Alexander P. Lisitzin

Oxygen isotope composition of water and snow-ice cover of isolated lakes at various stages of separation from the White Sea

This study aimed to analyze the oxygen isotope composition of water, ice, and snow in water bodies isolated from the White Sea and to identify the structural peculiarities of these pools during the winter period. The studies were performed during early spring in Kandalaksha Bay of the White Sea, in Velikaya Salma Strait and in Rugoserskaya Inlet. The studied water bodies differ in their degree of isolation from the sea. In particular, Ermolinskaya Inlet has normal water exchange with the sea; the Lake on Zelenyi Cape represents the first stage of isolation; i. e., it has permanent water exchange with the sea by the tide. Kislo-Sladkoe Lake receives sea water from time to time. Trekhtsvetnoe Lake is totally isolated from the sea and is a typical meromictic lake. Finally, Nizhnee Ershovskoe Lake exhibits some features of a saline water body. The oxygen isotope profile of the water column in Trekhtsvetnoe Lake allows defining three layers; this lake may be called typically meromictic. The oxygen isotope profile of the water column in Kislo-Sladkoe Lake is even from the surface to the bottom. The variability of δ18O is minor in Lake on Zelenyi Cape. A surface layer (0–1 m) exists in Nizhnee Ershovskoe Lake, and the oxygen isotope variability is well pronounced. Deeper, where the freshwater dominates, the values of ?18Îvary insignificantly disregarding the water depth and temperature. This fresh water lake is not affected by the seawater and is not stratified according to the isotope profile. It is found that applying the values of ?18Î and profiles of temperature and salinity may appear as an effective method in defining the water sources feeding the water bodies isolated from the sea environment.

Geochemistry of Terricolous Lichens in the White Sea Catchment Area

This paper presents new data on the multielemental composition of terricolous lichens in the White Sea catchment area. The content of 51 chemical elements was determined in 31 samples using modern analytical methods. It was shown that the chemical composition of terricolous lichens varies widely and depends on many factors. The lithogenic dust plays the main role in accumulation of Ti, Cr, Co, Ga, Fe, Zr, Nb, Ga, Th, U, and REE. Long-range transport from remote pollution sources is important for Pb, Zn, Cd, Bi, Hg, and Se. The Kostomuksha ore dressing mill provides the local enrichment of the lichens in Fe, whereas the Monchegorsk copper-nickel enterprise affects large distances and additionally enriches the lichens in Cu, Ni, Co, Pb, and Cd in comparison with the background regions. The marine impact is reflected in elevated contents and enrichment factors in Na, Mg, and the Na/K ratio.

Multidisciplinary experiment on studying short-period variability of the sedimentary process in the northeastern part of the Black Sea

The principal aim of this work is to reveal the regularities of short-period synoptic variability of vertical flows and the composition of settling sedimentary material, to obtain information on the quantitative characteristics of the processes that influence sound-scattering layers in the water layer above the continental slope behind the shelf edge in the northeastern part of the Black Sea. The results were obtained due to improvement of the equipment and the procedures for performing sea experiments on studying physicogeological, biological, and hydrophysical processes in the upper illuminated layer of phytoplankton development.

Geochemical Features of Processes on the Ground Floor of the Marginal Filter in the River-Sea System

The interaction between ocean and continent is essentially controlled by the existence of a marginal filter in the global river-sea system, which determines the main features of the transformation of sedimentary material and individual chemical elements in the mix� ing zone of river water and seawater (1, 2). The results of longterm studies of researchers of the Laboratory of Physicogeological Investigations of the Institute of Oceanology, Russian Academy of Sciences, allowed us to reveal regularities in the evolution of this system and establish specific peculiarities of the transformation of suspended and dissolved forms of elements in the water column on the river-sea profile in the most dif� ferent areas of the World Ocean and in numerous estu� ary zones (3, 4). The main attention in these studies was given to the conditions of extraction and precipi� tation of sedimentary material to the floor from the river water in the course of its mixing with seawater, which determines successive change in the stages of the evolution of the whole system along the horizontal profile of the water column from the surface to the bottom of the estuary (1, 5). However, no less interesting and important are geochemical and hydrodynamic processes, which are developed under the bottom of the estuary, namely in the bottom deposits and the mutually related exchange system of sediment-interstitial water-bottom water, i.e., at the ground floor of the marginal filter. The point is that precipitation of particles of river suspension and colloids in the estuary zones requires months, days, and possibly even hours at relatively low depths. In the geological sense this is a momentary process. But nature provides much longer time (tens, hundreds, thousands, and tens of thousands years) for the devel� opment of early diagenesis in modern deposits.

