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1.
《Geoforum》2013
This paper forms part of an endeavour to elicit the cultural-geo-politics of rapprochement tourism between China and Taiwan from a grounded approach. It seeks to examine cross-strait tourists’ travel experiences on ‘the other side’ through the lens of ‘border’, ‘materiality’ and ‘identity’ in an attempt to move beyond the often state-centric analyses of cross-strait ties. Discussion shows that travel documents that are close to the personal or those that are part and parcel of a touring experience are far from inert; they participate in the social and political lives of their owners, feature in bordering practices between the Chinese and the Taiwanese, and are often platforms through which identities are performed. Importantly too, as the various travel narratives reveal, the ubiquitous border certainly does not exist only in its physical form; imagined and perceived social borders are equally potent in (re)shaping cross-strait relations. A study that captures the often neglected field of comparative tourists’ travel experiences is timely in the advent of a warming relationship between China and Taiwan and the unprecedented increase in tourism exchanges that ensues. 相似文献
2.
Mantle-derived carbonatites provide a unique window in the understanding of mantle characteristics and dynamics, as well as insight into the assembly and breakup of supercontinents. As a petrological indicator of extensional tectonic regimes, Archean/Proterozoic carbonatites provide important constraints on the timing of the breakup of ancient supercontinents. The majority of the carbonatites reported worldwide are Phanerozoic, in part because of the difficulty in recognizing Archean/Proterozoic carbonatites, which are characterized by strong foliation and recrystallization, and share broad petrologic similarities with metamorphosed sedimentary lithologies. Here, we report the recognition of a ~1.85 Ga carbonatite in Chaihulanzi area of Chifeng in north China based on systematic geological, petrological, geochemical, and baddeleyite U-Pb geochronological results. The carbonatite occurs as dikes or sills emplaced in Archean metasedimentary rocks and underwent intense deformation. Petrological and SEM/EDS results show that calcite and dolomite are the dominant carbonate minerals along with minor and varied amounts of Mg-rich mafic minerals, including forsterite (with Fo > 98), phlogopite, diopside, and an accessory amount of apatite, baddeleyite, spinel, monazite, and ilmenite. The relatively high silica content together with the non-arc and OIB-like trace element signatures of the carbonatite indicates a hot mantle plume as the likely magma source. The depleted Nd isotopic signatures suggest that plume upwelling might be triggered by the accumulation of recycled crust in the deep mantle. As a part of the global-scale Columbia supercontinent, the Proterozoic tectonic evolution of the North China Craton (NCC) provides important insights into the geodynamics governing amalgamation and fragmentation of the supercontinent. The Paleo-Mesoproterozoic boundary is the key point of tectonic transition from compressional to extensional settings in the NCC. The newly identified ~1.85 Ga carbonatite provides a direct link between the long-lasting supercontinental breakup and plume activity, which might be sourced from the “slab graveyard,” continental crustal slabs subducted into asthenosphere, beneath the supercontinent. The carbonatite provides a precise constraint of the initiation of the continental breakup at ~1.85 Ga. 相似文献
3.
《Journal of Structural Geology》2001,23(6-7):963-971
It has been claimed that rigid porphyroblasts which grow before or during folding and concurrent cleavage development do not rotate with respect to the geographical reference frame (GRF), even if the straining is non-coaxial (Bell, 1985, Bell and Johnson, 1990). The explanation offered is based on strain partitioning. It is argued that the initial orientations of early fabrics included as internal foliations (Si) in the porphyroblasts have been preserved after polyphase deformation, and even after successive orogenies. According to the strain partitioning model, the porphyroblasts are fixed in domains of coaxial straining (microlithons) and are isolated from the non-coaxial straining associated with the enveloping septa (Se). This hypothesis, and also its discussions both pro and contra, suffer from insufficient attention to reference frames. We therefore attempt to demonstrate: (a) the need for rigorous treatment of reference frames in geological interpretations; (b) that, in a folding situation, grains that do not rotate with respect to their immediate matrix generally rotate with respect to the GRF; (c) that lack of porphyroblast rotation with respect to the GRF demands a rare folding mechanism (slip fold model); and (d) that the non-rotation hypothesis is in conflict with heterogeneous deformation (cleavage refraction). Finally, we question the validity of the evidence in a study by Fyson (1980), cited in support of non-rotation with respect to the GRF during folding. Fyson reported orientations of Si that are constant, after folding, over a large area; this scenario is a product of selective data acquisition. In summary, our investigation shows that the lack of porphyroblast rotation with respect to a GRF during folding, while possible, is not universal. The development of microstructures (e.g. curved Si) is only related to the local deformation path, the characterisation of which does not rely on the GRF. 相似文献
4.
