Main aspects of the theory of ore-bearing weathering mantles in the 21st century

The theory of ore-bearing weathering mantles (WM) was developed at the Institute of Geological Sciences, USSR Academy of Sciences (currently the Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences) in the 1930s. I.I. Ginzburg was an originator of this theory. The extensive new data on the bauxite-, Ni-, Au-, REE-bearing and other rare-metal WM has led to the development of a general theory of exogenic ore deposits, which has been confirmed by forecasting, prospecting, and exploration of solid mineral resources. On considering the current status of the WM theory based on the results of precision research methods (XRD, IRS, EPR spectroscopy, DTA, electron microscopy, etc.), the main aspects determining its advance can be pointed out: (1) physicochemical simulation of WM formation; (2) identification and study of nanominerals in WM; (3) study of the contribution of organic matter to weathering; and (4) use of WM as indicators of climatic change in the Earth’s history. As is presently established, WM are natural chemical reactors of nanoparticles of various minerals. The progress in nanomineralogy of WM will facilitate the choice of rational methods of mining and recovery of valuable components. As has been proved by electron microscopy, fossilized microbial communities, biofilms, and cyanobacterial mats occur in almost all WM. The importance of studying mutual relations of inorganic and organic substances of WM in more detail is evident. Development of the idea of using WM as indicators of paleoclimate will provide insights into global changes in the environment and complement the results obtained by traditional paleoclimatic methods. This aspect is especially topical in connection with widely discussed problem of global climatic warming.     

Seasonal features of the appearance of aerosol scattering in the stratosphere and mesosphere of Kamchatka from the results of lidar observations in 2007–2009

The behavior of the vertical aerosol structure (profiles of the ratio of the coefficients of the backward total and molecular scattering) in the height interval 30–80 km is analyzed from the results of lidar observations in Kamchatka over the period from October 2007 through December 2009. The obtained data revealed a regular two-layer aerosol structure in this height range with the maxima of the ratio of the scattering coefficients in the upper stratosphere at heights 35–50 km and in the mesosphere at heights of 60–75 km, as well as a relation between seasonal variations in the aerosol stratification and the circumpolar vortex affecting dynamic processes in the atmosphere of midlatitudes. The procedure of including the aftereffect of the Hamamatsu-M8259-01 PEM, which influences the error in the calculation of the ratio of scattering coefficients, is described.     

Persistent Organic Pollutants in Barents Sea Bottom Sediments

Water Resources - Long-term observation data (2003–2018) of 625 stations were analyzed to determine the distribution of organochlorine pesticides (DDT, hexachlorobenzene, and...     

Active tectonics of the area of the two Kaliningrad earthquakes on September 21, 2004

Resulting from the seismotectonic study of the Sambian Peninsula based on the interpretation of remote sensing data (satellite images and digital elevation maps), lineaments have been identified. They may be interpreted as active faults and flexure-fracture zones. These active faults, which are expressed in the form of gentle linear swells or steps in the relief, have been found and studied during the carried out field works. There are many discovered paleoseismic dislocations in the studied areas of active faults: fracture displacements, marks of liquefaction (sand dykes), near-fault folds. These seismic dislocations may indicate seismic shocks of 7–8 intensity points occurring in the neighborhood of a modern Kaliningrad city in recent geological history. The identified active structures (Yantarny Fault Zone and Bakalino flexure-fracture zone) could control sources of the 2004 Kaliningrad earthquakes.     

Pollutant Accumulation Areas in Barents Sea Bottom Sediments

Oceanology - The issue of identifying pollutant accumulation areas in Barents Sea sediments was considered based on years-long research (2002–2018) conducted by PINRO. GIS technology and...     

Hydrodynamic conditions and vertical hydrogeochemical zonality of groundwater in the Western Khatanga Artesian Basin

The results of hydrogeochemical studies of oil-and-gas bearing deposits in the western Khatanga Artesian Basin are given. The hydrogeological structure that formed during a long geological time is complicated by different types of hydrogeological sections. The boundaries of their occurrence have been established for the first time and detailed hydrogeological zoning has been carried out.     

Tectonic position and geological manifestations of the 2006 olyutor earthquake in Koryakia

The results of seismotectonic study of the epicentral zone of the major earthquake in northern Kamchatka oblast are presented. Primary and secondary surface seismic dislocations were revealed. The exposed seismic source as a complex system of seismic faults up to 140 km in total length was found and mapped in detail. The system consists of three en echelon arranged NE-oriented segments about 16, 45, and 75 km long. The general strike of the fault system coincides with the orientation of the ridges in the Koryak Highland. The kinematics of the longest northeastern segment is reverse faulting of the southeastern wall combined with right-lateral strike-slip faulting. The maximum vertical and horizontal separations are 3 and 1.5 m, respectively. Vibration fractures, griffons, landslides, and rockfalls were revealed and documented as secondary seismic dislocations. The indications of paleoseismic dislocations were studied and documented as well. The age of paleoseismic events was determined with radiocarbon method from soil samples. The seismic source is confined to the boundary of the North American and Bering Sea lithospheric plates and exhibits its internal structure for a long distance. Seismic events testify to recent geological activity of the zone of interaction between the lithospheric plates. The collected data provide insights into the structure of the seismic source and its tectonic setting at the active continental margin of Asia.     

Biogenic nanomagnetite in the Lebedinskii deposit: Evidence of biochemical processes in the origin of banded iron formation of KMA

For the first time, biogenic nanomagnetite has been detected in banded iron formation of the Lebedinskii deposit of the KMA and has been demonstrated to be a primary mineral. This finding may imply a key role of metabolic processes in primary deposition of divalent iron with formation of trivalent iron minerals, the precursors of banded iron formation of the KMA.