Constraining modern day silicon cycling in Lake Baikal

Constraining the continental silicon cycle is a key requirement in attempts to understand both nutrient fluxes to the ocean and linkages between silicon and carbon cycling over different timescales. Silicon isotope data of dissolved silica (δ30SiDSi) are presented here from Lake Baikal and its catchment in central Siberia. As well as being the world's oldest and voluminous lake, Lake Baikal lies within the seventh largest drainage basin in the world and exports significant amounts of freshwater into the Arctic Ocean. Data from river waters accounting for c. 92% of annual river inflow to the lake suggest no seasonal alteration or anthropogenic impact on river δ30SiDSi composition. The absence of a change in δ30SiDSi within the Selenga Delta, through which 62% of riverine flow passes, suggest a net balance between biogenic uptake and dissolution in this system. A key feature of this study is the use of δ30SiDSi to examine seasonal and spatial variations in DSi utilisation and export across the lake. Using an open system model against deep water δ30SiDSi values from the lake, we estimate that 20-24% of DSi entering Lake Baikal is exported into the sediment record. Whilst highlighting the impact that lakes may have upon the sequestration of continental DSi, mixed layer δ30SiDSi values from 2003 and 2013 show significant spatial variability in the magnitude of spring bloom nutrient utilisation with lower rates in the north relative to south basin

Siliceous microfossil distribution in the surficial sediments of Lake Baikal

Examination of surficial sediments at 16 stations shows minor, but consistent differences in the numbers and kinds of siliceous microfossils deposited in different regions of Lake Baikal. There is a general north-south decreasing trend in total microfossil abundance on a weight basis. Endemic plankton diatom species are the most abundant component of assemblages at all stations. Chrysophyte cysts are present at all stations, but most forms are more abundant at northern stations. Non-endemic plankton diatom species are most abundant at southern stations. Small numbers of benthic diatoms and sponge spicules are found in all samples. Although low numbers are present in offshore sediments, the benthic diatom flora is very diverse. Principal components analysis confirms primary north-south abundance trends and suggests further differentiation by station location and depth.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43071/1/10933_2004_Article_BF00682594.pd

The resource base of hydrocarbons in the territory of Khanty-Mansi Autonomous Okrug – Yugra and ways of its development

The goal of the article was to analyze the mineral resource base of hydrocarbons of zones promising for the discovery of hydrocarbon deposits, located mainly on the periphery of the territory of the Khanty-Mansy Autonomous Okrug – Ugra. The second, no less important goal was to analyze the efficiency of exploration work in Ugra. Sites of subsurface resources were identified, for which an assessment of the resource base of pre-Jurassic formations and sedimentary cover was given. The most promising prospecting zones in terms of the state of reserves and resources are proposed for their inclusion in the licensing programs of the subsoil fund at the expense of all sources of funding. Information about the prospects for the preparation of «new» oil reserves through exploration drilling is given. This work is the result of the authors’ own research, including a retrospective analysis of unpublished material and available material of the V.I. Shpilman Research and Analytical Centre for the Rational Use of the Subsoil and the Department of Subsurface Management & Natural Resources of Khanty-Mansi Autonomous Okrug – Yugra geological and on this topic for the history of discovery and development of subsoil West Siberian oil and gas province