《地学前缘(英文版)》2022,13(2):101339
The current margins of the North China and Yangtze Cratons provide arguably the best examples globally of anomalously high mineral endowment within a 100 km buffer zone, hosting 66 diverse world-class to giant ore systems that help explain China’s premier position as a producer of multiple metal and mineral commodities. After the cratonization of these crustal blocks during the Neoarchean-Paleoproterozoic, with incorporation of iron ores on assembled micro-block margins, the margins of the cratons experienced multiple convergence and rifting events leading to metasomatism and fertilization of their underlying sub-continental lithospheric mantle. The rifted margins with trans-lithosphere faults provided pathways for Cu-Au (Mo-W-Sn)-bearing felsic to Ni-Cu-bearing ultrabasic intrusions and REE-rich carbonatite magmas, and for the development of marginal sedimentary basins with both Cu-Pb-Zn-rich source units and reactive carbonate or carbonaceous host rocks. There was diachronous formation of hydrothermal orogenic gold, antimony, and bismuth systems in the narrow orogenic belts between the cratons. Complexity in the Mesozoic Paleo-Pacific subduction systems resulted in asthenosphere upwelling and lithosphere extension and thinning in the North China Craton, leading to anomalous heat flow and formation of orogenic gold deposits, including those of the giant Jiaodong gold province on its north-eastern margin. These gold deposits, many of which formed from fluids liberated by devolatilization of previously metasomatized sub-continental lithospheric mantle, helped propel China to be the premier gold producer globally. The thick sub-continental lithospheric mantle of the cold buoyant cratons helped the preservation of some of the world’s oldest porphyry-skarn and epithermal mineral systems. Although craton margins globally control the formation and preservation of a diverse range of mineral deposits, China represents the premier example in terms of metal endowment due to the anomalous length of its craton margins combined with their abnormally complex tectonic history. 相似文献
5.
《Geoforum》2014
The recent emergence of the Fairtrade certification of gold in Latin America and sub-Saharan Africa promises a radical new direction for the environmental governance of artisanal and small-scale mining (ASM). In doing so, it aims to tackle the longstanding environment and development challenges of the sector which mainstream policy has failed to alleviate. The move towards more responsible ASM practices is premised on the strategic deployment of a Fair Trade discourse that argues for its operators to be recognized not as criminals, but as valued and formalized parts of their broader economies. It is argued in this paper that this development intervention should be read within a social and environmental justice framework, one which directly answers the call from political geography for ‘compelling accounts’ of positive representations of the sector.Through a discourse analysis of 10 years of media reports, interviews and recorded life histories of key ASM and Fair Trade stakeholders in Tanzania, it shows how three strands of justice (conceptualized in terms of fairer distribution, procedure and recognition) are articulated by the Fair Trade gold movement and critically assesses the politics behind such a deliberate strategy. In particular, it argues that recognition is a key part of justice that has been underplayed by erstwhile analyses of Fair Trade. Through a case study of Tanzania, it is concluded that although significant progress has been made in terms of arguing for greater recognition for ASM operators, there remains a need to better link discourse with practice in establishing greater distributional justice. 相似文献
6.
