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151.
152.
A. A. Sorokin A. B. Kotov V. P. Kovach V. A. Ponomarchuk V. M. Savatenkov 《Petrology》2014,22(1):65-76
Based on generalization of available geochronological data, Late Mesozoic magmatic associations in the northeastern part of the Amurian microcontinent are divided into three groups: 142–125, 124–115, and <110 Ma. The age of these associations decreases with approaching the Pacific margin of Asia. In the same direction, they show a change in sources of their parental melts: continental crust (142–125 Ma) → continental crust + PREMA (DM) (124–115 Ma) → continental crust + PREMA (DM) + EMII (<110 Ma). Isotope-geochemical (Sr-Nd) study indicates that intrusive and volcanic rocks of the Late Mesozoic magmatic associations in the northeastern part of the Amurian microcontinent were originated in geodynamic settings that provided access of enriched mantle sources to magma formation. The most probable of these settings are as follows: (1) plate sliding accompanying by the formation of slab window beneath continental margin; (2) passage of the Asian margin over the East Asian mantle hot field in the Late Mesozoic; (3) asthenospheric upwelling due to delamination of the lower crust during closure of the Mongolian-Okhotsk ocean caused by collision between the Amurian microcontinent, Dzhugdzhur-Stanovoy, and Selenga-Stanovoy superterranes in the Central Asian fold belt. 相似文献
153.
B. N. Ryzhenko 《Geochemistry International》2006,44(8):835-840
154.
Alan B Blaxland 《Lithos》1977,10(1):1-8
RbSr isotopic analyses of 10'whole-rock samples from the controversial peralkaline Norra Kärr complex of southern Sweden suggest an age (1580±62 m.y.) considerably older than had previously been anticipated, and indicate an initial 87Sr/86Sr ratio of 0.7072±0.0035 (errors at 2σ). The isotopic data are consistent with a primary magmatic origin for the Norra Kärr agpaites, but data from 8 mineral separates show that they have experienced at least one period of metamorphic disturbance since the original intrusion; the last episode of isotopic readjustment must have occurred after 1250 m.y. before present, and is attributed to the Sveconorwegian (Grenville) metamorphism. 相似文献
155.
V. Martínez-Alvarez B. Gallego-ElviraJ.F. Maestre-Valero M. Tanguy 《Estuarine, Coastal and Shelf Science》2011
A modelling approach is proposed to evaluate the environmental dynamics of coastal lagoons. The water, heat and salt balances are addressed simultaneously, providing a better estimation of evaporation and water exchanges. Compared to traditional approaches, the model presented accounts for the effects of water salinity, heat storage and net energy advected in the water body. The model was applied daily to the Mar Menor coastal lagoon (SE Spain) from 2003 through 2006. Water exchanges with the Mediterranean Sea were estimated based on the monthly trend of the lagoon salinity and were correlated with monthly averages of wind speed. The mean daily water exchange with the sea was 1.77 hm3 d−1. This exchange accounted for only 1% of the heat losses in the lagoon heat balance, and it is the most important flow in the water balance. The mean annual evaporation flux amounted to 101.3 W m−2 (3.55 mm d−1), while the sensible heat flux amounted to 19.7 W m−2, leading to an annual Bowen ratio on the order of 0.19. To validate the model, daily water temperatures were predicted based on the daily heat balance of the water body and were compared with remote sensing data from water surface standard products. 相似文献
156.
The polarity of the interplanetary magnetic field observed by the Mariner IV spacecraft is compared to the polarity of the photospheric magnetic field observed with the solar magnetograph at Mt. Wilson Observatory. Unlike the results obtained from observations during the flight of IMP-I, these polarities are not well correlated when the photospheric polarity is determined from data along a narrow latitudinal strip. It is suggested that the structure of the interplanetary field is often related to major features in the photospheric field that are observed over a broad range of solar latitudes. 相似文献
157.
W. B. Samson 《Astrophysics and Space Science》1976,44(1):217-228
Two very young star clusters, NGC 654 and IC 5146 are studied using photographic polarization measures with limiting magnitudeB=15m,with a view to determining the nature of magnetic fields in the vicinities of these clusters.Starlight from NGC 654 is found to be polarized in a direction parallel to the galactic plane, the fainter members being more strongly polarized than the brighter ones.Polarization of starlight in IC 5146 is found to be very variable in both magnitude and direction, indicating the presence of complex magnetic fields within the cluster. 相似文献
158.
A careful photometry of moustaches is carried out to reveal asymmetry of their emission in the far wings ( 1 Å), if it exists. The presence of background continuous emission in spectra of moustaches demands special care with the photometry, and makes the current method of comparison of rest-intensities inadequate. The other sources of errors are also discussed. The blue asymmetry, as a systematic difference of intensities between the blue and the red wing shows itself in some cases, being 2–3 times larger than the probable errors. In most moustaches investigated, the accompanying background continuous emission shows a rapid increase to the violet. 相似文献
159.
160.