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Raymond Asare Tutu John Kwame Boateng Janice Desire Busingye Edmund Ameyaw 《GeoJournal》2017,82(5):907-921
This exploratory study examines how migrants’ lifestyles are associated with subjective assessment of their health status in a relatively poor urban neighborhood in Accra. For more than half a century, urban centers have been on the receiving end of internal migrants in Ghana with Accra, Kumasi, and Sekondi-Takoradi receiving the lion’s share. However, a lot of migrants end up in poor neighborhoods due to inability to afford relatively costly rents in the better residential areas in the cities. Migrants who live on the margins of society are adversely impacted by poor environmental conditions that make them susceptible to environmentally-induced diseases such as malaria, cholera, and typhoid. While the poverty, health, and place research in Accra, Ghana, have focused on spatial distribution of inequalities in health, burden of sexual ill health, double burden of diseases, environment, wealth and health relationship, as well as income and health connections, there is paucity of research on association between the daily lifestyles of migrants in poor urban neighborhoods and their health status. Specifically on lifestyle and contextual factors, we examine (1) eating and drinking behavior, (2) perception of environmental factors, (3) attitudes and practices during illnesses, and (4) physical activities. Results from Ordinal Logit Regression models suggest that the key predictors of self-rated health status are: (1) socio-demographic elements like length of stay, job type, and religiosity; and (2) eating and drinking behavior—frequency of buying food from food vendors, and (3) social capital. 相似文献
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LIU Xianfan SONG Xiangfeng LU Qiuxi TAO Zhuan LONG Xunrong ZHAO Fufeng 《《地质学报》英文版》2009,83(2):258-265
Three special types of xenoliths have recently been found in an aegirine–augite syenite porphyry in Liuhe, Yunnan, China. Petrographical, petrochemical, electron microprobe, and scanning electron microscopy studies indicate that pure calcite xenocrysts and quartz-bearing topaz pegmatite xenoliths result from the degassing of mantle fluids during their migration, and that black microcrystalline iron-rich silicate-melt xenoliths are the product of the extraction of mantle fluids accompanying degassing and are composed dominantly of quartz, chlorite, and iron-rich columnar and sheet silicate minerals with characteristic minerals, such as native iron, apatite, and zircon. According to the bulk-rock chemical and mineral compositions and crystallization states, the microcrystalline melt xenoliths are not the product of conventional magmatism, and especially the existence of native iron further proves that the xenoliths were mantle fluid materials under reduction or anoxic conditions. The study of the special xenoliths furnishes an important deep-process geochemical background of polymetallic mineralization in different rocks and strata in the study area. 相似文献
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Phlogopite-Amphibole-Pyroxenite Xenoliths in Langao,Shaanxi Province,China:evidence for Mantle Metasomatism 总被引：1，自引：0，他引：1
Phlogopite-amphibole-pyroxenite xenoliths contained in the alkali basic-ultrabasic subvolcanic complex in Langao, Shaanxi
Province, are composed of diopside, Ti-rich pargasite, phlogopite apatite, sphene and ilmenite, which have subsolidus metamorphism-deformation
textures such as triple-points, cataclastic boundaries and kink-bands. Mineral chemical characteristics show that the diposide,
Ti-rich paragasite and phlogopite are derived from the mantle and are the products of mantle metasomatism. Compared with normal
mantle-derived spinel-lherzolites, the xenoliths are enriched in TiO2, Fe2O3, CaO, Na2O and K2O, with apparent depletion in MgO. Chondrite-normalized REE patterns and primordial-mantle normalized trace elements data
show that they are enriched in REE (especially LREE) and incompatible trace elements. The petrographic, mineralogical and
petrochemical characteristics indicate that the xenoliths are metasomatized mantle xenoliths, which offers the evidence for
mantle metasomatism and represents the anomalous mantle beneath the Early Paleozoic rift in northern Daba Mountains. The agents
of mantle metasomatism are probably derived from the rising of mantle hot plumes. The processes of metasomatism varied from
limited-range fluid metasomatism in deep mantle (>90 km) to pervasive metasomatism of silicate melt.