Wenbo Su Warren D. Huff Frank R. Ettensohn Xiaoming Liu Ji'en Zhang Zhiming Li 《Gondwana Research》2009,15(1):111-130
The K-bentonite, black shale and flysch successions at the Ordovician–Silurian transition in South China have been the subject of comprehensive investigations relative to the probable accretion of the Yangtze Block and the questionable Cathaysia Block. First, the geochemical analyses of K-bentonites show that the parent magma originated in syn-collisional, volcanic-arc and within-plate tectonic settings, which produced mainly intermediate-to-felsic series magmas, associated with continuous collision and subduction of paleo-continental blocks/arcs. Further, the regional distribution of K-bentonite thickness indicates that voluminous explosive volcanism was located in the present southeastern shoreline provinces of China. Secondly, northwestwardly migrating, Ordovician–Silurian, transitional flysch successions, and the accompanying diachronous K-bentonite-bearing black-shale interval, as well as the related, overlying, shallowing-upward succession at the interior of the Yangtze Block, developed as an unconformity-bound sequence that mirrors foreland-basin tectophase cycles in the Appalachian basin. The above features suggest that the sequence accumulated in a similar foreland basin, which formed in response to adjacent deformational loading in a northwesterly migrating orogen located to the southeast. Geochemical and paleocurrent data from the turbiditic flyschoid sandstones also support these depositional settings. Accordingly, it seems that all criteria strongly support the presence of an Ordovician–Silurian, subduction-related orogen resulting from collision with a block to the southeast that must have been the original “Cathaysia Block” of Grabau and later workers. The K-bentonite, black-shale and flysch successions can be regarded as distal, foreland responses to the continuous northwestward collision and accretion of the Cathaysia Block to the Yangtze Block. Hence, we prefer to suggest that the suture zone with the sensu stricto Cathaysia Block probably developed along previously identified late Early Paleozoic suture relicts in the shoreline provinces of southeast China. On the other hand, although accretion of fragments with Cathaysian affinities to the Yangtze Block may have begun as early as Middle to Late Proterozoic time, the Ordovician–Silurian orogeny described above probably reflects the final phase of accretion between the two blocks. Moreover, when combined with similar peri-Iapetan orogenic events in other areas during the same period, this accretion event may have been part of a major stage of global tectonic reconstruction in the evolution of Gondwana. 相似文献
7.
《International Geology Review》2012,54(6):672-694
The Great Xing’an Range in Northeast China is located in the eastern part of the Central Asian Orogenic Belt. From north to south, the Great Xing’an Range is divided into the Erguna, Xing’an, and Songliao blocks. Previous U–Pb zircon geochronology results have revealed that some ‘Precambrian metamorphic rocks’ in the Xing’an block have Phanerozoic protolith ages, questioning whether Precambrian basement exists in the Xing’an block. We present laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) U–Pb dating results for zircons from suspected Precambrian metamorphic rocks in the Xing’an block. Meta-rhyolites of the Xinkailing Group in Nenjiang yield magmatic ages of 355.8 Ma. Detrital zircons from phyllites of the Xinkailing Group in Duobaoshan yield populations of ca. 1505, ca. 810, and ca. 485 Ma, with the youngest peak constraining its depositional age to be <485 Ma. Zircons from amphibolitic gneisses of the Xinkailing Group in Nenjiang have magmatic ages of 308.6 Ma. Mylonitic granites of the Xinkailing Group in Nenjiang have zircon magmatic ages of 164 Ma. Detrital zircons from two-mica quartz schists of the Luomahu Group in the Galashan Forest yield ca. 2419, ca. 1789, ca. 801, ca. 536, ca. 480, and ca. 420 Ma, with the youngest peak indicating its depositional age as <420 Ma. Detrital zircons from mylonitized sericite–chlorite schist of the Ergunhe Formation in Taerqi yield populations of 982–948, ca. 519, and ca. 410 Ma, with the youngest peak demonstrating that its depositional age is <410 Ma. These zircon ages for a range of lithologies show that the Great Xing’an Range metamorphic rocks formed during the Phanerozoic (164–485 Ma) and that this crust is mostly Palaeozoic. Based on these results and published data, we conclude that there is no evidence of Precambrian metamorphic basement in the Xing’an block. In summary, the age data indicate that Precambrian metamorphic basement may not exist in the Xing’an region. 相似文献
8.
