Prosperity and the New Economy in Canada’s major city regions

Canada’s three large city regions—Montréal, Toronto and Vancouver—have been relatively successful in retaining their Manufacturing bases, while at the same time adding substantial numbers of New Economy job opportunities. Deindustrialization appears to have occurred primarily in the Montréal CMA (Census Metropolitan Area) and in some smaller communities where motor vehicle manufacturing was significant. Growth in New Economy jobs has occurred in the larger CMAs; the smaller urban areas have had little success in attracting these jobs. For the most part, these trends appear to be path dependent: prosperous communities with substantial proportions of New Economy jobs are likely to remain prosperous and to attract more such jobs. The lack of significant correlation between Economic Health and the presence of immigrants, same sex couples, performing and visual artists suggests that local economic development strategies based on these factors may have limited success.     

从地球系统科学角度浅析中国地貌若干问题研究的新进展

以地球系统中各圈层的相互作用为主线,分析总结了我国沙漠地貌过程、流水地貌过程、冰川地貌过程及风沙地貌过程等领域研究的部分进展。由于我国沙漠地理位置的特殊性,其形成和演变与岩石圈构造变动即青藏高原隆升有着紧密的联系,所以,对我国沙漠形成、演变的研究能为探讨青藏高原隆升历史提供重要佐证。近30年来,有关我国沙漠形成时代的认识更新较快。新的沉积记录显示,我国西北地区的沙漠在中新世时就已经出现了,但沙漠沙丘大规模扩展可能是在中更新世才开始的。既使在晚更新世以来,我国沙漠地区的气候也有过明显波动、沙漠地貌的特征也发生过显著变化。沙漠通过为沙尘暴提供物源,对全球变化产生驱动作用。从地表过程来看,风沙地貌的形成演变不仅受风力作用,而且受流水、湖泊等多种地貌动力过程的影响,地貌类型是各种动力过程共同作用的缩影。古冰川地貌曾是最早发现的第四纪气候变化的证据。随着新的测年技术的出现,学术界对我国第四纪古冰川地貌演化过程有了较系统、全面的认识。流水地貌过程应该是地球上作用区域最广的一种地貌动力过程,对流水地貌过程的认识目前正在向微观和宏观深入。     

The magnetic fabric of some Irish Granites

Magnetic anisotropy measurements have been made on fifty-four oriented samples from the Carna and Screeb areas of the Galway Granite, and from the Ardara pluton and the Main Granite (including the Trawenagh Bay Granite) in Donegal. The origin of magnetic anisotropy in plutonic magnetic rocks is discussed, and it is concluded that it is probably due to grain alignment of inequant magnetite, which may occur either as free grains or as secondary inclusions in ferromagnesian minerals. The grain alignment may occur either whilst the magma is essentially fluid, giving a magnetic lineation transverse to the flow, or at a much later stage of consolidation during plastic deformation, in which case the magnetic lineation parallels the direction of greatest elongation. The results of the measurements are consistent with macroscopic foliations and lineations where these have been observed, but also indicate the existence of fabrics too weak to observe by conventional methods. This is because the magnetic method assesses the alignment of a very large number of grains, and is therefore much more sensitive than conventional fabric analysis. The weak fabrics can be qualitatively explained in terms consistent with other evidence relating to the emplacement of the granites, and experimental work now in progress may make possible a more quantitative interpretation.     

Towards establishing criteria for identifying trigger mechanisms for soft-sediment deformation: a case study of Late Pleistocene lacustrine sands and clays, Onikobe and Nakayamadaira Basins, northeastern Japan

Five main deformation units, discrete sheets of deformed sediments that lie between a significant thickness of undeformed sediment, were selected for study within Late Pleistocene lacustrine sands and clays in the Onikobe and Nakayamadaira Basins, northeastern Japan. The deformed units show evidence of deformation by a variety of mechanisms including fluidization, liquefaction, brittle failure and cohesive flow. Driving forces are thought to be primarily reverse density gradient systems, but also include gravitational body force, shear stress and unequal loading. The main trigger mechanisms are firstly earthquakes, secondly overloading from volcanic sands and thirdly, to a lesser extent, subaqueous currents. Consideration is given to criteria that allow the trigger mechanism to be identified. This study shows that the following criteria can be used to identify a seismic triggering agent: (i) setting; (ii) the extent of the deformation units; (iii) absence of evidence relating to other potential trigger mechanisms; and (iv) evidence relating to other potential trigger mechanisms is present but can be seen elsewhere in the stratigraphic section associated with undeformed sediment. Conversely, the following criteria, while they are important in interpreting the driving force and deformation mechanism, have no relevance to the trigger mechanism: (i) sediment composition; (ii) deformation structures being restricted to a single stratigraphic interval (<1 m thick) (not necessarily correlatable over large areas); and (iii) similarity to structures in the literature.     

