Local and central state control of black settlement in Munsieville,Krugersdorp

Munsieville, one of the Witwatersrand's oldest locations, provides a valuable insight into the forms of control exercised over the urban black population for eight decades. Aspects of this control include restrictions on black movement, on the position and layout of black residential townships, and the taxing of the black population to finance the cost of their control. Resistance by the population to this control has included formal deputations to those in control, wilful contravention of restrictions and violence against symbols of their repression.     

Natural and anthropogenic sources of total suspended particulate and their contribution to the formation of black crusts on building stone materials of Catania (Sicily)

Blackening and disaggregation of exposed surfaces of stone monuments are well-known effects of stone decay taking place in polluted urban environments all over the world. This paper aims to assess the contribution of natural and anthropogenic sources of total suspended particulate (TSP) causing permanent damage (black crusts) to the stone monuments of Catania (Sicily), one of the most popular ??cities of art?? of southern Italy. Atmospheric pollution of Catania, a typical Mediterranean coastal town, is mainly contributed by vehicle exhaust emissions rather than industrial ones. Episodically, the city also suffers gaseous and ash emissions (plumes) from the nearby Mount Etna volcano. Thus, to discriminate between natural and anthropogenic contributions to stone decay on Catania monuments, black crusts and TSP were sampled within the urban area and subjected to specific analytical procedures (optical microscopy, X-ray powder diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy equipped with energy dispersive spectrometry, ionic chromatography and dual inlet mass spectrometry). Mineralogical, chemical and isotopic characterization of black crusts and TSP provided new insights concerning the partition of sulfate sources in this particular urban context. The influence of Mount Etna emissions on both TSP and black crusts compositions was shown. Nevertheless, the key role of anthropogenic sources in the total sulfate budget was confirmed, while sea spray and volcanic emissions were found to make subordinate contributions. Quantitative data useful for the identification of the threshold pollution levels for preventive conservation of Catania monuments were obtained.     

不同自然环境和城市功能区的土壤黑碳特征及来源研究综述

黑碳是由生物质和化石燃料等燃烧产生的一系列含碳物质,长期广泛分布于土壤、大气等多种载体中,且表现出不同的环境效应。土壤作为一种不可再生的自然资源,是人类生存与发展不可缺少的物质基础,也是支撑城市发展的空间和生态基础。土壤中的黑碳构成土壤有机碳库的重要组分,且影响着土壤肥力、结构、有机污染物等多方面。目前,对黑碳的研究集中在其对环境的影响,我国在这方面的研究开始较晚,特别是对土壤中黑碳的研究还处于起步阶段。本文详细分析了土壤黑碳的可能来源（自然火灾、人类农业活动、化石燃料燃烧以及汽车尾气排放等）,概括了常见的土壤黑碳来源辨析方法（黑碳形态特征分析、黑碳/有机碳比值分析、黑碳碳同位素分析）,总结了国内外对不同自然环境、不同城市功能区的土壤黑碳研究现状。最后,提出了全球黑碳研究亟待关注和解决的关键问题,以期为将来合理制定控制黑碳排放的相关政策,减缓黑碳对环境质量和人体健康的影响,提供重要的理论依据。     

Beyond public artopia: public art as perceived by its publics

Since the upsurge of public art in the 1980s, geographers have been critically analysing creative practices as drivers of urban development and regeneration. They have commonly framed perceptions of art in urban public space from the perspectives of its producers and planners. Yet, the fundamental purpose of public art is shaped by its publics, which comprise a multifaceted audience. Some scholars have held a brief for examining perceptions of public art through its publics, but let things go at that. This paper attempts to address this under-researched yet important field by presenting a survey of publics’ perceptions of selected public-artwork localities in Amsterdam, Rotterdam, Antwerp and Ghent. The publics’ perceptions were generally expressed in platitudes that were neither unreservedly positive nor unreservedly negative. But the distinct localities do show significant differences in publics’ perceived attractiveness of the public-artwork locality. These perceptions are further situated within publics’ cognitive, spatial, aesthetic, social and symbolic proximity to both the public artwork and its site. These empirical details provide insight into publics’ engagement with public art in particular places and thereby provide lessons for public-art-led urban planning. Moreover, this study instigates more solid qualitative research on this specific engagement.     

A literary geography of Soweto

Humanist inspired literary geography offers one avenue of enquiry into the study of place. Its prime intention is to untangle the subjective, personalised construction and connotations of place meaning. African literature offers a rich source of information into the black urban experience. The presentation focuses upon the literary interpretation of Soweto, South Africa's largest black township. The Sowetan environment emerges as a landscape of placelessness in which the overwhelming emphasis by white and black writers alike is upon relating appalling conditions in an austere and hostile environment.     