Chiung-wen Hsu 《Natural Hazards》2013,69(1):39-57
This study explored the phenomenon of “star disaster-affected areas” created by media in Taiwan and its consequences. Taitung County was chosen as the study subject since it was covered in a biased large amount in 2009 Typhoon Morakot unprecedentedly. A content analysis of four major newspapers, in-depth interviews, and field research in Chialan and Dawu Township founds that media is the key player to create “star disaster-affected areas.” The factors of being “star disaster-affected areas” are the degree of impacted severity in the areas, the numbers of affected residents, casualty and death tolls, accessibility to affected areas, and most importantly human interests and visual impacts for better media storytelling. The consequences include uneven resources distributions and unfair reaction and recovery policies. This study provided implications for media workers, disaster management actors, residents, and media scholars to revisit ethics and theory to fit it the characteristics of disaster news and above all, disaster and communication scholars to develop an interdisciplinary study to facilitate disaster management. 相似文献
9.
《Earth》2006,74(1-4):63-78
The Neoproterozoic Ibex Formation (Death Valley region, California) is commonly interpreted as a coeval basinal facies to the Noonday Dolomite carbonate platform. However, in some areas (e.g., the Black Mountains, Death Valley), the Ibex Formation is found to rest on the eroded surface of the lower Noonday Dolomite and older units. Sediment-filled grikes root from the top of the eroded lower Noonday Dolomite, followed by the subsequent deposition of the Ibex Formation. Thus, the lower Noonday Dolomite is not considered coeval with all of the Ibex Formation as they are separated by a significant unconformity.At the type section in the Ibex Hills, the basal Ibex Formation commonly consists of polymict conglomerate and laminated mudstone; the upper surface of the mudstone is pierced by large angular clasts of underlying units, including distinctive lower Noonday Dolomite tubestone lithotypes. Here, a finely-laminated pink dolostone that records negative δ13C values caps the basal Ibex conglomerate.Several interpretations of the new observations are possible. The erosional unconformity upon which the Ibex is deposited may be glacio-eustatic in origin, the basal conglomerate would represent glaciogenic ice rafted debris, and the overlying dolostone is a classic cap carbonate (noted atop many Neoproterozoic glacial deposits worldwide). Combined with the record from underlying units, the Death Valley succession would then unambiguously record three discrete Neoproterozoic ice ages with cap carbonates in a single succession. Alternatively, the sequence boundary could represent local tectonic activity rather than glacioeustacy. 相似文献
10.
《Geoforum》2017
Over the past three decades, China has managed to maintain and even increase grain production in the context of rapid industrialization and urbanization through a process of internal spatial fix in which grain production is relocated to and concentrated in less developed inland regions. However, the fix created political and environmental problems that will undermine it in the future. Using national statistical data and two case studies, the paper demonstrates how the fix has been a result of complex interactions between central and local actors and is a key factor shaping China’s trajectories of food politics and agrarian transitions. It also reveals that confronting the underproduction crisis of food under capitalist accumulation China has first sought to produce sufficient grain within its national border rather than rely on overseas resources. 相似文献
11.
12.
In this paper, temporal dynamics of eco-environmental changes in coastal areas of China during 1981–2000 are investigated
based on four key surface parameters including normalized difference vegetation index (NDVI), thermal index, moisture index
and surface broadband albedo derived from quantitative remote sensing techniques and meteorological data. Firstly, land surface
temperature (LST) and land surface broadband albedo are retrieved by the split-window algorithms and high-order polynomial
regression method, respectively, using NOAA/AVHRR series images. Then, moisture index and thermal index, indicators of climate
and moisture conditions in the study area, are computed from meteorological data and LST using principal component analysis
(PCA). Finally, long-term dynamics of these eco-environmental factors and the reasons responsible for these changes are analyzed
further. The results show that during the years from 1981 to 2000, the study area experienced a gradual increase in annual
NDVI and climate factors and a decrease in surface annual broadband albedo, which indicates that the coastal thermal and moisture
conditions and the subsistence conditions of natural vegetation have changed to a considerable extent. According to the results,
a warming and wetting tendency over the last two decades is obvious in the China’s coastal zone that are mainly due to land
use changes as of growing urbanization, exhaust emissions from industries and transportations and, partly global climate change.