青海高原冬季持续低温集中程度的气候特征及其成因

采用青海高原37个台站1961-2010年逐日气温数据, 着重讨论了持续3 d及以上低温过程集中程度的变化特征及其发生机制.结果表明: 低温集中度(LTCD)和集中期(LTCP)具有表征低温在时空场上非均匀性的较好分辨力; 近50 a青海高原冬季低温事件及其集中度均呈逐年明显减少趋势, 集中期明显提前; 利用REOF结合CAST方法分区并探讨了影响青海不同区域低温集中度的主要环流系统及因子, 发现影响柴达木盆地的主要系统为极涡和北大西洋涛动, 而青南牧区主要是由于局地气候反馈机制影响; 唐古拉地区的主要影响系统位于极区、 乌拉尔山地区及东部鄂霍次克海附近; 与东部农业区的相关体现为自西向东呈"+ - +"波列型分布, 反映冷空气不断东移过程中受东部高压阻塞, 在东部农业区堆积, 形成冷空气过程从而造成该地区集中度偏高.     

冰川前沿裸露地微生物生态学研究进展

微生物对冰川前沿裸露地土壤的发育具有影响, 并且参与生物地球化学循环, 在后续生物的定居和生长过程中起着重要作用. 近100多年来, 全球气候持续变暖, 平均温度升高了约0.74℃. 在气候变暖的影响下, 全球冰川快速退缩, 研究冰川前沿裸露地微生物的原生演替成为当前热点研究领域. 文章系统综述了冰川前沿裸露地微生物的群落结构和数量变化规律、 微生物对土壤发育和改良的作用及N循环相关微生物群落结构的变化及其作用, 旨在探索其演替规律, 为确定微生物在冰川前沿这一特殊生境中的生态功能奠定理论基础.     

Extinction chronology and palaeobiology of the cave bear (Ursus spelaeus)

The cave bear ( Ursus spelaeus ) was one of several spectacular megafaunal species that became extinct in northern Eurasia during the late Quaternary. Vast numbers of their remains have been recovered from many cave sites, almost certainly representing animals that died during winter hibernation. On the evidence of skull anatomy and low δ¹⁵N values of bone collagen, cave bears appear to have been predominantly vegetarian. The diet probably included substantial high quality herbaceous vegetation. In order to address the reasons for the extinction of the cave bear, we have constructed a chronology using only radiocarbon dates produced directly on cave bear material. The date list is largely drawn from the literature, and as far as possible the dates have been audited (screened) for reliability. We also present new dates from our own research, including results from the Urals. U. spelaeus probably disappeared from the Alps and adjacent areas – currently the only region for which there is fairly good evidence – c . 24 000 radiocarbon years BP ( c . 27 800 cal. yr BP), approximately coincident with the start of Greenland Stadial 3 ( c . 27 500 cal. yr BP). Climatic cooling and inferred decreased vegetational productivity were probably responsible for its disappearance from this region. We are investigating the possibility that cave bear survived significantly later elsewhere, for example in southern or eastern Europe.     

Some Measurements of Radon in Soils and in Stream-Water in County Durham

Radon is a radioactive gas emanating naturally from uranium rich granites and shales. It may be emitted from the ground surface into the atmosphere as a gas, or it may be dissolved into stream water and transported over distance. The levels of radon gas in soils at ground surface depend on a number of factors relating to the source of the gas and to its transmission. Igneous rocks contain the highest mean concentrations of radium and uranium. The depth of cover is relevant also. Surveys over the years by the National Radiological Protection Board (NRPB) and others have indicated that the highest concentrations in the United Kingdom occur in Cornwall, Devon and northeast Scotland. However, recent reports have indicated that high concentrations of the gas may be detected in small pockets in counties outside of those considered at high risk. This survey relates to a series of measurements taken in and around Darlington, County Durham. The results showed the presence of small areas with strong concentrations of radon in soil gas, but only minor levels of dissolved gas in stream waters.     

