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1.
Precambrian psammitic rocks of the Patom Highland as constituents of metasedimentary groups belong to the quartz-polymictic family, which is divided in each group into the following five petrochemical types: (A) highly silicic quartz sandstones, (B) silicic quartz sandstones, (C) alkali silicic quartz sandstones, (D) Fe-Si polymictic sandstones, and (E) Fe-Al-Si polymictic sandstones. The mineralogic-petrographic classification elaborated by Shutov (1967) may be applied to the calculated quantitative mineral and component compositions of metasandstone protoliths. According to this classification, the petrochemical types A–E may be correlated with monomictic (A′), oligomictic (B′), and mesomictic (C′) sandstones, feldspar-quartz graywacke (D′) and graywacke proper (E′), respectively.Quartz-polymictic sandstones make up the direct petrographic (mineralogic-petrographic) series A′-B′-C′-D′-E′ and the almost mirror inverse series E′-D′-C′-B′. The direct series A′-E′ represent the transgressive branches of sedimentary cycles that begin with the crustal redeposited products of chemical weathering, including high-Al schists and monomictic (A′) and oligomictic (B′) quartz sandstones. As the humid climate became arid, the sandstones gave way to the mesomictic sandstones C′ and to the polymictic sandstones D′ and E′ in the middle sections of sedimentary cycles. The polymictic sandstones mark culminations of tectonic activity that led to the formation of high mountains. The inverse series E′-B′ begin from the periods of mountainous topography and characterize regressive branches of sedimentary cycles that mark the decreasing tectonic activity. Polymictic sandstones E′ and D′ are replaced by oligomictic sandstones B′ in these branches. Thus, petrographic or mineralogic-petrographic series reflect the compositional evolution of psammitic rocks between epochs of peneplanation. The termination of these epochs and resumption of orogenic movements are documented by deposition of the Teptorgo-Mama, Kadalikan, and Bodaibo sedimentary groups. The onset of tectonic events fell on the terminal Paleoproterozoic, Early Riphean, and the Middle-Late Riphean. The composition of sedimentary rocks underwent progressive changes during the tectonic evolution of the continental margin of the Siberian Craton and the concomitant variation of paleoclimate. 相似文献
2.
Cessation of the Norwegian drift net fishery: changes observed in Norwegian and Russian populations of Atlantic salmon 总被引：3，自引：2，他引：1
3.
N. V. Sharov 《Izvestiya Physics of the Solid Earth》2013,49(1):34-49
On the basis of analysis and generalization of the extensive seismic information obtained over the last forty years, the modern concept of the deep crustal structure in the central Karelian Craton is developed. The tomographic models are reconstructed, the stratification of the Earth’s crust and geometry of seismic boundaries are refined, and the subsidence of the boundary between the crust and mantle down to a depth of 60 km is noted. The comparison and integrated interpretation of the sections studied by the common depth point (CDP), deep seismic sounding (DSS), and converted-wave methods together with the available geological data shows that the results derived by different seismic methods differ markedly. However, since various methods have revealed the different characteristics of the medium, the entire body of seismic evidence can be used for geological interpretation. 相似文献
4.
T. I. Moiseenko N. A. Gashkina A. N. Sharov O. I. Vandysh L. P. Kudryavtseva 《Water Resources》2009,36(3):296-309
Transformation of an Arctic aquatic ecosystem (a case study of Lake Imandra) under the impact of a mining industrial complex is considered. Water chemical composition and the ecosystem’s structural components (phyto- and zooplankton, zoobenthos, and ichthiofauna) are analyzed for the following periods: the preindustrial background (reference) conditions, industrial development of mineral resources and strong anthropogenic impact, industrial recession and decreased anthropogenic impact, and stabilization. The main regularities of the aquatic ecosystem successions under the conditions of anthropogenic loads and their decrease are established. 相似文献
5.
On the basis of 30 observations the period of the new cepheid in M31,P=75.487 is obtained. Ths cepheid has an extremely long period and gives a possibility to determine the period-amplitude envelope toward the long-period region in M31 galaxy. A comparison of the period-amplitude diagrams in various galaxies is made. 相似文献
6.
We estimate the values of the cosmological parameters using the data about peculiar velocities of 1493 flat edge-on spirals
from the RFGC catalogue. The obtained values Ω
m
= 0.21− 0.09
+ 0.22, σ8 = 1.07− 0.24
+ 0.28 differ from the WMAP values by approximately 2–3σ, but well agree with modern constraints on these parameters. Due to a strong
correlation between these quantities the shape of the 1σ, 2σ and 3σ-boundaries are rather narrow. This gives us the opportunity
to use this estimation to verify the corresponding values, obtained by different methods. 相似文献
7.
The photoelectric catalogue of the globular clusters (including the objects previously considered to be clusters) in the Andromeda Nebula M31 and its companions NGC 147, NGC185, and NGC 205 is presented. The catalogue based on all published data includes 338 objects withUBV, six objects withBV, and one object withV measurements. 相似文献
8.
9.
We present data on the six novae in the galaxy M 31 that were discovered by different groups of observers in 1998. Three of these novae were found near the nucleus of M 31, and one was found near the nucleus of M 32. 相似文献
10.
A. I. Sharov 《地理信息系统科学与遥感》2013,50(3):210-213
The author, noting the high cost and complexity of automated methods of processing imagery of the earth's cloud cover, presents a less sophisticated, instrument-aided method yielding similar results. A procedure for analyzing cloud cover patterns based on color synthesis of two-band scanner imagery from Soviet “Meteor” and American NOAA-series weather satellites using a synthesizing projector is outlined. This method adds the interpretation key of color to those of cloud structure and form in the analysis of cloud patterns, enhances cloud-underlying surface contrasts, and compares favorably with more highly automated methods in image preparation and interpretation time. Translated by Jay Mitchell; PlanEcon, Inc.; Washington, DC 20005 from: Izvestiya vysshykh uchebnykh zavedeniy, Geodeziya i aerofotos'yemka, 1987, No. 5, pp. 95-98. 相似文献