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《Geoforum》2015
The right to food is increasingly evoked by a range of actors, but there is not sufficient critical analysis of distinct interpretations of what this right means in practice. Through examination of a mineral extraction project with agricultural implications, this article explores diverse human rights narratives and illuminates associated corporate efforts to minimize recognition of food as a fundamental right. A British mining company proposes the Phulbari open pit coal mine in an agriculturally important region of Bangladesh. Highly contested by affected populations, clashes in 2006 between the police and protestors turned deadly in the area. In February 2012, a group of UN Special Rapporteurs cautioned the Government of Bangladesh regarding human rights violations associated with the planned mine. They warned that the project would displace hundreds of thousands of people, while destroying fertile agricultural land. In contrast, an ongoing publicity campaign by the corporation attempts to promote their intervention as a positive step, fully compliant with international human rights and corporate social responsibility standards. Taking this case as an exemplar, the article illuminates the pursuit of mining profit and the distinct use of human rights narratives by corporations and UN Special Rapporteurs. These diverse actors represent the layering of voices weighing in on mineral extraction and associated right to food concerns. Collectively, these layered narratives represent a new terrain for the promotion and contestation of mining and highlight the need to scrutinize mining practices in light of social responsibility and human rights claims being voluntary and self-regulated. 相似文献
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Eastern Australian xenolith suites and lithospheric transition zones are re‐evaluated using new mineral analyses and thermo‐barometry. Some suites, including that defining the southeastern Australian geotherm, are not fully equilibrated. New pressure‐temperature estimates, based on experimental calibrations that allow for Cr and Ti in pyroxenes, differ from earlier results by up to 0.6 GPa and 250°C. The preferred Brey and Köhler 1990 thermo‐barometer indicates a shallower cooler garnet lherzolite transition under Mesozoic New South Wales (50 km depth at 980° C) than for Tertiary Tasmania (60 km depth at 1090°C). Deviations between palaeogeotherms may reflect: (i) higher temperature gradients for Tasmania and New South Wales (by 100°C/0.1 GPa) related to abnormally hot mantle; (ii) higher temperature gradients linked to more voluminous magmatism, largely Cenozoic in age; and (iii) complex temperature perturbations linked to different levels of magmatic intrusion. These deviations blur reconstructions of lithospheric assemblages, where temperature is determinable and pressure comes from an assumed geotherm. Potential errors in locating spinel lherzolite and crust‐mantle transition assemblages may reach 15 km in depth. The highest Tertiary geothermal gradients in Tasmania and northeastern New South Wales match those from regions of active lithospheric extension. The young southeastern Australian geotherm is decaying from a higher temperature equilibration, based on experimental work, and Mesozoic New South Wales geotherms trend towards the lower gradients of bounding cratons. 相似文献
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The Xiangshui to Mandal geoscience transect, which has a total length of 1,200 km, extends diagonally,from SE to NW, across the Sino-Korean plate and its ancient continental margin, passing through nine tectonicunits: the Subei-Jiaonan terrane, West Shandong block, North China rift basin, Taihang-Wutai block, Ordosblock, Hu-Bao (Hohhot-Baotou) Basin, Yinshan block and Inner Mongolian fold system. The graphic display of the transect is compiled according to the Guidelines for the Global GeoscienceTransect (GGT) Project on the basis of an integrated study of all available geological, geochemical andgeophysical data, thus bringing light to the process of cratonization of the Sino-Korean plate and its relation-ship with the transitional zone of the ancient continental margin, and the features of intraplate structures pro-duced by subsequent tectonic modifications and intraplate dynamics. 相似文献
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The Neoarchean (ca. 2.75 Ga) Luanga Complex, located in the Carajás Mineral Province in Brazil, is a medium-size layered intrusion consisting, from base to top, of ultramafic cumulates (Ultramafic Zone), interlayered ultramafic and mafic cumulates (Transition Zone) and mafic cumulates (Mafic Zone). Chromitite layers in the Luanga Complex occur in the upper portion of interlayered harzburgite and orthopyroxenite of the Transition Zone and associated with the lowermost norites of the Mafic Zone. The stratigraphic interval that hosts chromitites (∼150 meters thick) consists of several cyclic units interpreted as the result of successive influxes of primitive parental magma. The compositions of chromite in chromitites from the Transition Zone (Lower Group Chromitites) have distinctively higher Cr# (100Cr/(Cr + Al + Fe3+)) compared with chromite in chromitites from the Mafic Zone (Upper Group Chromitites). Chromitites hosted by noritic rocks are preceded by a thin layer of harzburgite located 15–20 cm below each chromitite layer. Lower Cr# in chromitites hosted by noritic rocks are interpreted as the result of increased Al2O3 activity caused by new magma influxes. Electron microprobe analyses on line transverses through 35 chromite crystals indicate that they are rimmed and/or extensively zoned. The composition of chromite in chromitites changes abruptly in the outer rim, becoming enriched in Fe3+ and Fe2+ at the expense of Mg, Cr, Al, thus moving toward the magnetite apex on the spinel prism. This outer rim, characterized by higher reflectance, is probably related to