Counterurbanisation and the characteristics of persons migrating to West Cornwall

Studies at the macro-scale have indicated that many remote rural areas are for the first time in over a century experiencing population growth while metropolitan areas are losing population. In this paper theories of counterurbanisation directed towards explaining the redistribution of population at a national or regional scale are criticised and a more localised research framework is proposed. Such a framework is constructed for the examination of migration into West Cornwall. Results from a postal questionnaire survey of seven study areas in West Cornwall are used to illustrate differences between three population subgroups, namely, return migrants, non-return migrants and non-migrants. Clear differences emerge not only between the population subgroups but between the study areas as well. In conclusion, it is suggested that this middle-range approach should be adopted more widely in order to gain greater insight into the counterurbanisation process and to increase the prospect of relating macro-processes to local trends and human experience.     

Industrialisation in Fiji: Industrial structure and organisation

This paper analyses the significance, structure, and organisation of the manufacturing sector in Fiji, drawing on the author's earlier much larger study of industrialisation in Fiji. The latest Fijian census of industrial production (1984) and the author's 1983 survey of manufacturers in Fiji provide the main statistical basis of the study, which shows that the manufacturing sector is a moderately important component of the Fijian economy. It is dominated by resource industries, particularly food processing, but a wide range of manufacturing activities have, nonetheless, developed. There is a substantial number of small manufacturing establishments with a few large establishments, the latter, however, making an overwhelmingly important contribution to employment, gross output and value added. The market structure in the manufacturing sector is dominated by monopolies and oligopolies resulting from Fiji's small domestic market and its import substitution industrialisation strategy. There is an absence of informal sector activities in Fijian manufacturing, most firms being incorporated companies. The state has a major role as a direct producer in Fijian manufacturing. There are bound to be major changes in the manufacturing sector due to Fiji's current political crisis, but this paper does not address these because of the recency of the events and the consequent unavailability of relevant data.     

Application of hyperspectral remote sensing for environment monitoring in mining areas

Environmental problems caused by extraction of minerals have long been a focus on environmental earth sciences. Vegetation growing conditions are an indirect indicator of the environmental problem in mining areas. A growing number of studies in recent years made substantial efforts to better utilize remote sensing for dynamic monitoring of vegetation growth conditions and the environment in mining areas. In this article, airborne and satellite hypersectral remote sensing data—HyMap and Hyperion images are used in the Mount Lyell mining area in Australia and Dexing copper mining area in China, respectively. Based on the analyses of biogeochemical effect of dominant minerals, the vegetation spectrum and vegetation indices, two hyperspectral indices: vegetation inferiority index (VII) and water absorption disrelated index (WDI) are employed to monitor the environment in the mining area. Experimental results indicate that VII can effectively distinguish the stressed and unstressed vegetation growth situation in mining areas. The sensitivity of VII to the vegetation growth condition is shown to be superior to the traditional vegetation index—NDVI. The other index, WDI, is capable of informing whether the target vegetation is affected by a certain mineral. It is an important index that can effectively distinguish the hematite areas that are covered with sparse vegetation. The successful applications of VII and WDI show that hyperspectral remote sensing provides a good method to effectively monitor and evaluate the vegetation and its ecological environment in mining areas.     

Formation of quartz silt during humid tropical weathering of dune sands

Quartz dune-sand grains in northeast Australia break down in situ under humid tropical weathering conditions to form substantial amounts of silt. Fragmentation appears to occur primarily due to silica solution along microfractures and dislocation structures in grains which have experienced tectonic deformation prior to deposition. The surface textures of quartz grains viewed with the SEM exhibit a close dependency on crystallographic properties. In the B and C horizons of some weathered late Pleistocene dunes silt forms up to 10% of the bulk sediment. Local remobilisation of such deposits by wind allows selective removal of the silt which is later deposited as a thin surficial sheet in more sheltered areas downwind. These observations provide further evidence that weathering processes provide a major mechanism of silt formation and are an important factor to be considered in relation to the origin of loess and siltstones.     

