

Pleistocene marine deposits in the coastal areas of Kola Peninsula (Russia)

On the basis of field data, datings from both electron spin resonance – and optically stimulated luminescence, and micro- and macrofauna, in addition to presence of diatoms, three Late Pleistocene marine units have been identified in the coastal areas of the Kola Peninsula. The stratigraphically lowest sequence is correlated to the Ponoi Beds and the Boreal transgression, attributed to the marine isotope stages (MIS) 5e to 5d in the White Sea depression and to MIS 5e to 5c in the Barents Sea. Thermophilic fauna and diatoms indicate normal water salinity and a water temperature above zero. The second marine unit, referred as the Strel'na Beds, can be correlated with the Early Weischselian transgression, termed the Belomorian transgression. With low water salinity and a water temperature similar or colder than the present times, Belomorian transgressions are reliably detected in the White Sea and are not clearly found in the Barents Sea. The results obtained from the sediments of the Ponoi and Strel'na Beds indicate a continuously existing marine reservoir from 130 to 80–70 ka ago (entire MIS 5) in the White Sea depression. The early Middle Weichselian Barents–Kara ice-sheet invasion and its recession might have caused the glacioeustatic Middle Weichselian (MIS 3) transgression, and the third Late Pleistocene marine sequence has been deposited in the regressing shallow cold sea with less saline waters. The results help in the understanding of the history of Late Quaternary ice sheets in North Eurasia and provide evidence for the debatable Early and Middle Weichselian marine events.     

The paleogeodynamic conditions of redeposition of conodont elements in the late devonian-early carboniferous sediments of the Southern Urals

The peculiarities of conodont fauna redeposition of the Upper Devonian-Lower Carboniferous sediments from different structural-facial zones of the Southern Urals (the Zilair megasynclinorium on the western slope of the Southern Urals (paleocontinental sector) and the Magnitogorsk-Bogdanovsk graben in the central part of the Magnitogorsk megasynclinorium on the eastern slope (paleooceanic sector)) have been studied. The regularities of conodont fauna redeposition in the flysch foredeep and riftogenous depression (of graben) formed in the back of the volcanic arc after volcanism termination have been described.     

Two Genetic Types of Pseudotachylytes

Doklady Earth Sciences - The study of two varieties of pseudotachylytes (PST) in granitoids of the Riphean complex on the Barents Sea coast of the Kola Peninsula (Rybachii and Srednii peninsulas)...     

Hydrocarbons and other volatile components in alkaline rocks from the Ukrainian shield and Kola Peninsula

Gas chromatography and other analytical techniques (EMR, PMR, and IR spectroscopy) were used to examine volatile components (CH₄, C₂-C₃, CO₂, CO, H₂, H₂O, and others) in alkaline rocks and minerals from the Ukrainian Shield (eight massifs and dikes of grorudites) and from the Khibina and Lovozero massifs in the Baltic Shield. The alkaline rocks from the Ukrainian Shield are mostly of Proterozoic (1.7–2.1 Ga) age. The alkaline rocks from the Kola Peninsula were confirmed to be rich in methane (21 ± 14 μl/g on average) and other hydrocarbons, whereas the analogous rocks from the Ukrainian Shield are poor in methane (2.1 ± 1.6 μl/g on average at a maximum of 14 μl/g). The latter rocks are richer in CO₂, which is one of the major volatile components of alkaline rocks, including agpaitic nepheline syenites from the Kola Peninsula. The rocks from the Ukrainian Shield often have elevated contents of nitrogen (up to 20 μl/g). The reasons for the differences in the composition of volatile components of rocks from the Kola Peninsula and Ukrainian Shield are as follows: the agpaitic crystallization trends of large massifs in the Kola Peninsula and much less clearly pronounced agpaitic trends in the small massifs in the Ukrainian Shield, the affiliation of these rocks with different complexes, the deeper erosion levels of the Ukrainian alkaline massifs, different ages of these rocks, etc.     