Uncontrolled rapid development of the study area may be blamed for these negative changes as a major driving force. The positive
feedback mechanisms between albedo, NDVI and climate factors also partly explain these changes. This study suggests that the
method integrating biophysical parameters retrieved from remote sensed images and meteorologic data provides a novel and feasible
way to monitor large scale eco-environmental changes.
相似文献
Q. QinEmail: |
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14.
The premise of the Wilson et al. comment is that the Ti-in-quartz solubility calibration (Thomas et al. in Contrib Mineral
Petrol 160:743–759, 2010) is fundamentally flawed. They reach this conclusion because P–T estimates using the Ti-in-quartz calibration differ from their previous interpretations for crystallization conditions of
the Bishop and Oruanui rhyolites. If correct, this assertion has far-reaching implications, so a careful assessment of the
Wilson et al. reasoning is warranted. Application of the Ti-in-quartz calibration as a thermobarometer in rutile-free rocks
requires an estimation of TiO2 activity in the liquid ( (liquid–rutile); referenced to rutile saturation) and an independent constraint on either P or T to obtain the crystallization temperature or pressure, respectively. The foundation of Wilson et al.’s argument is that temperature
estimates obtained from Fe–Ti oxide thermometry accurately reflect crystallization conditions of quartz in the two rhyolites
discussed. We maintain that our experimental approach is sound, the thermodynamic basis of the Ti-in-quartz calibration is
fundamentally correct, and our experimental results are robust and reproducible. We suggest that the reason Wilson et al.
obtain implausible pressure estimates is because estimates for T and they used as input values for the Ti-in-quartz calibration are demonstrably too high. Numerous studies show that Fe–Ti oxide
temperature estimates of some rhyolites are substantially higher than those predicted by well-constrained phase equilibria.
In this reply, we show that when reasonable input values for T and (liquid–rutile) are used, pressure estimates obtained from the Ti-in-quartz calibration are well aligned with phase equilibria
and essentially identical to melt inclusion volatile saturation pressures. 相似文献
15.
《Geoforum》2013
The simultaneous but incompatible desires for both “tradition” and “advancement” have produced the “ambiguity of modernity” in the areas of minority nationalities (shaoshu minzu diqu) on China’s southwest frontier. This paper, in accordance, directly addresses the ambiguity of modernity through the investigation of the tea landscape in Yunnan. This essay builds on Aihwa Ong and Stephen Collier’s “global assemblage” framework to analyze the relationship between the “global form” of modernity and the situated assemblages of “ambiguity of modernity” in southwest China. Data are based on ethnographic research in the village of Mangjing, located in Jingmai Mountain, a renowned tea mountain in Yunnan. Most of the villagers in Mangjing are one of the minority nationalities of China, Bulang. I discuss the state-led project in transforming the modern tea plantation for “restoring” a landscape deemed as “ancient tea forest” (guchalin) in Mangjing. In addition, I address Bulang villagers’ and government officials’ multiple responses to the transformation of tea landscapes. I argue that the transformation of tea landscapes has been the practice to turn the “global form” of modernity into the shifting “assemblages” amongst tradition, modernity, science, and nature. The ambiguity of modernity has emerged from the shifting assemblages, providing both the state and Bulang villagers more leeway to symbolically and physically (re)produce meanings for the tea landscapes to meet the contingent market demand for tea. The transformation of tea landscapes, however, has become another process to perpetuate Bulang villagers’ social status of being “low quality” as China’s minority nationalities. 相似文献
16.
《Geoforum》2013
At a time of ongoing economic and social insecurity the capacity to live with difference is under renewed strain. In this context, community outreach organisations and projects of intervention that deal with diversity-related tensions are essential. This paper provides an empirical account of a diversity workshop run by an international organisation that aims to cultivate more peaceful modes of coexistence through attention to the everyday formation of prejudice. The paper has two key concerns. The first is to attend to the techniques employed to facilitate encounters with difference and to unpack the constructions of prejudiced thought. In the context of growing debates around the possibilities and challenges of coordinated contact, the paper engages with work that has articulated alternative ways of responding to difference through an attention to practices of embodied thought. The second concern focuses upon the conditions that make new ways of thinking possible and argues that in order to understand how such organisations might affect positive change, it is vital to understand how such workshops take-place. The paper therefore attends to the role of memory, habit and the working of particular affects such as shame, to open up a discussion about the ways in which workshop exercises might resonate beyond training events. The paper concludes with some reflections upon the implications for policies concerned with behavioural change in the context of developing relations across difference. 相似文献
17.
