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261.
A new version of the magnetic-tape catalog of ABELL clusters of galaxies is used to obtain redshift estimators and to generate two samples of clusters. A procedure for searching for superclusters of galaxies is applied and the results are given in tabular and graphic form. For a lmited homogeneous sample (distance 60–275 Mpc, galactic latitude B > 35°), 12 multiplets, having member clusters with known redshifts, are found. It is shown that the spatial covariance function for rich clusters has the form ξ = (r0/r)γ with r0 = 22.4 ± 1.8 Mpc and γ = 1.90 ± 0.25 for 3 Mpc ≲ r ≲ 80 Mpc. 相似文献
262.
Observations and light curves of the variable star AM Her observed in the b and v proper color system of the Abastumani two-channel photometer are presented. 相似文献
263.
M. T. Krupenin A. V. Maslov I. D. Tsybulenko R. A. Nafikov V. G. Petrishcheva 《Lithology and Mineral Resources》2000,35(3):267-277
A property of swelling on heating to yield firm lightweight granules has first been revealed for lowcarbonaceous shales (LCS)
from the Riphean stratotype in the Bashkirian Megaanticlinorium, Southern Urals. These granules possess all technological
properties of “keramzite” or claydite (an artificial, expanded clayey material) and can successfully substitute this material.
Moreover, the procedure of their manufacture, analogous to the manufacture of “shungizite” (an artificial carbonaceous-clayey
material) from Lower Proterozoic clayey rocks of Karelia, is more economical than that for keramzit. Productive beds of the
homogeneous LCS make up extended bodies tens of meters thick. At the present time, they can be used as cover rocks during
the exploitation of the Bakal siderite deposits. The LCS represent fine-grained quartz-chlorite-sericite aggregates (with
variable relationships between the major components), bearing fine-dispersed shungite in amounts of 0.5–1.0%. High-quality
raw material of this kind is characterized by a fine-dispersed admixture of a mixed-layer clayey material bearing montmorillonite
and vermiculite. Geological, lithological, mineralogical, and chemical prognostic criteria have been developed for the shungizite
raw material. It has been concluded that this construction material, new for the Urals, is promising for industrial use 相似文献
264.
J. I. S. Zonneveld 《International Journal of Earth Sciences》1955,43(2):425-426
Ohne Zusammenfassung 相似文献
265.
Ice-core samples from Upper Fremont Glacier (UFG), Wyoming, were used as proxy records for the chemical composition of atmospheric
deposition. Results of analysis of the ice-core samples for stable isotopes of nitrogen (δ15N, ) and sulfur (δ34S, ), as well as and deposition rates from the late-1940s thru the early-1990s, were used to enhance and extend existing National Atmospheric
Deposition Program/National Trends Network (NADP/NTN) data in western Wyoming. The most enriched δ34S value in the UFG ice-core samples coincided with snow deposited during the 1980 eruption of Mt. St. Helens, Washington.
The remaining δ34S values were similar to the isotopic composition of coal from southern Wyoming. The δ15N values in ice-core samples representing a similar period of snow deposition were negative, ranging from -5.9 to -3.2 ‰ and
all fall within the δ15N values expected from vehicle emissions. Ice-core nitrate and sulfate deposition data reflect the sharply increasing U.S.
emissions data from 1950 to the mid-1970s. 相似文献
266.
Lamprophyric lavas in the Colima graben,SW Mexico 总被引:2,自引:3,他引:2
The Colima graben, located in SW Mexico, is one of three grabens which intersect about 50 km SSW of Guadalajara, forming a triple junction. The 90 km long, 20–60 km wide Colima graben represents a N-S rift of the E-W trending Mexican Volcanic Belt. Since the Early Pliocene, the Colima graben has served as a locus for the eruption of alkaline lavas, the most recent of which are basanites and minettes erupted from Late Pleistocene cinder cones (Luhr and Carmichael 1981). In this paper, we report on older alkaline lavas which crop out in the graben's walls. These rocks include phlogopite- and hornblende-bearing lamprophyres, a phlogopite-kalsilite-ankaratrite, and high-K andesites. These lavas crop out throughout the Colima graben area, and are intimately associated with calc-alkaline lavas in the field. Compared to these, the alkaline rocks are strikingly enriched in the incompatible elements, particularly Ba, Sr, P, and the LREE. Unlike the younger Late Pleistocene alkaline cinder cone lavas, most of the graben wall lamprophyres and the high-K andesites represent magmas that appear to have undergone significant evolution since their generation, including fractionation, crustal contamination, and possible magma mixing. Least-squares modeling indicates that the cinder cone minettes represent reasonable parental magmas for the graben lamprophyres. The occurrence of these alkaline lavas in an active calc-alkaline volcanic arc is unusual, and we suggest that they are a manifestation of the rifting processes which produced the Colima graben. 相似文献
267.
NILANJAN DASGUPTA TARITWAN PAL JOYDEEP SEN TAMOGHNO GHOSH 《Journal of Earth System Science》2011,120(4):617-626
The study involves the characterization of pegmatoidal granite, southeast of Beawar, Ajmer district, Rajasthan. Earlier researchers
had described this granite as part of the BGC, basement to the Bhim Group of the Delhi Super Group rocks. However, the present
study indicates that it is younger than the rocks of Bhim Group of South Delhi Fold Belt, into which it is intrusive. The
intrusion is structurally controlled and the outcrop pattern is phacolithic. The granite had intruded post-D2 deformation of the Delhi orogeny along the axial planes of D2 folds. The intrusion has also resulted in the formation of a contact aureole about the calc gneisses. 相似文献
268.
269.
270.
T. A. Myskova N. M. Ivanov M. A. Korsakova R. I. Mil’kevich N. G. Berezhnaya S. L. Presnyakov 《Stratigraphy and Geological Correlation》2013,21(4):337-358
The geological, geochemical, and isotopic-geochronological data obtained for Sumian moderate-basic metavolcanites of Shombozero and Lekhta structures of the Panayarvi-Vygozero belt shows that the Tunguda Formation is confined to the Paleoproterozoic structural and material complex. This formation is represented by the complex of weakly differentiated andesitobasalts and andesites of calc-alkaline series with higher contents of MgO and moderate contents of Al2O3 and rare earth elements. The rocks of the Tunguda Formation are different from the Late Archean basic rocks of the Hiziyarvi Formation represented mainly by tholeiitic basalts with low REE contents and undifferentiated spectrum of REE distribution. The age of volcanites of the Tunguda Formation was determined to be 2439 ± 21 Ma. The xenogenic zircons from metaandesites of the Tunguda Formation have Neoarchean age according to the 207Pb/206Pb ratio (from 2536 ± 4 to 2825 ± 7 Ma). The Neoarchean zircons, a negative value of ?Nd (?3.8), and indicative geochemical parameters are evidence that the crustal component took part in formation of the protolith of the studied rocks. 相似文献