Revised tectonic implications for the magnetic anomalies of the western Weddell Sea

Ten years after the USAC (U.S.–Argentina–Chile) Project, which was the most comprehensive aeromagnetic effort in the Antarctic Peninsula and surrounding ocean basins, questions remain regarding the kinematics of the early opening history of the Weddell Sea. Key elements in this complex issue are a better resolution of the magnetic sequence in the western part of the Weddell Sea and merging the USAC data set with the other magnetic data sets in the region. For this purpose we reprocessed the USAC data set using a continuation between arbitrary surfaces and equivalent magnetic sources. The equivalent sources are located at a smooth crustal surface derived from the existing bathymetry/topography and depths estimated by magnetic inversions. The most critical area processed was the transition between the high altitude survey over the Antarctic Peninsula and the low altitude survey over the Weddell Sea that required downward continuation to equalize the distance to the magnetic source. This procedure was performed with eigenvalue analysis to stabilize the equivalent magnetic source inversion.The enhancement of the Mesozoic sequence permits refining the interpretation of the seafloor-spreading anomalies. In particular, the change in shape and wavelength of an elongated positive in the central Weddell Sea suggests that it was formed during the Cretaceous Normal Polarity Interval. The older lineations in the southwestern Weddell Sea are tentatively attributed to susceptibility contrasts modeled as fracture zones. Numerical experimentation to adjust synthetic isochrons to seafloor-spreading lineations and flow lines to fracture zones yields stage poles for the opening of the Weddell Sea since 160 Ma to anomaly 34 time. The corresponding reconstructions look reasonable within the known constraints for the motions of the Antarctic and South America plates. However, closure is not attained between 160 and 118 Ma if independent published East Antarctica–Africa–South America rotations are considered. The lack of closure may be overcome by considering relative motion between the Antarctic Peninsula and East Antarctica until 118 Ma time, an important component of convergence.     

Archean rock homologs in the Kola superdeep borehole section in the northern part of the White Sea mobile belt,Voche-Lambina test site

The Archean Complex homologs of the Kola superdeep borehole (SG-3) were identified in the northern part of the White Sea mobile belt. Tonalite-trondhjemite-granodiorite gneisses of the Voche-Lambina test site and metavolcanic dacite-rhyodacite rocks of the borehole SG-3 were formed at the stages of 2.97–2.82, ∼2.81, and 2.78–2.79 Ga. The Sm-Nd model ages of the studied rocks do not exceed 3.1 Ga, and their positive ɛNd(t) values vary from +0.5 to +3.34. They are characterized by Mg# = 0.20−0.44, similar concentrations (HFSE) of Zr, Nb, Y, and also Rb, Cr, and Ni, and sharply differentiated spectra of the REE distribution (Ce/Sm = 3.2−5.8; Gd/Yb = 2.6−7.1). Primary melts were formed in balance with garnetamphibole restite under P ≥ 15−16 kbar.     

Tectonics of the Kola collision suture and adjacent Archaean and Early Proterozoic terrains in the northeastern region of the Baltic Shield

As preparation for the deep-seismic and other geophysical experiments along the Polar Profile, which transects the Granulite belt and the Kola collision suture, structural field work has been performed in northernmost Finland and Norway, and published geological information including data from the neighbouring Soviet territory of the Kola Peninsula, have been compiled and reinterpreted.Based on these studies and a classification according to crustal and structural ages, the northeastern region of the Baltic Shield is divided into six major tectonic units. These units are separated and outlined by important low-angle, ductile shear or thrust zones of Late Archaean to Early Proterozoic age. The lateral extension of these units into Soviet territory and their involvement in large-scale crustal deformation structures, are described. Using the “view down the plunge” method, a generalised tectonic cross-section that predicts the crustal structures along the Polar Profile is compiled, and the structures around the Kola deep drill-hole are reinterpreted.The Kola suture belt, through parts of which the Kola deep bore-hole has been drilled, is considered to represent a ca. 1900 Ma old arc-continent and continent-continent collision suture. It divides the northeastern Shield region into two major crustal compartments: a Northern compartment (comprising the Murmansk and Sörvaranger units) and a Southern compartment (including the Inari unit, the Granulite belt and the Tanaelv belt, as well as the more southernly situated South Lapland-Karelia “craton” of the Karelian province of the Svecokarelian fold belt).The Kola suture belt is outlined by a 2–40 km wide and ca. 500 km long crustal belt composed of

• 1.(1) Early Proterozoic (ca. 2400-2000 Ma old) metavolcanic and metasedimentary sequences which originally formed part of the attenuated margin of the Northern Archaean compartment, and
• 2.(2) the remains of a ca. 2000-1900 Ma old, predominantly andesitic island-arc terrain.