The early twentieth-century “Black Metropolis”: urban geographic principles

Did Black Metropolises, that is, large black communities in major cities, hold unique opportunities that helped blacks to advance occupationally in the early twentieth century? The present study addresses this question, using Census data to test hypotheses, based on urban geographic principles, about the distribution of Black Metropolises’ locational advantages. The results show that blacks’ representation in key middle-to-upper-status occupations declines precipitously across Black Metropolises, often following an exponentially descending Pareto curve, suggesting that blacks’ opportunities to enter such occupations are concentrated into a small number of large urban black communities. The results further indicate that the locational-advantage benefits of the largest, most segregated, and most centrally positioned Black Metropolises are limited to a few high-status professions and a narrow range of occupations involving cultural expression, entertainment, and public service. These findings challenge claims that blacks’ socioeconomic standing was substantially uplifted in the early twentieth century by unique opportunities in large black communities of major cities.     

成都市城市道路塌陷成因及快速探测方法

城市道路塌陷严重危害城市公共安全,对城市道路塌陷隐患进行快速、准确、绿色的探测,有助于减少城市地下病害发育,提升城市安全运营能力。通过调查分析,成都市城市道路塌陷的主要成因包括地质结构复杂、地下水丰富、人类工程活动频繁等。采用车载三维探地雷达对城市道路进行快速探测,建立了以探测、解译、验证、评估、成果及信息化管理为系统的探测体系。实践表明,车载三维探地雷达是快速探测城市道路塌陷隐患的有效方法。     

Hydrogeological and mineralogical analysis of the pre‐Romanesque monument of Santa María del Naranco,Asturias, Spain

The church of Santa María del Naranco is an important monument from the pre‐Romanesque period of Asturian art. Here we present research that locates the probable source of travertine used in the construction of a vault within this monument. Since the genesis of this travertine is associated with spring activity, and archival evidence suggests that stone procurement during this period tended to be local, we surveyed existing carbonated aquifers within a 5‐km radius of the monument. We identified a spring (Sopeña) with an associated outcrop of discontinuous travertine that appeared to have been quarried in the past. We conducted X‐ray powder diffraction, electron microprobe, and inductively coupled plasma mass spectrometry analyses of samples extracted from the suspected travertine source, an additional more distant travertine quarry for comparison, and the vault. Matching mineralogy and geochemistry indicate that the Sopeña travertine was the probable source of rock material used in the construction of the vault. This study provides insight into local ancient monument construction and can assist in procuring original stone material for historical restoration. © 2010 Wiley Periodicals, Inc.     

Contextualizing public art production in China: The urban sculpture planning system in Shanghai

This research examines urban sculpture production to understand how a public art (called “urban sculpture” in China) scene is produced in the country, using Shanghai as a case study. Theories of Chinese urban planning are innovatively applied. The findings generate theoretical implications for “contextualizing” public art production in geographical studies. All the chief officials in charge of urban sculpture planning in Shanghai were interviewed, and documentary analyses were conducted. The article argues that urban sculptures are conceived of as both symbolic capitals and didactic tools in the cultural policies of Shanghai. Urban sculpture planning plays an important role in coordinating and manipulating development of symbolic resources to advance urban entrepreneurialism within the ideological framework of the Communist Party’s leadership. The main features of the urban sculpture planning system of China are twofold: (1) The two-tier planning structure combines a master plan at the municipal level and detailed plans for site analysis and design guidance at the district level, all collaboratively working to create an attractive city image for urban entrepreneurialism. (2) An authoritarian style of planning system controls the contents and expression of urban sculpture within the ideological framework of urban sculpture planning.     

Nickel,molybdenum, and cobalt in the black shales of the Bazhenov Formation of the West Siberian basin

It was shown that the contents of Ni, Mo, and Co in the siliceous clay black shale rocks of the normal sections of the Bazhenov Formation are several times higher than the global mean contents of these elements in black shales. These rocks have the highest contents of pyrite and organic carbon and show evidence for strongly reducing formation conditions at the slowest background rate of sedimentation of their material. A transition from the siliceous clay rocks to the mudstones of normal section, which are considered as turbidites, and further to the mudstones and clayey silt rocks of the so-called anomalous sections (deposits of submarine deltas and canyons) is accompanied by sequential depletion in pyrite and organic carbon, a decrease in indicators of the reduction level of the sedimentation environment, and an increase in sedimentation rate and clay material content. Simultaneously, the contents of the elements of interest decreases in the sequence Mo > Ni > Co. In the rocks of anomalous sections, the contents of these elements decrease to the level of their mean abundances in clays.     

