Manganese potential of Neogene rocks in Central Russia (Tambov-Lipetsk region)

Materials related to the manganese potential of Neogene rocks (Sosnovka Formation) in Central Russia are summarized. Concretions and geoides in primary manganese carbonates are most likely early diagenetic formations. However, we cannot also rule out the possibility of their formation after the early diagenetic (catagenetic) stage of sediment transformation. The Tambov-Lipetsk region with manganese potential outlined in this paper is located in an economically favorable setting. Probability of the discovery of commercial manganese oxide deposits in this region is discussed.     

Phase relations between Ca3Fe 2 3 +Si3O12-Fe 3 2 +Fe 2 3 +Si3O12 garnet and CaFeSi2O6-Fe2Si2O6 pyroxene solid solutions

Editorial responsibility: J. Hoefs     

基于情景的中国1951-2010年极端高温灾害的危险性分析(英文)

China is physically and socio-economically susceptible to global warming-derived high temperature extremes because of its vast area and high urban population density. This article presents a scenario-based analysis method for high temperature extremes aimed at illustrating the latter’s hazardous potential and exposure across China. Based on probability analysis, high temperature extreme scenarios with return periods of 5, 10, 20, and 50 years were designed, with a high temperature hazard index calculated by integrating two differentially-weighted extreme temperature indices (maximum temperature and high temperature days). To perform the exposure analysis, a land use map was employed to determine the spatial distribution of susceptible human activities under the different scenarios. The results indicate that there are two heat-prone regions and a sub-hotspot occupying a relatively small land area. However, the societal and economic consequences of such an environmental impact upon the North China Plain and middle/lower Yangtze River Basin would be substantial due to the concentration of human activities in these areas.     

Cytotoxic and genotoxic evaluation and chemical characterization of sewage treated using activated sludge and a floating emergent-macrophyte filter in a municipal wastewater treatment plant: a case study in Southern Brazil

This study was conducted to evaluate the chemical parameters and the cytotoxic and genotoxic potential of raw domestic sewage and effluents from treatment with activated sludge and a floating emergent-macrophyte filter from a domestic wastewater treatment plant in the city of Novo Hamburgo, Rio Grande do Sul, Brazil. The physicochemical analysis revealed that both treatment systems achieved the legal emission pattern for biochemical oxygen demand, chemical oxygen demand, and suspended solids, but ammoniacal nitrogen and E. coli values were above the limits in the macrophyte treatment effluent. Phosphorous values were above the maximum permitted for both treatments. The results obtained from the Allium cepa test and the micronuclei test in fish did not demonstrate any significant differences in both cytotoxicity (mitotic index) and genotoxicity (chromosome aberration and micronucleus) endpoints between the negative control group and the exposed groups. However, the comet assay in fish revealed a DNA damage increase in animals exposed to the 30 % concentration of the macrophyte effluent and two concentrations of the activated sludge treatment effluent (10 and 75 %), which suggests that these two treatment systems may increase wastewater genotoxicity.     

The first results of U/Pb dating and isotope geochemical studies of detrital zircons from the neoproterozoic sandstones of the Southern Timan (Djejim-Parma Hill)

This report presents the first results of U/Pb dating, isotope-geochemical, and geochemical studies of detrital zircons from the Neoproterozoic clastic rocks of the Southern Timan. Sixty-one zircon grains were treated, including 51 from red-colored sandstones and 10 grains from aleurosandstones of the Djejim Formation of the southern Chetlas-Djejim zone (Djejim-Parma Hill). It was found that the U/Pb-ages of zircons from the rocks of the Djejim Formation, varied from ∼2.97 to ∼1.20 Ga. The studies of microelement composition in 47 grains (of 61 U/Pb isotope ages obtained), on the basis of several empirical regularities found formerly, show that the detrital zircons had originated from “granites” (22 grains), “diorites” (12 grains), or their volcanic analogues, or more rarely, from “syenites” and “basites” (5 and 8 grains, respectively). The Lu/Hf isotope system of zircons allows one to estimate the model ages (T _DM^C) of the substrate magmatic rocks being parental to the zircons considered. In particular, Archean zircons are characterized by ∼2.84–3.36 Ga model ages of magmaforming rocks. For some of the grains, their model ages (∼2.84 Ga) are close to those of zircons as such (∼2.7–2.8 Ga), which points to the juvenile character of the substrate from which the parent magma of the zircons treated was fused. For Proterozoic (to Middle Riphean) zircons, the Lu/Hf isotope system allows one to estimate the model age of the substrate of their parental rocks within ∼2.00–3.36 Ga, which shows that these rocks were formed under the recycling of the Archean and Early-Proterozoic crust. The ages obtained for detrital zircons, as well as model ages of the substrate of the corresponding parental magmatic rocks, are quite comparable to the age of crystalline complexes of the ancient framework of the East European Platform (EEP), formed in the course of the Archean, Early-Proterozoic, and Early-Middle Riphean tectonomagmatic events. This permits us to conclude that the Neoproterozoic detrital complexes of the Timan were formed owing to the erosion of earlier Neoproterozoic and Early Precambrian complexes constituting the Neoproterozoic Baltica continent, presenting complexes of the passive margin of this continent. A variety of ages of detrital zircons from sandstones and aleurosandstones from the Djejim Formation of Djejim-Parma Hill, and of the estimates of magmatic rocks parental to these zircons, may be characterized as a Baltic Provenance signal.     

