Discovery of double-peaking potassic volcanic rocks in Langshan Group of the Tanyaokou hydrothermal-sedimentary deposit,Inner Mongolia,and its indicating significance

Since the mid-1980s,Tanyaokou large Zn-Cu-Fe sulfides deposit,located at the southwest end of Langshan-Zhaertaishan-Bayan Obo Mesoproterozoic metallogenic belt in the west section of the northern margin of the North China Platform[1?9](Fig.1),has been confirmed to be submarine volcanic exhalative-sedimentary metamorphosed deposit hosted in the miogeosynclinal mud-carbonaceous formation of the Langshan Group(LG)[1],or submarine volcanic exha-lative-deposition-altered deposit[2]or stratabo…     

<Superscript>40</Superscript>Ar/<Superscript>39</Superscript>Ar chronology and geochemistry of high-K volcanic rocks in the Mangkang basin,Tibet

Our two newly obtained high-quality ⁴⁰Ar/³⁹Ar ages suggest that the high-K volcanic rocks of the Lawuxiang Formation in the Mangkang basin, Tibet were formed at 33.5 ± 0.2 Ma. The tracing of elemental and Pb-Sr-Nd isotopic geochemistry indicates that they were derived from an EM2 enriched mantle in continental subduction caused by transpression. Their evidently negative anomalies in HFSEs such as Nb and Ta make clear that there is an input of continental material into the mantle source. The high-K rocks at 33.5 ± 0.2 Ma in the Mangkang basin may temporally, spatially and compositionally compare with the early one of two-pulse high-K rocks in eastern Tibet distinguished by Wang J. H. et al., implying that they were formed in the same tectonic setting.     

Treatment of ground-motion predictive relationships for the reference seismic hazard map of Italy

In the framework of the 2004 reference seismic hazard map of Italy the amplitude of the strong-motion (expressed in terms of Peak Horizontal Acceleration with 10% probability of non-exceedence in 50 years, referred to average hard ground conditions) was computed using different predictive relationships. Equations derived in Italy and in Europe from strong-motion data, as well as a set of weak and strong-motion based empirical predictive relationships were employed in a logic tree procedure, in order to capture the epistemic uncertainty affecting ground-motion attenuation. This article describes the adjustments and conversions required to eliminate the incompatibilities amongst the relations. Particularly significant are distance conversions and style-of-faulting adjustments, as well as the problems related to the use of regional relations, such as the selection of a reference depth, the quantification of random variability and the strong-motion prediction. Moreover, a regional attenuation relationship specific for volcanic areas was also employed, allowing a more realistic evaluation of seismic hazard, as confirmed by the attenuation of macroseismic intensities.     

Volcanic risk ranking for Auckland, New Zealand. I: Methodology and hazard investigation

Volcanic eruptions typically produce a number of hazards, and many regions are at risk from more than one volcano or volcanic field. So that detailed risk assessments can be carried out, it is necessary to rank potential volcanic hazards and events in terms of risk. As it is often difficult to make accurate predictions regarding the characteristics of future eruptions, a method for ranking hazards and events has been developed that does not rely on precise values. Risk is calculated individually for each hazard from each source as the product of likelihood, extent and effect, based on the parameters order of magnitude. So that multiple events and outcomes can be considered, risk is further multiplied by the relative probability of the event occurring (probability_e) and the relative importance of the outcome (importance_o). By adding the values obtained, total risk is calculated and a ranking can be carried out.This method was used to rank volcanic hazards and events that may impact the Auckland Region, New Zealand. Auckland is at risk from the Auckland volcanic field, Okataina volcanic centre, Taupo volcano, Tuhua volcano, Tongariro volcanic centre, and Mt. Taranaki volcano. Relative probabilities were determined for each event, with the highest given to Mt. Taranaki. Hazards considered were, for local events: tephra fall, scoria fall and ballistic impacts, lava flow, base surge and associated shock waves, tsunami, volcanic gases and acid rain, earthquakes and ground deformation, mudflows and mudfills, lightning and flooding; and for distal events: tephra fall, pyroclastic flows, poisonous gases and acid rain, mudflows and mudfills, climate variations and earthquakes. Hazards from each source were assigned values for likelihood, with the largest for tephra fall from all sources, earthquakes and ground deformation, lava flows, scoria fall and base surge for an Auckland eruption on land, and earthquakes and ground deformation from an Auckland eruption in the ocean. The largest values for extent were for tephra fall and climate variation from each of the distal centres. However, these parameters do not give a true indication of risk. In a companion paper the effect of each hazard is fully investigated and the risk ranking completed.     