This island-arc terrain was built up above a SW-plunging subduction zone, initiated ca. 2000 Ma ago in the southern part of a newly formed oceanic domain, the Kola ocean. Due to continued subduction and complete consumption of this ocean, the northern passive margin deposits and the island-arc terrain were brought into tectonic juxtaposition, and during the final arc-continent and continent-continent collision, they were overthrusted onto the northern Archaean continent.Along its southern boundary, the Kola suture belt is tectonically overlain by the Archaean rocks of the Inari unit. This unit was derived from a microcontinent split from the Southern compartment, the depositional basin of the protoliths of the Granulite belt being formed to the south of the microcontinent. The Inari microcontinent appears to have wedged out towards the southeast, as the continuation of the Granulite belt north of the White Sea is in direct tectonic contact with the Kola suture belt.The Granulite belt is composed of high-grade paragneisses and minor amounts of meta-igneous rocks. The paragneisses formed from thick turbidite and mass flow deposits lain down in a back-arc basin south of the Inari microcontinent. A thermal anomaly beneath the partly oceanic basement of the back-arc basin is believed to have contributed to the ca. 2000-1900 Ma old granulite facies metamorphism of the granulite assemblages. Granulite facies conditions still prevailed when the Inari microcontinent overrode the granulites and when the Granulite belt as such was formed and was overthrusted (for at least 100 km) towards the southwest. In conjunction with the latter event, the rocks of the basement of the basin also became involved in thrust movements. These now form the Tanaelv belt, which shows gradational tectonic contacts towards underlying cover and basement rocks of the South Lapland-Karelia craton. Although not all parts of this craton were affected by the Svecokarelian deformation, it is considered to belong to the Karelian province of the Svecokarelian fold belt.A ca. 1900-1800 Ma old episode of wrench faulting and the intrusion of 1790-1770 Ma old post-kinematic granites concluded the Svecokarelian evolution of the northeastern Shield region.     

The newest stage of development of the White Sea depression

Analysis of materials on the geological structure and tectonics of the White Sea depression area suggests that this depression existed in the Middle Pleistocene and was connected with the World Ocean. It is still impossible to determine the exact time of its formation due to an insufficient knowledge of the depression loose cover. However it is most likely that the depression was formed in the Late Miocene and Early Pliocene, when after the regressive development of the continental margin the shelf subsidence began. Probably in the Holocene the divergent regime was replaced by the transform regime. This period saw the subsidence of the Kandalaksha graben to about 150 m and the formation of the Kolvitsa graben. The crystalline rocks surrounding Kandalaksha bay were involved in the subsidence which is reflected in the isobase curve of the glacioisostatic uplift of the area. The combined impact of the tectonic component and the glacioisostatic uplift led to a rise of tensions which discharge caused a high seismic activity of the Kandalaksha graben and its environs.     

Postglacial emergence and the Tapes transgression, north-central Kola Peninsula, Russia

The history of postglacial emergence on the Murman coast, Kola Peninsula, is reconstructed based on twelve new radiocarbon ages from three marine sections and regional shoreline observations. Two pronounced shore levels are recognized below the Late Weichselian marine limit. The lower shoreline (11 -16 m a.s.l.) is associated with a transgression dated to 6200–6600 BP, correlative to the Tapes transgression on the Norwegian coastline. The upper shoreline (36–47 m a.s.l.) is not yet dated directly but probably correlates to the Main (Younger Dryas) shoreline. Strandline elevations descend eastward along the Murman coast. Observed emergence trends suggest the greatest regional Late Weichselian glacier load over the west-central Kola Peninsula rather than in the southern Barents Sea.     

Analysis of the mineral composition of Phanerozoic sediments of the Voronezh anteclise cover: Implication for the primary diamond potential

Origin of diamond and its indicator-minerals found in the Cretaceous, Paleogene, and Quaternary sediments in the southern sector of the East European Platform has remained a debatable issue over the past period of approximately 40 years. It was assumed that the Cretaceous diamond in the Volch’e placer and Central deposit confined to the Voronezh anteclise was derived from the Uralian sources, whereas the Paleogene diamond was derived from the South Ukrainian sources. Analysis of paleogeographic maps of new generation (scales 1: 200000–1: 500000) and new data on samples (50 samples 0.5–20 t each) examined by scientists from the Geological Research Institute of Voronezh State University with the participation of authors of the present communication support the hypothesis of local origin of diamonds and localization of their provenance in the sedimentary cover of the Voronezh anteclise. This inference pertains to high-pressure minerals detected in pre-Quaternary sediments. Diamond grains and indicator-minerals hosted in the Quaternary postglacial sediments of the Voronezh anteclise were likely derived from the Don glacial apron in the early Pleistocene (gQ_I ds) from northern areas of the platform (southeastern Finland, Karelia, Kola Peninsula, and Zimnii Bereg area of the Arkhangel’sk region). Such grains are unsuitable for prospecting purposes. Lithofacies investigations made it possible to outline two areas in the Lipetsk and Voronezh regions that likely accommodate productive diatremes.     