Stratigraphic chart of Cambrian deposits in the Turukhansk–Irkutsk–Olekma region,Siberian Platform

The former stratigraphic chart of the Cambrian in the Turukhansk–Irkutsk–Olekma region of the Siberian Platform was compiled in 1986 and approved in 1988. Large amounts of data were obtained from new wells drilled in the western and northern parts of the region during the preceding 20 years. Modifications necessitated by new data entail an indefinitely continuous series of revised facies zonation, recognition of new facies areas, regions and zone, as well as definition of a regional early Mayan stratigraphic hiatus. A new local stratigraphic division is the Olenchima Member (base of the Evenk Formation) underlain by a hiatus. The term Kochumdek Formation is no longer used in the Bakhta region and its lithologically distinct subformations (Yasenga, Moktakon, Mara, and Abakun) were raised to formation rank. The Olenchima Formation is no longer used in the Baikit zone; but instead, the Litvintsevo Formation was established here by correlation.     

Research on the Silk Road(Shaanxi Section)Heritage Constitution under the Vision of Culture Integrity

The Silk Road is one of the most important cultural routes in human being history and it had survived abundant cultural heritages.Under the vision of culture integrity,the constitution of the Silk Road(Shaanxi section)heritage corridor should involve tangible and intangible heritage elements.It is necessary to recognize the relationship between tangible and intangible culture heritages in order to realize the reasonable conservation of the Silk Road.     

Signification de la présence de radon 222 dans les fluides géothermiques

The²²²Rn content of a subterranean fluid depends on the physico-chemical nature of the media through which the fluid passes and on the time spent by the fluid in the various geological formations encountered. Consequently,²²²Rn measurement in a geofluid gives a clue to the subsurface transport conditions of this geofluid. Simple models are proposed for various types of buried structures connected with the surface by a geothermal well; they all lead to the²²²Rn concentration expressed as a function of the flow-rate of the carrier fluid. In real systems, the variations of this concentration with flow-rate would allow the type of structure feading the well to be determined, and, in propitious circumstances, the volume of the possible reservoir to be estimated.     

Moisture variability across China and Mongolia: 1951–2005

Moisture variability across China and Mongolia (hereafter, CM) during 1951–2005 was investigated using the recently developed monthly Palmer Drought Severity Index (PDSI) dataset. In total there are 206 PDSI grid points across CM, based on a 2.5° × 2.5° gridding system. For CM as a whole a significant decreasing trend in mean moisture availability was observed during 1951–2005, but with strong decadal (17.1-year) and interannual (5.0-year, 3.2-year, 2.4–2.8 year) variations. The areas affected by moderate and severe moisture deficit over CM have increased significantly since the mid-1950s. In contrast, there is a significant decreasing trend for areas affected by moderate wetness since the mid-1950s, and no significant trend was found for the areas affected by severe wetness. Ten moisture-related spatial patterns were objectively defined for CM using rotated Empirical Orthogonal Function (REOF) analysis. These patterns are related to distinct geographical areas and are associated with distinct temporal variations. Four of these patterns, in Northeast China (NE), North China (NC), Central China (CC), and East China (EC), generally demonstrate a significant decreasing trend in moisture availability. Two patterns located in western areas of Northwest China (NW) and the Tibetan Plateau (TP) show a significant moisture increase, while four patterns in Mongolia (MN), far western China (FW), South China (SC), and Southwest China (SW) do not have significant moisture trends during 1951–2005. Based on REOF results we propose that CM should be divided into ten coherent moisture divisions. Moisture variations within each division are generally coherent, but may show either similar or contrasting covariability with adjacent divisions.