the metamorphic replacement of the primary mineralogy of the Luanga Complex. Zoned chromite crystals indicate an extensive exchange between divalent (Mg, Fe2+) cations and minor to none exchange between trivalent cations (Cr3+, Al3+ and Fe3+). This Mg-Fe zoning is interpreted as the result of subsolidus exchange of Fe2+ and Mg between chromite and coexisting silicates during slow cooling of the intrusion. A remarkable feature of chromitites from Luanga Complex is the occurrence of abundant silicate inclusions within chromite crystals. These inclusions show an adjacent inner rim with higher Cr# and lower Mg# (100 Mg/(Mg + Fe2+)) and Al# (100Al/(Cr + Al + Fe3+)). This compositional shift is possibly due to crystallization from a progressively more fractionated liquid trapped in the chromite crystal. Significant modification of primary cumulus composition of chromite, as indicated in our study for the Luanga Complex, is likely to be common in non-massive chromitites and the rule for disseminated chromites in mafic intrusions. 相似文献
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《Geoforum》2016
This article continues and expands the conversation initiated by Jørgensen on the need to rethink rewilding, which elicited a response from Prior and Ward. To spur further conversation, my response to both papers argues for two modes of discourse expansion: geographical and disciplinary. Although both articles gesture toward global rewilding sites, their discussions remain focused on European geographies. I offer James Feldman’s environmental history of the Apostle Islands to extend a geographical purview beyond European contexts. Secondly, I take up these papers’ implicit call for humanities scholars to join this conversation, and I argue for the relevance and importance of fictional writings to a debate regarding rewilding. I briefly introduce two recent fictional works and argue for their place in rewilding conversations based on the ability of imaginary writings to develop empathy. 相似文献
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《中国地球化学学报》2006,(Z1)
Taipingxi, Yichang, Hubei province, China, is situated on the left of the Three-Gorges Dam of the Yangtze River. The bedrock is granite. Yhe Three-Gorges Project began to sluice in June, 2004. The contents of magnesium, aluminum and fluoride in rock and s… 相似文献
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《Geoforum》2017
This paper explores the circulation of images and words about fish that has been certified or endorsed as ‘sustainable seafood’. Specifically, our discourse analysis – of data collected from online, magazine, and television media sources targeted at North Americans – interrogates the constitution of sustainable seafood as a tenable solution to fisheries limits. We reveal three narratives populated by different messages and personalities that describe spaces of fish harvest, crisis, and consumption. By exploring the multifaceted ways that prominent organization National Geographic mediates sustainable seafood, we also show that the narratives rest easily with each other, and when taken together, present what seems like a cohesive set of cultural instructions for viewers and readers. Throughout, we question what is not present in the narratives and highlight how sustainable seafood as a cultural phenomenon opens up new material and political-economic opportunities for some. In sum, we trace a cultural politics that constitutes sustainable seafood as a tenable solution to fisheries limits, obscures the complexities of industrial fisheries, and generates new opportunities for accumulation. Our analysis and discussion pushes research regarding the contemporary cultural politics of sustainability towards an array of media organizations and formats and encourages further consideration of intimate identity politics. 相似文献
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Forward Modeling of Gravity, Gravity Gradients, and Magnetic Anomalies due to Complex Bodies 总被引：3，自引：0，他引：3
On the basis of the results of improved analytical expression of computation of gravity anomalies due to a homogeneous polyhedral body composed of polygonal facets, and applying the forward theory with the coordinate transformation of vectors and tensors, we deduced both the analytical expressions for gravity gradient tensors and for magnetic anomalies of a polygon, and obtained new analytical expressions for computing vertical gradients of gravity anomalies and vertical component of magnetic anomalies caused by a polyhedral body. And also we developed explicitly the complete unified expressions for the calculation of gravity anomalies, gravity gradient, and magnetic anomalies due to the homogeneous polyhedron. Furthermore, we deduced new analytical expressions for computing vertical gradients of gravity anomalies due to a finite rectangular prism by applying the newly obtained expressions for gravity gradient tensors due to a polyhedral target body. Comparison with forward calculation of models shows the correctness of these new expressions. It will reduce forward calculation time of gravity-magnetic anomalies and improve computational efficiency by applying our unified expressions for joint forward modeling of gravity-magnetic anomalies due to homogeneous polyhedral bodies. 相似文献
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A.R. Selby 《Geotechnical and Geological Engineering》1999,17(3-4):351-371