A comparison of black claystones,lignites and dump materials from the Maritsa Iztok Coal Basin,Bulgaria, using organic geochemical proxies

Geochemical analysis of dump materials from the opencast Maritsa Iztok mines, Bulgaria, was carried out based on biomarker assemblages of hydrocarbon fractions. Organic matter (OM) and secondary transformations in three representative samples (massive black claystones and materials from the Iztok and Staroselets dump sites) were studied using geochemical proxies.A number of differences were recognised in the respective OM compositions of the samples compared to both published data and between the individual dump samples themselves. The ОM of the studied samples was found to be polar, but also contains some apolar compounds. It consists mainly of resins and asphalthenes. Claystone OM is of the dispersed type, with intense oxidative-reductive interactions in a lacustrine environment resulting in its transformation into an inert material. Dump sample kerogen is of Type II and mixed Type II/III. In all samples, “odd” numbered n-alkanes are found in higher amounts. Diterpenoids (С₁₉, С₂₀) with pimarane, abietane and phyllocladane skeletons are preponderant. Tri- and tetracyclic terpenoids and steranes have been identified in the black claystones OM only. Hopanes are present in low amounts in extractable OM from all three samples. Biomarkers indicate that black claystone OM is formed from aqueous flora, with a minor supply of gymnosperms (mainly G. Sequoia). Iztok Dump OM is structured by higher plants with an aqueous vegetation input. The Staroselets Dump OM formation is assigned to an active microbial reworking of aqueous vegetation and bacteria with a minor coniferous supply. Different geochemical parameters admit anoxic stratified bottom waters for the black claystones with an addition of deep water stagnation for Staroselets sample in a Maritsa Iztok Basin (MIB) aqueous environment.An attempt was also made to track the effect of secondary processes (oxidation, destruction, dearomatisation), temperature, water drainage and wash-out on dump materials. Leaching and weak degradation processes in the MIB dump environment are likely for a time span of ca. 40–50 years, considering the low percentage of short-chain n-alkanes, long-chain prevalence and low Pr/nC₁₇ and Ph/nC₁₈ ratios, with the Iztok Dump sample experiencing more advanced transformations.     

贵州开阳白马洞铀矿化岩层地球化学特征

贵州开阳白马洞铀矿是重要的蚀变型铀矿,通过对白马洞清虚洞组黑色蚀变岩及白云岩风化红粘土和寒武系牛蹄塘组黑色页岩的常量元素、微量元素和稀土元素组成的分析研究,发现铀元素含量与Re、Se、Pb、Cu、As、Sb、Tl、Zn、Ni、Mo、Co、S含量为正相关关系,铀含量高,则Re、Se、Pb、Cu、As、Sb、Tl、Zn、Ni、Mo、Co、S含量也高,其中As、Co、Mo、Ni、Re、Tl、Zn、S具有显著的正相关性,而且地表土壤中Se、V、Mo 等元素的富集是铀矿找矿的主要标志之一。根据白马洞清虚洞组、寒武系牛蹄塘组黑色页岩、灯影组硅化白云岩的稀土元素配分模式分析,硒富集和铀矿化矿源层不仅是牛蹄塘组黑色页岩,可能有更深部的矿源存在。认为硒富集区是铀矿找矿远景区域;古代炼汞矿渣富集铀矿,值得开发利用和治理。     

The Angera stone: a challenging conservation issue in the polluted environment of Milan (Italy)

The Angera stone is a sedimentary Triassic dolostone mainly composed of dolomite, which was widely employed in the Lombard architecture. In the present work, the study of the Angera stone of the ‘Cortile del Richini’, a masterpiece of the Lombard baroque, is discussed as an example of a particularly challenging conservation issue. The courtyard suffered from a particularly troubled conservative history and the highly polluted urban environment of Milan provided very favourable conditions for the decay of such a delicate stone type. The last extensive conservative intervention was performed during the nineties due to massive black crust formation and granular disintegration of the stone. Almost 20 years later, a thorough study of the stone has been aimed at the definition of a long-term maintenance project. The Angera stone has been investigated in order to define an updated version of its state of conservation, as well as to track any changes in the degradation mechanisms due to the environmental variations of the Milan city centre. In particular, the soluble salts’ content of the stone substrate has been evaluated as an indicator of the damage level. The results highlighted that the stone is currently in critical condition: An extensive sulphation process is taking place, leading to the chemical transformation of the dolomitic substrate into gypsum. Moreover, the powder deposits affecting the stone surfaces have a similar composition to those generally found in the black crusts growing in urban environment. Therefore, they can be considered as precursor of this particularly dangerous decay mechanism.     

