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The authors deal with problems of the origin of peat in the territory of the West Siberian Lowland where Holocene processes are sufficiently widespread to be representative of this world-wide phenomenon. Here, for example, are found the most extensive peat bogs of the Earth. The authors deal with the stratigraphy of these peat bogs and the reconstruction of Holocene conditions in the West Siberian Lowland. The development of peat bogs has considerably modified landscape features since the retreat of the last glaciation, i.e., during the last 10,000 to 11,000 years. The peat bogs began to develop simultaneously in thousands of depressions after the ice cover had melted. Later they merged into vast peaty bog regions. Without any intervention by man the peat bogs will cover all of Western Siberia in the course of several thousands of years. The development of extensive peat bogs is due to an irregular advance of floods on Siberian rivers which leads to a rise in the water level on tributaries of great rivers and to a retardation of the discharge of flood waves In the conclusion the authors point to the problems of economic use of swampy regions and to questions of land reclamation that must be answered before economic use of the territory (mainly in connection with extensive oil and gas deposits in these regions) can be fully effective. 相似文献
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The geology of a disturbance in the Puchezh-Katunki region is reviewed and two recent hypotheses of origin are criticized. A meteoritic origin for the disturbance is proposed, since the structure and morphology of this region are similar to the sloping conical surface produced by an explosive meteor crater. The energy, mass, and size of the asteroid which could cause such a disturbance are estimated. It is shown that the probability of an impact of this size is finite [over geologic time]. The crater was formed between the end of the Triassic and the beginning of the Jurassic periods. 相似文献
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In the coastal ecosystems of the Black Sea, macrophytobenthos and, in particular, the association of Cystoseira crinite, C. barbata, Cladostephus verticillatus, and Corallina mediterranea, with its thick vegetative canopy(VC), is the key contributor to primary production(PP). Though the vertical structure of the canopy, formed by the algal association, is of principal importance to the PP level, this subject has been long-neglected by researchers. The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast. Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55–60 cm deep) sites of Sevastopol Bay(Crimean Peninsula). Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually, per horizontal surface unit, at each height( Z). The study shows that: 1) the VC is characterized by unimodal vertical distribution of biomass, with maximum estimate in the lower part, where the biomass increases to 85% of the total biomass; 2) a series of single-peaked curves reliably describes the unimodal distribution of the biomass; thalli of dif ferent age groups are found along the canopy pro?le; and 3) algae found in epiphytic synusia prefer inhabiting the upper part of the VC. The role of environmental factors(seawater turbulence and solar radiation) is discussed in reference to the formation of the vertical structure, made up of the associations of the brown algae Cystoseira. 相似文献
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Agayan S. M. Bogoutdinov Sh. R. Bulychev A. A. Soloviev A. A. Firsov I. A. 《Doklady Earth Sciences》2020,493(1):530-534
Doklady Earth Sciences - Existing methods for solving inverse problems, such as the regularization method, look mostly for a quasi-solution that may not be a solution to the original problem, but... 相似文献
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