Paleozoic Stratigraphy in the Qiangtang Region of Tibet: Relations of the Gondwana and Yangtze Continents and Ocean Closure Near the End of the Carboniferous

Paleozoic sequences are defined for the northern and southern Qiangtang by linking field observations in the Gaize Province to the known Paleozoic record in neighboring areas. The pre-Devonian Gemuri Group of earlier authors is divided and the use of that term is no longer recommended. The upper Paleozoic rock assemblages, geological structures, and biota of the southern Qiangtang are of Gondwana glacial aspect, but those of the northern Qiangtang show more resemblance to those of the ancient Tethys. The two assemblages are interpreted as representing, respectively, the northern margin of Gondwanaland and the southwestern margin of the Yangtze continent. The two continents are suggested to have begun to separate during the Early Carboniferous and to have rejoined in the earliest Permian. Throughout this cycle of events, the northern Qiangtang occupied a passive margin while the southern Qiangtang rocks show evidence of the development of an active margin. Basaltic rocks from the southern Qiangtang are indicative of rifting. The authors consider that the boundary separating Car-boniferous and Permian rocks of Gondwanaland and Eurasia in the Qiangtang is marked by a suture zone that extends from Lungmuco through Heitonshan, Lake Gangma, Chasang, and Dongshuanghu. This suture is linked to Lancangjiang to the east and extends on to Malaya. In the Qiangtang the suture zone is marked by evidence of substantial rifting and by dismembered ophiolites.     

The Holocene Storegga Slide tsunami in the United Kingdom

All currently known sites in the United Kingdom with evidence for the Holocene Storegga Slide tsunami are described. Information on the altitude, distribution, stratigraphical context, age, particle size profile and microfossil characteristics of the deposits is presented. The tsunami involved a greater area than previously described, reaching a coastline over 600 km long. The ubiquitous sand layer which forms the main deposit associated with the event is shown to exhibit a consistent morphology and a particle size profile marked by fining-upwards sequences. An analysis of new and previously published radiocarbon dates indicates that from evidence in the United Kingdom, the event took place sometime around 7100 radiocarbon years BP (7900 calibrated years BP). A new isobase model for mainland Scotland and adjacent areas, providing a preliminary estimate of land uplift since the tsunami, is presented. The model estimates contemporary sea surface level offshore at 14 m below the present day mean high water spring tides. Tsunami sediment run-up is greatest in inlets, where it reaches at least 25 m on Shetland and at least 5 m along the mainland coastline to the south, and run-up of the tsunami would have exceeded these values. The tsunami sediments identified here are considered particularly valuable as a synchronous marker horizon.     

Assessing the potential for significant and episodic recharge in southwestern Australia using rainfall data

Agricultural practices in semi-arid parts of southwestern Australia have increased recharge and raised groundwater levels. As a result, land salinization has occurred. Managers aim to address the problem by reducing recharge, but it is not known whether all recharge is regular and seasonal or whether a substantial component is episodic (i.e. occurs in irregular pulses). Approaches that reduce regular recharge may not be effective at reducing recharge that is episodic. Water balances were used to assess the potential for recharge to be episodic at 53 sites throughout Western Australia. The results show that, for the conditions modeled, a substantial proportion of the recharge in drier parts of the agricultural areas occurred episodically, and that direct episodic recharge could be as important in some semi-arid areas as in arid regions. Therefore, mean annual rainfall is not a strong predictor of the ratio of episodic to total recharge at a site. The model indicates that in agricultural areas, most significant and episodic recharge events occurred over just a few days in winter months, when rainfall was dominated by frontal systems. However, substantial episodic recharge also resulted from large storms during the months of January, February, and March. The implication is that it will be difficult to reduce recharge substantially, and thus control salinity, as long as agriculture relies heavily on shallow-rooted winter-growing plants. Electronic Publication     

证据权法在新疆卡拉麦里金矿带断层与金矿化空间定量评价中的应用

新疆东准噶尔卡拉麦里金矿带是新疆重要的金成矿带之一,相关学者开展了大量的生产和科研工作,取得了丰硕的找矿成果,积累了大量的研究。近年来,随着向深部探测工作的兴起和成矿预测方法的不断成熟,由定性研究向定量研究成为一种必然选择。研究在以往科研成果综合研究的基础上,建立基于ArcGis平台的数据库,应用证据权法开展卡拉麦里金矿带断层与金矿化空间定量评价研究,研究表明断层距离和断层密度为重要的证据权因子,断层距离在0~1500 m范围内,成矿作用最强,随着距离的增大,成矿作用变弱。断层密度在0.26~0.66为中高有利成矿区域。该研究成果对卡拉麦里金矿带深部及外围的找矿工作具有重要意义。     

