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Izvestiya, Atmospheric and Oceanic Physics - Gravimetric data obtained by the GOCE spacecraft contributes to the development of global models of the deep structure of the Earth’s crust and...  相似文献   
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Analysis of the spatial relations of gold ore occurrences and the enclosing geological environment in the Chukotka Autonomous Okrug (ChAO) has shown that Au–quartz ore occurrences in turbidites are located predominantly in areas of the Early Cretaceous granitoid magmatism with the thick collision-type continental crust. The Cu–Au porphyry deposits are located in areas with complete development of Early Cretaceous magmatism within the outer zone of the Okhotsk–Chukchi volcanoplutonic belt (OChVB). The Au–Ag epithermal deposits are located in the areas of the Late Cretaceous granitoid magmatism within the inner and outer zones of the OChVB. The prospects of island-arc complexes for searching for Kuroku-type Au-bearing ore objects are available.  相似文献   
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New data on the abiotic conditions; species composition; abundance, distribution, and migrations of fauna; and feeding interactions in an estuary ecosystem were obtained during expeditions in the mouths of Penzhina and Talovka rivers (northwest Kamchatka). It is revealed that in the ice-free season, the hydrological regime of the estuary is determined by seasonal fluctuations of river runoff, as well as fortnightly and daily variation of tides. The estuary is characterized by hypertidal fluctuations (up to 10–12 m); strong reverse flows (up to 1.0–1.5 m/s), considerable tidal variations in salinity (from 0 to 6–9‰ at the river boundary and from 6–8 to 14–16‰ at the offshore boundary), and high water turbidity (up to 1 000 NTU or more). Based on the spatial structure of the community, three ecological zones with mobile boundaries are distinguished: freshwater (salinity 0–0.1‰), estuarine (0–12.3‰), and neritic (11.2–18.9‰). High turbidity prevents the development of phytoplankton in the estuarine zone (EZ), and the local benthic community is significantly depleted due to the desalination and wide spread of aleuritic silts. Neritic copepods and nektobenthic brackish- water crustaceans generate the maximum abundance and biomass here. The species that have adapted to the local extreme hydrologic conditions dominate and form the basis of the estuarine food chain. Dominant among the EZ vertebrates are such groups as anadromous fishes (smelts, pacific salmons, charrs, and sticklebacks); waterfowl (terns, kittiwakes, cormorants, fulmars, puffins, guillemots, auklets, and wadepipers); and predatory marine mammals (larga, ringed seal, bearded seal, and white whale). The total abundance and biomass of these animals are much higher in the pelagic EZ in comparison to neighboring zones.  相似文献   
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New data obtained using a modern analytical technique on the geochemistry and conditions of the formation of Mississippi-type ores at the Sardana deposit are presented. Comparative analysis related to other deposits of the same type was carried out. The geochemical data point to a considerable role of metamorphism of the enclosing carbonate–terrigenous masses in ore formation at the deposit.  相似文献   
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This article discusses problems of global metallogenic zonality of the Pacific Ore Belt (POB), which is understood as the complex of volcanogenic–plutonogenic units related to the evolution of the lithosphere of marginal seas; this lithosphere combines both continental and oceanic metallogenic features and also possesses a characteristic specificity of ore accumulation. It is shown that the ideas by S.S. Smirnov about the POB zonality have not considerably changed with time and, moreover, have been supported by the new global tectonic concepts. Nevertheless, the nature of metallogenic homogeneity of the external (Ag–Cu) and internal (Sn–W) zones of the POB seems to be more complicated and ambiguous. The metallogenic role of the Ag/Au ratio in ores of POB deposits is shown.  相似文献   
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Seven main ore-forming systems—porphyry and epithermal; orogenic related to granitic intrusions; magmatic ultramafic; volcanic-hosted massive sulfide and volcanic–sedimentary; sedimentary basins; related to alkaline magmatic activity; and placers and weathering mantles—are sources of high-tech critical metals. The following promising types of ore deposits containing high-tech critical metals as by-products are recognized: Cu–Mo porphyry, Fe–Cu–Au and Pb–Zn skarn, base-metal epithermal, volcanic-hosted massive sulfide, base-metal stratiform, various tin deposits, and placers containing rare metals including REE. The mineral resources of critical metals in Russia are compared with those known in other countries. The contents of high-tech critical metals in ores of some noble-metal deposits of the Russian Northeast are reported. It is shown that the subsurface of Russia possesses considerable mineral resource potential for hightech critical metals, which allows new enterprises to be created or production of operating enterprises to increase.  相似文献   
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Geology of Ore Deposits - The Valunistoe Au–Ag deposit is the third largest among epithermal deposits in Chukotka after the Kupol and Dvoinoe. It is located at the western closing of the East...  相似文献   
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Izvestiya, Atmospheric and Oceanic Physics - The results of a comparative metallogenic spatial analysis based on GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) data, which allows...  相似文献   
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Doklady Earth Sciences - Recent studies of the lithosphere based on the gravity data from the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) were used for the first time to...  相似文献   
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