Geochemistry of the Kola River, northwestern Russia

The Kola River in the northern part of the Kola Peninsula, northwestern Russia, flows into the Barents Sea via the Kola Bay. The river is a unique place for reproduction of salmon and an important source of drinking water for more than 500,000 people in Murmansk and the surrounding municipalities. To evaluate the environmental status of the Kola River water, sampling of the dissolved (<0.22 μm) and suspended (>0.22 μm) phases was performed at 12 sites along the Kola River and its tributaries during 2001 and 2002. Major (Ca, K, Mg, Na, S, Si, HCO₃ and Cl) and trace (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sr, Ti, and Zn) elements, total and particulate organic C (TOC and POC), N and P were analysed. Comparison with the boreal pristine Kalix River, Northern Sweden, shows that, except for Na, Cl, Al, Cu and Ni, which exceed the concentrations in the Kalix River by as much as 2–3 times, the levels of other major and trace elements are close to or even below the levels in the Kalix River. However, the results also demonstrate that pollutants from the three major sources: (1) the Cu–Ni smelter in Monchegorsk, (2) the open-pit Fe mine and ore concentration plant in Olenegorsk, and (3) the Varlamov, the Medveziy and the Zemlanoy creeks, draining the area of the large agricultural enterprises in the lower part of the watershed, have a major influence on the water quality of the Kola River.     

Conditions of the accumulation of organic matter and metals in the bottom sediments of the Chukchi Sea

The chemical composition of bottom sediments in the Chukchi and, partly, East Siberian Seas was studied. In the south and west of the Chukchi Sea, a zone has been detected with the accumulation of sediments rich in organic carbon, an increased background content and anomalies of sulfophile metals (Mo, Zn, Hg, Ag, Au), iron-group metals (V, Ni, Co), and some PGE (Ru, Pt). This zone is confined to the neotectonic active system of rift troughs extending from the Bering Strait and eastern Chukchi Peninsula to the continental slope, where it is bounded by the Cenozoic Charlie rift basin of the Canadian hollow. The geochemical features of the carbon-enriched sediments evidence that they formed under oxygen-deficient conditions and, sometimes, in suboxic and anoxic environments near endogenic water and gas sources. The high carbon and metal contents suggest that the very fine-grained sediments in the rift troughs of the Chukchi Sea are a possible analog of some types of ancient highly carbonaceous sediments belonging to black shales.     

Late pleistocene and holocene history of the lakes in the Kola Peninsula, Karelia and the North-Western part of the East European plain

The paper reviews the work on paleolimnology in parts of the FSU over the last 40 years. It presents a short review of The History of the Lakes of the East European Plain, one of the books of the series The History of Lakes published by the Institute of Lake Research of the Russian Academy of Sciences. It describes the Late Pleistocene and Holocene history of these lakes based mainly on the study of lacustrine sediments. Amongst the samples Lake Nero near Moscow which is located near the marginal zone of the last glaciation, and includes records that go back as early as 190,000 BP. The main elements of lake evolution are shown in different territories: Byelorussia; Baltic countries; Karelia; and the Kola Peninsula. Special attention is given to palaeolimnological data because its use for Holocene and Late Pleistocene palaeoclimate reconstructions.     

Variation of chemical composition of alkaline granitic rocks in the central part of the Kola Peninsula

Chemical composition and origin of alkaline granitic rocks in the Keivy area on the Kola Peninsula were investigated. Linear correlation analysis and principal-component analysis were used to determine the interrelation of major petrogenetic elements in alkaline granite and surrounding alkaline metasomatites. Estimates of linear correlation coefficients turned out to be different, and principal-component analysis of the chemical data revealed that there were three main components influencing variation of chemical composition. These factors can be interpreted in terms of petrological processes, which are different for alkaline granite and for the surrounding metasomatites, indicating a different origin of the rocks.