In this paper, we report new whole-rock geochemical and zircon U-Pb data for monzogranites in the NE Xing＇an block. These data constrained the petrogenesis of C type （high Sr/Y） adakitic rocks and showed the spatia...In this paper, we report new whole-rock geochemical and zircon U-Pb data for monzogranites in the NE Xing＇an block. These data constrained the petrogenesis of C type （high Sr/Y） adakitic rocks and showed the spatial extent of the influence of the Mongol-Okhostsk ocean tectonic regime and the collision between the Jiamusi Massif and Songliao Terrane. New zircon laser-ablation inductivity coupled plasma mass spectrometry （LA-ICP-MS） U-Pb data indicated that the monzogranites in the studied area were emplaced in the Early Jurassic （～ 180 Ma）. These rocks were characterized by unusally high SiO2 （≥67.49）, and Sr （461-759 ppm）, but strikingly low Y （4.63-8.06 ppm） and HREE （∑HREE = 3.83-6.49 ppm, Yb = 0.5-0.77 ppm） contents, with therefore high Sr/Y （67.2-119） and （La/Yb）N （29.7-41.5） ratios, showing the geochemical characteristics of C type adakitic granite. The data displayed negligible Eu anomalies （Eu/Eu^＊ =0.77-1.08）, LREE-enriched and pronounced negative Nb and Ta anomalies. The C-type adakites in the studied area were most likely derived from the partial melting of a thickened lower continental curst. The magma source is most likely dominated by amphibolites and garnet amphibolites. In combination with previously-reported data from igneous rocks from the Mesozoic in NE China, we conclude that the Xing＇ an block was influenced by the Mongol-Okhotsk subduction tectonic system, and experiences compressive settings from the amalgamation of the Jiamusi block in the east of the CAOB.展开更多
A considerable number of in situ permeability tests in flysch are processed to a depth of 120m with a good spatial distribution. The distribution of permeability values for the different litho-types of this formation,...A considerable number of in situ permeability tests in flysch are processed to a depth of 120m with a good spatial distribution. The distribution of permeability values for the different litho-types of this formation, their comparison and their decrease with depth is discussed. The depth where a permeability of 3 to 5×10-7m/sec can be retained (the limit of a reasonable grouting under a high dam) may be twofold if the geological history of the formation could not contain a compressional tectonic process. This depth may reach 100m in some cases. The differences in the mean values of permeability among the various litho-types are minor, while the presence of siltstones, always present although with varied participation, dramatically controls the global permeability.展开更多
Crushed fine aggregates are widely used for full or partial replacement of natural sands in concretes. The crushed sands present different characteristics from the natural sand, especially if taking into account the c...Crushed fine aggregates are widely used for full or partial replacement of natural sands in concretes. The crushed sands present different characteristics from the natural sand, especially if taking into account the content of microfine particle, the distribution of particle sizes, the shape features, besides the different lithological origin. From the rheological point of view, the crushed sands frequently provide mixtures with high yield stress, high viscosity, high cohesion and internal friction, which hinders its use in concrete. This study is focused on the evaluation of the rheological behavior of concrete mortar phase when using different lithological types of crushed sand in total replacement of natural sand. The lithological types surveyed were granite, calcitic limestone, dolomite limestone and mica schist. Each of these sand types was studied in two ways： in natura and with adjusted grading curve. The results show the best performance of calcitic limestone providing lower viscosities and lower yield stress in mortars.展开更多
基金supported by the regional geology and mineralization research program of Heilongjiang province (HLJKD201417)
文摘In this paper, we report new whole-rock geochemical and zircon U-Pb data for monzogranites in the NE Xing＇an block. These data constrained the petrogenesis of C type （high Sr/Y） adakitic rocks and showed the spatial extent of the influence of the Mongol-Okhostsk ocean tectonic regime and the collision between the Jiamusi Massif and Songliao Terrane. New zircon laser-ablation inductivity coupled plasma mass spectrometry （LA-ICP-MS） U-Pb data indicated that the monzogranites in the studied area were emplaced in the Early Jurassic （～ 180 Ma）. These rocks were characterized by unusally high SiO2 （≥67.49）, and Sr （461-759 ppm）, but strikingly low Y （4.63-8.06 ppm） and HREE （∑HREE = 3.83-6.49 ppm, Yb = 0.5-0.77 ppm） contents, with therefore high Sr/Y （67.2-119） and （La/Yb）N （29.7-41.5） ratios, showing the geochemical characteristics of C type adakitic granite. The data displayed negligible Eu anomalies （Eu/Eu^＊ =0.77-1.08）, LREE-enriched and pronounced negative Nb and Ta anomalies. The C-type adakites in the studied area were most likely derived from the partial melting of a thickened lower continental curst. The magma source is most likely dominated by amphibolites and garnet amphibolites. In combination with previously-reported data from igneous rocks from the Mesozoic in NE China, we conclude that the Xing＇ an block was influenced by the Mongol-Okhotsk subduction tectonic system, and experiences compressive settings from the amalgamation of the Jiamusi block in the east of the CAOB.
文摘A considerable number of in situ permeability tests in flysch are processed to a depth of 120m with a good spatial distribution. The distribution of permeability values for the different litho-types of this formation, their comparison and their decrease with depth is discussed. The depth where a permeability of 3 to 5×10-7m/sec can be retained (the limit of a reasonable grouting under a high dam) may be twofold if the geological history of the formation could not contain a compressional tectonic process. This depth may reach 100m in some cases. The differences in the mean values of permeability among the various litho-types are minor, while the presence of siltstones, always present although with varied participation, dramatically controls the global permeability.
文摘Crushed fine aggregates are widely used for full or partial replacement of natural sands in concretes. The crushed sands present different characteristics from the natural sand, especially if taking into account the content of microfine particle, the distribution of particle sizes, the shape features, besides the different lithological origin. From the rheological point of view, the crushed sands frequently provide mixtures with high yield stress, high viscosity, high cohesion and internal friction, which hinders its use in concrete. This study is focused on the evaluation of the rheological behavior of concrete mortar phase when using different lithological types of crushed sand in total replacement of natural sand. The lithological types surveyed were granite, calcitic limestone, dolomite limestone and mica schist. Each of these sand types was studied in two ways： in natura and with adjusted grading curve. The results show the best performance of calcitic limestone providing lower viscosities and lower yield stress in mortars.