北京市不同功能区土壤黑碳的含量特征及其来源分析

随着城市迅猛发展,城市土壤性质发生显著变化,不同功能区之间呈现明显差异性。为了深入讨论人为影响方式和程度、污染来源的差别对土壤碳库(特别是黑碳)的影响,本研究以北京市为对象,对比研究了城区和郊区不同功能区(公园、居民区、道路绿化带)土壤有机碳(SOC)含量、黑碳(BC)含量以及含量比值(BC/SOC)的特点,并通过BC/SOC指标对土壤受到的人类活动影响方式和程度进行详细讨论。结果显示,北京市城区不同功能区的土壤SOC富集程度不同,且公园和居民区土壤在人为管理下SOC含量趋于平均;而郊区不同功能区的SOC含量值接近,表明其受人为影响较小,更接近于自然土壤。城区不同功能区的土壤BC含量存在较大差异,由大到小是公园(0.60%~2.28%,平均值为1.56%)、道路绿化带(0.12%~2.20%,平均值为0.62%)、居民区(0.11%~1.15%,平均值为0.35%),其中公园内区域性的翻种、施肥使得BC大量聚集,道路绿化带受到来自交通环境的强烈影响;而郊区不同功能区的BC含量值低且接近,代表了区域土壤BC含量背景值。土壤BC/SOC总体介于0.11和0.5之间,且郊区BC/SOC小于城区,指示了化石燃料和生物质的燃烧均是城区和郊区土壤BC物质的来源,但所占比重不同,且城区是郊区土壤黑碳的重要来源。另外,城区个别地区BC/SOC显著偏高,反映了BC/SOC不但指示土壤污染程度,同时与城市化时间、特定的人类活动密切相关。     

Text, talk, things, and the subpolitics of performing place

This article tells the story of how a group of Dutch and Belgian citizens organized themselves to promote an area that they valued, to put it on the map, to raise awareness about its qualities, and to protect it from urban and industrial development. Our theoretical perspective focuses on the performative and political aspects of this place-making process and the discursive and material practices involved. We connect this to Beck’s concept of subpolitics.Our findings show how the group performed this place not only through text and talk - giving the area a name, using their knowledge and expertise to raise awareness about its values, lobbying and cooperating with decision-makers -, but also through things - installing art objects and information signs that articulate certain characteristics and values of the area. Our findings demonstrate the struggles involved in these performances. The group involved multiple perspectives on what the important values and characteristics of the area are and on what strategies would work best in trying to influence decision-making and protect the area. However, the use of expertise as the main strategy to gain influence excluded the more critical and activist strategies and privileging archaeological and historical values and characteristics came at the expense of attention on agricultural and natural values.Our findings make clear that performing place cannot be taken to be homogeneous and that it inevitably involves multiple perspectives and demands. The struggles, power relations and dynamics of inclusion and exclusion that this multiplicity implicates reveal a form of sub-politics that involves both politicization and depoliticization. Also, it is a form of subpolitics that is more diverse and ambiguous than Beck’s conceptualization presupposes by its emphasis on the role of outsiders as a homogeneous group.     

Minerals provide tints and possible binder/extender in pigments in san rock paintings (South Africa)

Minerals such as iron oxides and clays provide high tinting strength and improve the adhesive properties of pigments. In this study, we investigated the mineral composition of pigments from samples of San rock art. We used X‐ray diffraction and scanning electron microscopy to determine the mineral composition and micromorphology of pigments. Results showed that the major minerals in pigments in San rock art are whewellite, quartz, gypsum, hematite, and various alumino‐silicate minerals. The red hue in the pigment is due to hematite; gypsum and clays provide the white coloration, whereas black might be due to amorphous manganese compounds. We believe that whewellite with globular habit was extracted from plant sap (e.g., aloe vera) and added to the pigment, perhaps as binder, extender, or whitener. Whewellite with needle‐shaped morphology was present in cracks that developed in pigments and indicated an early stage of deterioration of the rock art. We propose that conservationists should seriously evaluate any change in the environmental conditions at the art site (e.g., removal of vegetation to improve touristic view) because such changes might significantly increase thermal fluctuations in pigments and promote crack formation and hence the decay of the San rock art. © 2008 Wiley Periodicals, Inc.     

