Proton-stimulated redistribution of Fe atoms in quartz: Experimental modeling of the space radiation effect     

S. N. Shilobreeva  L. L. Kashkarov  M. Yu. Barabanenkov  A. N. Pustovit  V. I. Zinenko  Yu. A. Agafonov 《Doklady Earth Sciences》2006,411(9):1466-1469

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Hydrothermal sulfide deposits of the Lucky Strike vent field, Mid-Atlantic Ridge     

Yu. A. Bogdanov  A. Yu. Lein  A. M. Sagalevich  A. A. Ul’yanov  S. A. Dorofeev  N. V. Ul’yanova 《Geochemistry International》2006,44(4):403-418

Several hydrothermal sulfide structures were sampled using Mir manned submersibles in the relatively shallow Lucky Strike vent field, Mid-Atlantic Ridge; the bathymetric position of these structures varies by approximately 100 m. The investigation of the chemical and mineral compositions of hydrothermal ore occurrences led to the conclusion that the initial high-temperature ore-bearing solution ascending toward the surface became unstable and experienced phase separation beneath the ocean floor. The phase separation was responsible for the bathymetric control of hydrothermal ore formation in the ocean.  相似文献   

Melt inclusions in minerals of scapolite-bearing granulite (lower crustal xenoliths from diatremes of the Pamirs)     

V. P. Chupin  D. V. Kuz&#;min  I. A. Madyukov 《Doklady Earth Sciences》2006,407(3):507-511

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The correlation of Mesozoic gold ore districts at the Sino-Korean and Aldan-Stanovoi shields     

V. I. Kazansky  V. M. Yanovsky 《Geology of Ore Deposits》2006,48(1):43-60

The geological structure and gold ore potential of the activized Aldan-Stanovoi and Sino-Korean shields of East Asia are compared. These two regions show similar tendencies in their geological evolution during the Archean, Proterozoic, and Phanerozoic epochs but differ in types of tectonic structure and associations of ore deposits. According to recent studies by Russian and Chinese geologists, the Mesozoic complexes of these shields possess higher gold ore potential than was suggested before. As a result of these studies, the amount of conditions favoring the formation of large gold districts and deposits in the activized shields has strongly increased. Some of these deposits are polychronic and polygenetic (the Bam deposit), others are associated with J-K alkaline magmatism (the Central Aldan district), a third group of deposits are related to granites of the same age (the East Shandong district), and a fourth group includes stratiform deposits in the lower part of the udokan series (Ugui district). The various Mesozoic hydrothermal ore deposits of the northern framework of the Sino-Korean Shield are especially interesting. The study of problems of gold metallogeny was initiated in Russian geological science by Yu.A. Bilibin (1935–1940) in the central part of the Aldan Shield. Some new data concerning the gold ore potential of the Sino-Korean Shield extend our knowledge of gold ore districts in East Asia and make clear the necessity of more careful and systematic study of the gold ore potential of the Aldan-Stanovoi Shield.  相似文献   

Petrogenesis of autoliths from kimberlitic breccias in the V. Grib Pipe (Arkhangelsk district)     

Yu. Yu. Golubeva  V. A. Pervov  V. A. Kononova 《Doklady Earth Sciences》2006,411(8):1257-1262

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Petrogenesis of gold-bearing Dioritoids of the Ketkap-Yuna magmatic province, Aldan Shield     

V. F. Polin  A. I. Khanchuk  S. I. Dril  G. P. Sandimirova  L. S. Tsurikova 《Doklady Earth Sciences》2006,409(5):824-830

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Application of high-order spectra and coherence for analyzing nonlinearity of a ground response     

O. V. Pavlenko 《Doklady Earth Sciences》2006,411(8):1289-1292

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Late Mesozoic collisional granitoids of the upper Amur area: New geochemical data     