First data on the composition of atmospheric dust responsible for yellow snow in Northern European Russia in March 2008

The descent of a large quantity of dust responsible for bright colors of atmospheric precipitation in the temperate, subpolar, and polar zones of the northern hemisphere is rarely observed [1–5]. In the twentieth century and in the beginning of the twenty-first century in the northern part of European Russia, such events had not been registered right up to March 25–26, 2008. At that time in some parts of the Arkhangelsk region, Komi Republic, and Nenets Autonomous Area, atmospheric precipitation as moist snow and rain responsible for sand and saffron colors of ice crust formation on the snow surface was observed. Thus, due to detailed mineralogical, geochemical, pollen, diatom, and meteorological investigations, it was established that the main source of the yellow dust is the semidesert and steppe regions of the Northwest Kazakhstan, and the Volgograd and Astrakhan regions, Kalmykia.

Russian-German collaboration in the arctic environmental research

The overview of the 20-years joint Russian-German multidisciplinary researches in the Arctic are represented in this article. Data were obtained during numerous marine and terrestrial expeditions, all-year-round measurements and observations. On the basis of modern research methods including satellite observation, radiocarbon (AMS 14C) dating of the Arctic sea sediments, isotope, biochemical and other methods, the new unique records were obtained. Special emphasis devoted to the latest data concerning modern sea-ice, ocean and sedimentation processes, evolution of the permafrost and paleoenvironments in the Laptev Sea System.

Cryogenic Formations of Passive Margins, Ice Shelves and Continental Slopes · Cryogenic Formations of Active Margins and the Regions Composed of Oceanic Crust

The main types of sedimentogenesis appearing under different combinations of environmental factors, composition and properties of sedimentary matter along with sedimentary rock basins, cryogenic facies and the main time relevant features of this process have been discussed above. All this establishes the main cryogenic formations based on the synthesis of all these data.

Stages of Lithogenesis in Ice Zones · Three Types of Sea Ice Sedimentation and Two Vertical Levels of the Process

The development of the notion of oceanic glacial process has been hampered by the lack of data on the processes of sediment incorporation, transportation and deposition by ice. Visual observations of ice with incorporated sedimentary material were the most important. The necessary data have been obtained only quite recently due to further progress in investigation technique and field explorations in inaccessible zones of glacial sedimentation, i.e. high latitudinal regions of the Northern and Southern Hemispheres. These investigations were supplemented by laboratory experiments. The first models have been put forward. So, processes of sedimentation in the areas covered with ice during most part of the year have become worth studied only quite recently. Understanding of these processes is based on the data obtained with the help of sputniks, research icebreakers and helicopters, drilling, study of fluxes of sedimentary material of all kinds (aerosols,cryosols andhydrosols), isotopic methods, etc.Nevertheless, this work is still far from being completed. There still remain a lot of “white spots”.

Mechanisms of Sediment Incorporation in Continental Ice-Catchment Areas

The complicated process of transformation of solid glacier bedrock into loose sediments is still far from being completely understood. At the moment three main approaches exist to solve this problem: (1) direct observations of the glacier activity (glaciohydrological investigations); (2) theoretic conclusions based on the laboratory experiments and models; (3) geomorphological investigations of both landforms appeared due to erosional activity of glaciers (fjords, troughs and other erosional forms) and accumulative landforms (different types of moraines, etc.).

Lithology and Geochemistry of the Zones of Iceberg Sedimentation

Study of the process of accumulation of marine deposits related to the various types of sea ice activity opens up new possibilities to solving the opposite problem usually arising during field investigations: how to reconstruct the origin of the beds exposed in the section or a series of sections, environmental conditions of their accumulation and their further evolution. Study of the modern processes allows solving this problem not on the basis of controversial guess-works but on the basis of comparative-lithologic method and understanding of real processes and their geologic consequences.