Tunnelling through soils results in ground loss, causing surface settlements and transverse movements. Where the tunnel drive passes below an existing structure, it is important to estimate the effects upon the structure. However, the free ground deformations should not simply be imposed upon a structure, because the structure contributes to stiffening of the ground. A computational soil-structure interaction analysis is required, to otain detailed stress–deformation response. First, linear finite element and Lagrangian finite difference methods are used to estimate ground movements due to a tunnel in free ground, and the results are compared with values based on empirical equations. The two linear methods and an additional hybrid FE method are then used to assess with soil-structure interaction; two cases of a typical short wall and a long wall lying across the route of tunnels of different depths. The results support the validity of the hybrid method which is used to estimate interactive ground settlements for comparison with a reported case of tunnelling below a building in central London. A more detailed case study is then undertaken to assess building damage caused by gross settlements during tunnelling in mixed soils, at a site in Workington, west Cumbria. A survey allowed estimation of free ground movements. Analysis by the hybrid method on the soils plus uncracked structures indicated intolerable horizontal stresses. Re-analysis with major cracks introduced into the structures resulted in close agreement between measured and computed settlements. 相似文献
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High-frequency (5–20 Hz) seismic signals precursory to and embedded within the June 17, 2017 ML?=?4 earthquake–landslide event are analyzed. This event in western Greenland generated a tsunami in Karrat fjord inundating Nuugaatsiaq village 32 km distant. Spectrogram and wavelet analyses of seismic data from the Greenland Ice Sheet Monitoring Network (GLISN) corroborate observations of seismic precursors at Nuugaatsiaq reported by Poli (Geophys Res Lett 44:8832–8836, 2017) and Caplan-Auerbach (in: AGU fall meeting abstracts, 2017) and reveal additional high-frequency arrivals being generated after the apparent initiation of fault rupture. New observations of seismic precursors 181 km from the Event at Upernavik, Greenland are correlated with those seen at Nuugaatsiaq. Wavelet analysis presents?>?100 significant energy peaks accelerating up to and into the earthquake–landslide event. The precursor events show a distinct, power law distribution, characterized by b values of ~?2.4. Results are compared and contrasted with small precursors observed in the studies of a natural chalk cliff landslide at Mesnil-Val, Haute Normandie, France. The earthquake–landslide appears to have been initiated by seismic precursors located at the fault scarp, leading to a small seismic foreshock and small landslide initiation, followed by a larger earthquake at the fault scarp, precipitating the primary landslide into the Karrat Fjord, which caused the subsequent tsunami.
相似文献17.
The Everglades (Florida, USA) is one of the world’s larger subtropical peatlands with biological communities adapted to waters low in total dissolved solids and nutrients. Detecting how the pre-drainage hydrological system has been altered is crucial to preserving its functional attributes. However, reliable tools for hindcasting historic conditions in the Everglades are limited. A recent synthesis demonstrates that the proportion of surface-water inflows has increased relative to precipitation, accounting for 33% of total inputs compared with 18% historically. The largest new source of water is canal drainage from areas of former wetlands converted to agriculture. Interactions between groundwater and surface water have also increased, due to increasing vertical hydraulic gradients resulting from topographic and water-level alterations on the otherwise extremely flat landscape. Environmental solute tracer data were used to determine groundwater’s changing role, from a freshwater storage reservoir that sustained the Everglades ecosystem during dry periods to a reservoir of increasingly degraded water quality. Although some of this degradation is attributable to increased discharge of deep saline groundwater, other mineral sources such as fertilizer additives and peat oxidation have made a greater contribution to water-quality changes that are altering mineral-sensitive biological communities. 相似文献
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This is a Reply to Hechenleitner and collaborators Comment, who proposed a Cretaceous age for the whole Llanos Formation (central Argentina, Sierras Pampeanas Province), based on neosauropod fossils, instead of Miocene as originally proposed by Ezpeleta et al. (2006) and Dávila et al. (2007). However, red beds that underlay the thick paleosoils of the Llanos Formation provided nine detrital U–Pb Paleogene (62 Ma, earliest Cenozoic) ages on zircon grains (Astini et al., 2009, Ezpeleta, 2009). On the base of this evidence, and other mammal remnant within the Sierras Pampeanas (where the Llanos Formation develops), we proposed this is a condensed unit with Mesozoic ages at the bottom and Mio-Pliocene (likely younger) to the top. 相似文献
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Hurricane Floyd in September 1999 caused disastrous flooding from South Carolina to Massachusetts in the United States, with particularly severe and prolonged flooding in eastern North Carolina resulting in record flood-flow loadings of freshwater and contaminants to Pamlico Sound, North Carolina. The inland flooding, water quality, and loadings to Pamlico Sound were determined as part of a multi-agency response to the floods and in an effort to understand the effects of the floods on the greater Pamlico Sound Basin. All major river basins draining to Pamlico Sound experienced floods at the 500-yr recurrence level. The volume of flood waters entering Pamlico Sound during September–October 1999 was estimated to be equivalent to about 95% of the volume of Pamlico Sound, meaning that flood waters could have essentially displaced most of the water present in Pamlico Sound. Nitrogen and phosphorus loads to the Pamlico River estuary and Neuse River estuary, the two principal estuaries draining to Pamlico Sound, in a 36-d period during the flooding were between 50–90% of the long term average annual loads. Pesticide concentrations in flood waters were surprisingly high, given the amount of dilution produced by the floodwaters. 相似文献