V. E. Strikha 《Geochemistry International》2006,44(8):791-807

Geochemical and isotopic data were used for a comparative analysis of Late Mesozoic (150–120 Ma) granitoids in various geological structures of the upper Amur area. The granitoids are metaluminous high-potassic I-type rocks of the magnetite series. They have variable alkalinity and consist of the monzonite-granite and granosyenite-granite associations. The monzonite-granite association consists of calc-alkaline granitoids of normal alkalinity belonging to the Umlekan-Ogodzhinskaya volcanic-plutonic zone and the Tynda-Bakaran Complex of the Stanovoy terrane. The rocks are characterized by negative anomalies of U, Ta, Nd, Hf, and Ti (in patterns normalized to the primitive mantle), with Eu anomalies pronounced weakly in the granodiorites and quartz and monzodiorites and more clearly in the granites: Eu/Eu* = 0.37–0.95, and (La/Yb)_n = 7–24, Tb_n/Yb_n = 1.4–3.2. The granosyenite-granite association comprises of moderately alkaline rocks, which are subdivided into three groups according to their geochemistry. The first group consists of phase-I granosyenites of the Uskalinskii Massif of the Umlekan-Ogodzhinskaya zone with the highest concentrations of Sc, V, Cr, Co, Ni, Cu, Cs, Rb, Sr, Y, Zr, Yb, and Th; negative anomalies at Ba, Ta, Sr, and Hf; Eu/Eu* = 0.50–0.58, (La/Yb)_n = 15–16, and Tb_n/Yb_n = 1.8. The second group comprises of moderately alkaline granitoids of the Umlekan-Ogodzhinskaya zone and the Khaiktinskii Complex of the Baikal-Vitim superterrane. Geochemically, the granitoids of this group are generally similar to the monzodiorite-granite association and differ from it in having lower concentrations of REE and Y, Eu/Eu* = 6.2–1.0, (La/Yb)_n = 28–63, and Tb_n/Yb_n = 2.1–4.5. The third group consists of granitoids of the Chubachinskii Complex of the Stanovoi terrane, which typically show negative Cs, Rb, Th, U, Ta, Hf, and Ti anomalies; the lowest concentrations of V, Cr, Co, and Ni; and the highest contents of Sr. The granosyenites of the first phase display clearly pronounced negative Eu anomalies (Eu/Eu* = 0.53–0.68), (La/Yb)_n = 7–24, and Tb_n/Yb_n = 0.8–2.0. The granitoids of the second phase have (La/Yb)_n = 51–84, no Eu anomalies, or very weak Eu anomalies (Eu/Eu* = 0.97–1.23). The silica-oversaturated leucogranites of the third phase are characterized by elevated concentrations of REE, clearly pronounced Eu anomalies (Eu/Eu* = 0.48), and flat REE patterns (Tb_n/Yb_n = 1.3). The diversity of the granitoids is demonstrated to have been caused largely by the composition of the Precambrian source, which was isotopically heterogeneous. The rocks of the monzodiorite-granite association and first-group granosyenites of the granosyenite-granite association of the Tynda-Bakaran Complex were supposedly derived from garnet-bearing biotite amphibolites. In contrast to these rocks, the source of the second-group granites of the granosyenite-granite association was of mixed amphibolite-metagraywacke composition. The third-group of granitoids were melted out of Early Proterozoic crustal feldspar-rich granulites of variable basicity, with minor amounts of Archean crustal material. The granitoids were emplaced in a collisional environment, perhaps, during the collision of the Amur superterrane and Siberian craton. This makes it possible to consider these rocks as components of a single continental volcanic-plutonic belt. Original Russian Text ? V.E. Strikha, 2006, published in Geokhimiya, 2006, No. 8, pp. 855–872.  相似文献   

Isotopic signatures of deposition and transformation of Lower Cambrian saliferous rocks in the Irkutsk amphitheater: Communication 1. Sulfur isotopic composition     

V. I. Vinogradov  G. A. Belenitskaya  M. I. Bujakaite  V. N. Kuleshov  M. A. Minaeva  B. G. Pokrovskii 《Lithology and Mineral Resources》2006,41(1):85-97

New isotope data on Lower Cambrian rocks of the Irkutsk amphitheater are reported in three communications. The first communication is devoted to the sulfur isotopic composition, which is most sensitive to ostsedimentary geochemical transformations of sulfate rocks in saliferous formations. It is shown that δ³⁴S values in Bel’sk and Zhigalovo boreholes are within 22–35‰ The lowest values are close to the sulfur isotopic composition of a halogenic basin, while the highest values are related to epigenetic sulfate reduction. This process was responsible for the elimination of 100 m of anhydrites from the Lower Cambrian section.  相似文献   

Electromagnetic methods to characterize the Savoia di Lucania waste dump (Southern Italy)     

M. Bavusi  E. Rizzo  V. Lapenna 《Environmental Geology》2006,51(2):301-308

The aim of this work is the joint application and integration of non-invasive geoelectrical methods for studying the landfill of Savoia di Lucania (Southern Italy). This landfill for its engineering features and small dimensions (70 m × 30 m × 6 m) represents an optimal test site to assess a geophysical survey protocol for municipal solid waste landfills investigation and monitoring. The landfill of Savoia di Lucania has been built with a reinforced concrete material and coated with a high-density polyethylene (HDPE) liner. Three electrical resistivity tomographies (ERT), two self-potential (SP) map surveys and one induced polarization (IP) section have been performed, both in the surrounding area and inside the waste landfill. The geophysical investigations have well defined some buried boundaries of the landfill basin and localized the leachate accumulation zones inside the dumpsite. Comparison of our results with other engineering and geological investigations could be the key for evaluating the integrity of the HDPE liner. Finally, the joint use of the ERT, IP and SP methods seems to be a promising tool for studying and designing new monitoring systems able to perform a time-lapse analysis of waste landfill geometry and integrity.  相似文献