Angus Cameron 《Geoforum》2012,43(4):741-749
This paper argues that the metaphorical figure of the island plays an important but profoundly ambiguous role in the imagination of social space. The paper argues that ‘utopic’ islands have historically provided a fictional domain of experimentation that has informed the constitution of ‘real’ state spaces. From the 16th to 20th centuries this took the form of an increasingly consolidated and ‘global’ endotopia: a world, exemplified by the ‘political’ map, full of state spaces constituted as interiors. More recently, islands have served a very different metaphoric function, being used to create and legitimise spaces of exteriority – ‘xenospaces’ such as the online worlds of the ‘metaverse’ and the arcane legal/financial spaces of offshore – which in combination constitute an emergent xenotopia. The ‘philosopher’s island’ (Mackay, 2010), therefore, represents a complex and polyvalent spatial form that serves to continuously and expediently redefine the nature of social space. 相似文献
18.
B. J. Smith S. McCabe D. McAllister C. Adamson H. A. Viles J. M. Curran 《Environmental Earth Sciences》2011,63(7-8):1691-1700
Environmental controls on stone decay processes are rapidly changing as a result of changing climate. UKCP09 projections for the 2020s (2010–2039) indicate that over much of the UK seasonality of precipitation will increase. Summer dryness and winter wetness are both set to increase, the latter linked to projected precipitation increases in autumn and spring months. If so, this could increase the time that stone structures remain wet and possibly the depth of moisture penetration, and it appears that building stone in Northern Ireland has already responded through an increased incidence of algal ‘greening’. This paper highlights the need for understanding the effects of climate change through a series of studies of largely sandstone structures. Current and projected climatic trends are therefore considered to have aesthetic, physical and chemical implications that are not currently built into our models of sandstone decay, especially with respect to the role played by deep-seated wetness on sandstone deterioration and decay progression and the feedbacks associated with, for example surface algal growth. In particular, it is proposed that algal biofilms will aid moisture retention and further facilitate moisture and dissolved salt penetration to depth. Thus, whilst the outer surface of stone may continue to experience frequent wetting and drying associated with individual precipitation events, the latter is less likely to be complete, and the interiors of building blocks may only experience wetting/drying in response to seasonal cycling. A possible consequence of deeper salt penetration could be a delay in the onset of surface deterioration, but more rapid and effective retreat once it commences as decay mechanisms ‘tap into a reservoir of deep salt’. 相似文献
19.
Yvonne Küster Bernd Leiss Michael Schramm 《International Journal of Earth Sciences》2010,99(3):505-526
The Kristallbrocken are a characteristic centimetre- to decimetre-sized, laminated halite fabric type occurring in the Stassfurt Formation in the Zechstein Basin. Up to now, the nature of the Kristallbrocken, i.e. if they are relics of fine-grained, polycrystalline halite beds or clasts of ‘single crystal-layers’, as well as the deformation mechanisms of this halite type, were not clear from the literature. Drill core material from the salt deposit Teutschenthal at the southern rim of the Zechstein Basin now allowed investigating less intensely deformed samples for the first time. The deformational behaviour of these Kristallbrocken ranges from brittle to ductile, which is evidenced by fractured Kristallbrocken on the one hand and weakly bent or even folded Kristallbrocken on the other hand. Local X-ray texture measurements demonstrated that the Kristallbrocken are definitely single crystals and that they can be regarded as relics of formerly larger ‘single crystal-layers’ of up to several dm2 in size. The folded Kristallbrocken clearly display by their single grain texture characteristics that their crystal lattice is bent, which was most likely enabled by a kind of flexural-shear folding, and did not develop after deformation from a fine-grained aggregate by recrystallisation. Due to their monocrystallinity, their originally large size, and the solid inclusions forming the internal lamination, the Kristallbrocken have clearly stronger rheological properties than the surrounding fine- to coarse-grained polycrystalline rock salt, and thus also deform by fracturing. 相似文献