南海的新构造运动及其演化史

本文对南海壳块第三纪以来所发生的断裂作用、地震活动、岩浆活动与褶皱作用进行了综合研究。在此基础上,总结了南海壳块新构造运动特征并进而对其演化规律进行了探讨。     

Geochemistry of the ophiolite and oceanic island basalt in the Kangxian-Pipasi-Nanping tectonic mélange zone,South Qinling and their tectonic significance

Detailed studies indicate that Kangxian-Pipasi-Nanping tectonic zone is a complicated mélange zone which includes many tectonic slabs of different origins. Ophiolite (MORB-type basalt), oceanic island tholeiite and alkaline basalt have been identified. Moreover, this tectonic mélange zone is eastward connected with the Mianlüe suture zone. The deformation characteristics, consisting components and volcanic rock geochemical features for the Kangxian-Pipasi-Nanping tectonic mélange zone are much similar to those of the Mianlüe suture zone and Deerni ophiolite. Therefore, the Kangxian-Pipasi-Nanping tectonic mélange zone should be the westward extension part of the Mianlüe suture zone. It indicates that the Mianlüe suture zone had extended to the Nanping area.     

Macro- and meiofaunal recolonisation of dredged material used for habitat enhancement: temporal patterns in community development

In recent years, dredged material has become regarded as a potential resource and used to create and/or improve intertidal habitats (i.e., beneficial use). This paper presents the results of a sampling programme to investigate the long-term (42 months post-recharge) macro- and meiofaunal recolonisation processes of a beneficial use scheme in south-east England. While univariate indices of community structure indicated that the scheme’s meiofaunal community was never significantly different from that of a nearby reference area, such attributes for macrofauna were continually significantly below those of the reference area, although this was not the case for all reference stations. Multivariate analyses revealed that macro- and meiofaunal community structures were always significantly different from those of the reference communities. We discuss the factors responsible for these observations and propose that assessing recovery of a beneficial use scheme should be undertaken using pre-defined criteria in addition to comparisons with a reference site.     

锂离子电池硅基负极材料研究进展

硅是青海省储量丰富的资源之一,因其储锂容量高、安全性能优越,而成为锂离子电池理想的负极材料,但由于硅在深度嵌脱锂时体积效应大,易与导电介质、集流体失去电接触,造成电极循环性能迅速下降。对抑制其体积效应、增加其电导率的"低维化"和"复合化"两种技术进行了介绍。     

区域物质流通虚拟网络研究——以金沙江流域中段为例

受各种地理环境要素的制约,地形复杂区域产品、能源、生产工具等物质的流通阻力较大,建立基于阻力最小的物质流通网,对于区域发展具有重要意义。以GIS软件为分析平台,选择地形复杂的金沙江流域中段为研究对象,选取地形、地貌、植被覆盖、土地利用类型等为物质流通阻力评价指标,采用专家打分及灰色关联等评价方法,建立区域内阻力最小的物质流通虚拟网络。在该网络的基础上,分析区域内各城市的物质流通性,探讨出建立地形复杂地区最佳物质流通虚拟网络的方法。物质流通虚拟网络可为区域内道路、管道、电网的最佳线路选址提供科学依据;城市间物质流通性分析结果可为区域规划提供参考。     

基于MFA与DEA分析的辽宁省物质减量化检验研究

选择老工业基地的核心代表——辽宁省作为研究对象,分析其物质流账户指标,判断了1990～2008年辽宁省直接物质投入、生产过程排放及物质总需求3个账户指标的走向趋势;运用数据包络分析(DEA)方法分析物质流账户(MFA)主要指标的综合效率,明确了辽宁省物质减量化的急切任务,对辽宁省物质流减量化发展历程进行了检验研究。研究发现:(1)辽宁省经济增长的物质投入减量化趋势存在,物质投入对环境的破坏表现仍然比较突出。(2)辽宁省直接物质投入与生产过程排放各自的综合效率呈增长趋势,总体平均效率较低,即经济发展伴随着物质投入的相对饱和及废物排放对环境的破坏。(3)辽宁省物质减量化的反弹效应升高,表现为随直接物质投入的增加,环境压力将更加严峻;减量效应的波动变化影响了相应年份的物质投入与排放。(4)1990～2008年,辽宁省共减少直接物质投入22.88亿t、减少生产过程排放5.82亿t;潜在物质减量指数高于潜在废物减排指数,折射出由于直接物质投入的持续增长,将会导致废弃物的进一步过度排放;物质减量化总缺口与废物减排总缺口均大于0,说明辽宁省物质减量化和废物减排潜力得到一定程度实现,但是与理想状态还有较大差距。