The Behaviour of a Reinforced Soil Mattress Spanning a Cavity Modelled in a Geotechnical Centrifuge

Sinkholes can occur on land underlain by dolomite and cause substantial damage to buildings and even loss of life. More than four million people work or reside on dolomite land in South Africa and it is therefore important to be able to construct safely on dolomite land and to minimise the risk of damage to infrastructure and loss of life. Compacted soil mattresses are often used to found structures on areas underlain by dolomite. This study investigated the effect of tensile reinforcement on the behaviour of a soil mattress spanning an underlying water filled cavity designed to impose a cover subsidence sinkhole. Three small-scale models, each consisting of a soil mattress with a cover subsidence sinkhole forming underneath, were constructed and tested in a geotechnical centrifuge. In the first test, an unreinforced soil mattress was tested and in two more tests, reinforced soil mattresses with different reinforcement strengths were tested. The settlement of the unreinforced soil mattress was initially less than that of the reinforced soil mattresses up to the point at which it failed suddenly. Neither of the reinforced soil mattresses failed suddenly, but both experienced large surface settlements that would have led to substantial damage to an overhead structure.     

Numerical modeling of groundwater resource management options in the East Oweinat area,SW Egypt

Southwest Egypt is an arid area with no surface water and limited resources of useable groundwater in the well-known Nubian Sandstone Aquifer System. These groundwater reserves have been heavily exploited since the 1960s, which has led to substantial decline in the potentiometric surface of the aquifer. A calibrated regional numerical model with refined grids on the pumping centers has been used to investigate the hydrodynamic impacts of different groundwater management options on the potentiometry of the aquifers. The results indicate that there is a real danger of either dewatering the shallow aquifer in some areas (e.g., Kharga Oasis), or increasing the water depth to uneconomic lifting depth. They also indicate that, although the planned extraction rates in Dakhla, Farafra, and Bahariya oases are feasible for at least the coming 100 years, the present rate for Kharga Oasis and the planned rate for the East Oweinat area have to be reduced substantially.     

The Evolution of Wall Control Programs at Kidston Gold Mines

Concerns with crest losses have seen changes to a number of design and operating parameters to retain the integrity of the wall and the berms of the Kidston Gold Mines' Eldridge Pit. Until trials began in 1999 most final wall designs utilised large diameter blastholes up to the presplit row to achieve the wall angle. The berm crests were being lost, wall support requirements were increasing and affecting mining schedules and several fault areas were putting pit access at risk. Standard designs had been determined during the early mining years and while periodic modifications had been made there was a need for major blast pattern revision. This paper traces the development of wall control blasting programs over the years, relating designs to the geology and the evidence in the walls with the theories of the day and includes the recent trials that were conducted in what is a most unforgiving geology. Trials and improvements to ensure the walls were safe were conducted even as the mine neared its economic life. Instrumented monitoring of trials blasts has greatly increased the understanding of the damage criteria and enabled rapid revision of designs. Recent changes included reduction in presplit energy, charge redistribution and use of smaller blastholes for the trim patterns. Determination of a minimum proximity-to-final wall limit for production blastholes, establishment of the correct standoff to berm crests and walls and selective use of presplitting techniques for protecting crests have resulted in cost effectiveness, improved bench crest retention and an overall reduction in visible wall damage.     

基于GIS的证据权重法在黑龙江省西北部金矿成矿预测中的应用

在分析了黑龙江西北部地区金矿床成矿特征的基础上,建立了区域金矿找矿模型,然后提取了各类找矿信息,并在GIS中构成了与成矿有关的地层、构造、岩浆岩、遥感、物探、化探异常等11个证据图层。用证据权重模型统计综合证据图层生成研究区成矿后验概率图。按照后验概率相对大小把预测区成矿可能性划分成三级,圈定5个Ⅰ级成矿远景区,为在黑龙江省西北部进一步找矿奠定了基础。