Property-based redevelopment and gentrification: The case of Seoul, South Korea

The urban experiences of South Korea in times of its rapid urbanisation and economic growth show that wholesale redevelopment had been a dominant approach to urban renewal, leading to redevelopment-induced gentrification. This was led by a programme known as the Joint Redevelopment Programme, transforming urban space that was once dominated by informal settlements into high-rise commercial housing estates. This paper tries to explain how this approach was possible at city-wide scale in its capital city, Seoul. Through the examination of redevelopment processes in a case study neighbourhood, it puts forward three arguments. First, the development potential arising from the rent gap expansion through under-utilisation of dilapidated neighbourhoods provided material conditions for the sustained implementation of property-based redevelopment projects. Second, this paper critically examines the dynamics of socio-political relations among various property-based interests embedded in redevelopment neighbourhoods, and argues that external property-based interests have enabled the full exploitation of development opportunities at the expense of poor owner-occupiers and tenants. Third, South Korea had been noted for its strong developmental state with minimum attention to redistributive social policies. The Joint Redevelopment Programme in Seoul was effectively a market-oriented, profit-led renewal approach, in line with a national housing strategy that favoured increased housing production and home-ownership at the expense of local poor residents’ housing needs.     

Evidence for photic‐zone euxinia in the Early Albian Santana Formation (Araripe Basin,NE Brazil)

Organic matter from two black shale units in the Santana Formation, Araripe Basin, NE Brazil, has been studied to investigate the palaeoenvironmental conditions prevailing during formation of this famous fossil lagerstätte. Optical and organic geochemical analyses indicate a predominantly autochthonous source with very limited terrestrial input. Molecular fossils of green sulphur bacteria show that the water column was stratified with euxinic conditions reaching up into the photic zone. Thus, mass‐mortality events of fish may be explained by intrusion of sulphide‐containing waters. The low quantity of material derived from land plants in this interior marine setting is interpreted to reflect a consequence of enhanced marine productivity, resulting in dilution of the continental signal. Different depositional scenarios are proposed to explain our findings including (1) coastal erosion and nutrient leaching during a transgressive event, (2) intrusion of euxinic waters during an early Albian OAE or (3) an estuarine circulation pattern associated with thermohaline stratification.     

Environmental geochemistry: 40 years research at Imperial College,London, UK

This paper reviews the development of multi-purpose geochemical mapping and the progress of research in applied environmental geochemistry and health at Imperial College over the past 40 years. With funding from the research councils, UK government, EU, industry and NGOs, research has provided the basis for postgraduate training in areas ranging from the applications of geochemistry to plant, agricultural livestock and wildlife nutrition, to evaluating contamination from metalliferous mining and smelting, understanding the chemical nature of the urban environment and relationships between geochemistry and human health and disease. Examples include (1) the influence of Mo in marine black shales on the Cu nutrition of grazing cattle and sheep, (2) the importance of soil ingestion on trace element intake and metabolism and metal exposure in farm livestock, (3) the impacts of soil contamination from historical metalliferous mining and smelting on agriculture and human exposure to metals, including potential health problems from Cd at Shipham and from As in SW England, (4) the growth of urban geochemistry and the importance of Pb in the urban environment, (5) the health impacts due to Hg losses from the informal sector Au mining in Brazil, and (6) health issues relating to F^- excess and Se deficiency in China.     

Urban locations and Black Metropolis resilience in the Great Depression

Motivated by theoretical arguments about ethnicity and economics and by historical research on urban black communities in the United States, this paper investigates the resilience of the early twentieth-century Black Metropolis. The study tests hypotheses about changes during the Great Depression (1930–1940) in the advantages of various cities as locations of black communities’ ethnic economies, analyzing Census data on blacks’ representation in occupations reflecting the Black Metropolis’s professional, entrepreneurial, and cultural media pursuits. There is mixed support for the hypothesis that the nationally dominant urban centers of New York, Chicago, and Philadelphia had the most resilient Black Metropolises, a finding that casts doubt on claims that black communities in such key places enjoyed exceptionally favorable locational advantages. Yet, the results support the hypothesis that northern cities were, overall, more resilient locations than southern cities, particularly for black professionals and entrepreneurs, affirming the argument that the urban North’s Black Metropolises were vital economic opportunity centers for these black communities’ upper- and middle-classes.