This project was financially supported by the National Natural Science Foundation of China (No. 49402035). 相似文献
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《Journal of Structural Geology》1999,21(8-9):1011-1018
In fold-and-thrust belts that experienced both pre-orogenic and post-orogenic extension, it may be difficult to establish whether observed normal faults pre-dated, post-dated, or were synchronous with thrusting. Geometrical structural patterns may be insufficient to constrain the relative chronology of extensional and contractional deformations. The systematic use of kinematic criteria makes it possible to unequivocally define the timing relationships of reverse and normal fault development, and hence to correctly unravel complex structural evolutions. Kinematic analysis in the southernmost Umbria–Marche Apennines of Italy, where both normal and thrust faults are present, revealed a history of repeated tectonic inversion, characterised by two distinct stages of extension separated by an episode of folding and thrusting. Structural overprinting relationships observed at thrust–normal fault intersections were useful for: (i) removing sequentially younger deformations; and hence (ii) separating and quantifying the effects of orogenic contraction from those of both pre-orogenic and post-orogenic extension. 相似文献
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H. R. J. Davies 《GeoJournal》1994,33(4):387-392
Islands at strategic points have often become the core of a modern city, or have been developed as historic heritage sites. This has been especially true when the settlers have been strangers in the land. This paper examines why such a situation has not occurred with Tuti Island at the confluence of the White and Blue Niles in the centre of Sudan's Three Towns capital, even though the first permanent inhabitants at the confluence were strangers and chose Tuti Island for their first settlement. The paper questions whether Tuti can survive as a green eye in its present form with the increasing pressures from the urban areas surrounding it. 相似文献
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In-situ Moissanite in Dunite: Deep Mantle Origin of Mantle Peridotite in Luobusa Ophiolite, Tibet 总被引：1，自引：0，他引：1
We report the discovery of an in-situ natural moissanite as an inclusion in the Cr-spinel from the dunite envelope of a chromitite deposit in Luobusa ophiolite, Tibet. The moissanite occurs as a twin crystal interpenetrated by two quadrilateral signal crystals with sizes of 17 μm× 10 μm and 20 μm× 7 μm, respectively. The moissanite is green with parallel extinction. The absorption peaks in its Raman spectra are at 967-971 cm-1, 787-788 cm-1, and 766 cm-1. The absorption peaks in the infrared spectra are at 696 cm-1, 767 cm-1, 1450 cm-1, and 1551 cm-1, which are distinctly different from the peaks for synthetic silicon carbide. Moissanites have been documented to form in ultra-high pressure, high temperature, and extremely low fO2 environments and their 13C-depleted compositions indicate a lower mantle origin. Combined with previous studies about other ultra-high pressure and highly reduced minerals in Luobusa ophiolite, the in-situ natural moissanite we found indicates a deep mantle origin of some materials in the mantle sequence of Luobusa ophiolite. Further, we proposed a transformation model to explain the transfer process of UHP materials from the deep mantle to ophiolite sequence and then to the supra-subduction zone environment. Interactions between the crown of the mantle plume and mid-ocean ridge are suggested to be the dominant mechanism. 相似文献
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This study defines the source area, sub-aerial weathering, and sedimentary cycle level, as well as heavy metal content and origin, of the Çoruh River bed sediments. The studied sediments are geochemically classified as litharenite based on the ratio of the major element contents. Relative to the Upper Continental Crust (UCC), trace elements Rb, Sr, Ba, Th, U, Zr, Hf, Y, Nb, and Pb are generally depleted; Co, Ni, Cu, Sc, and V are generally enriched; and Au is depleted in some places and enriched in other places. The rare earth element (REE) distributions of the samples exhibit a trend similar to that of the upper continental crust (UCC); however, low to moderate depletion occurs in the bed sediments in UCC. The analyzed samples exhibit low Chemical Index of Alteration (CIA) values, Plagioclase Index of Alteration (PIA) values (<50), CIA/WIP (Weathering Index ratios <1), and substantially high Index of Compositional Variability values (ICV) (>1). Thus, the samples are not chemically mature and are mainly derived from non-altered sources and were exposed the simple cycling history. REEs are depleted in the river bed sediments, unlike the world river average silt, world river average clay, and suspended sediment in world rivers. Minor enrichment of Zn, Sn, and Sc contents, low-to-moderate enrichment of Cu content, very severe enrichment of as content, and extremely severe enrichment of Ni content of the analyzed samples are observed. Consequently, stream bed sediments are derived from intermediate sources close to mid-continental crust rather than felsic sources Low-to-moderate degrees of chemical weathering of these sediments indicate increased tectonic activity, increased erosion, and rapid sedimentation in semiarid to arid conditions in the source regions over time. Thus, the sediments are chemically immature. These sediments are exposed to lithogenic and anthropogenic contamination. 相似文献
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Please refer to the attachment(s) for more details 相似文献
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M. M. Pevzner D. O. Gertsev P. I. Fedorov F. A. Romanenko Yu. V. Kushcheva 《Lithology and Mineral Resources》2017,52(1):20-50
The study of lavas and pyroclastics from Anyui Volcano made it possible to reconstruct succession of its eruption events. The age of the eruption is estimated by isotopic methods to be 0.248 ± 0.030 Ma. It is established that the last episode of volcanic activity in northeastern Russia occurred 0.2?0.5 Ma ago (in its continental part, 0.2?0.3 Ma ago). This episode is chronologically close to the last peak in activation of volcanism in the Arctic and Subarctic regions. The absence of features indicating glacial influence on lavas from Anyui Volcano provides grounds for an assumption that no significant glaciations took place in the continental areas of western Chukotka during the last 250 ka. 相似文献
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This paper deciphers the late stress systems involved in the development of kink bands in the perspective of thrust regime.
In kink bands, the correlation coefficient for α–β plots is positive near thrusts and negative away from thrusts. The plots show nearly linear relationship near thrusts and
non-linear relationship away from thrusts. The rotation was prominent mechanism of kink band formation near thrusts and rotation
coupled with shearing, along the kink planes away from thrusts. Along thrusts σ
1 is horizontal E–W trend and it rotates to horizontal N–S trend away from the thrust. The proposed model establishes that
(1) the shearing along kink planes led to angular relationship, β < α and (2) the kink planes of conjugate kinks could be used for paleostress analysis even in those cases where shearing along
these planes has occurred. 相似文献
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GU Shangyi WAN Guojiang MAO Jianquan 《中国地球化学学报》2007,26(4):434-438
The Pinxiang weathering profile is well developed on Early Triassic dacite lavas of the Baisi Formation. At the top of the profile is developed a red clay zone which is characterized mineralogically by kaolinite, iron oxide minerals, quartz, and a small amount of illite, montmorillonite and vermiculite. In going downwards the red clay zone gives way to a saprolite zone in which plagioclase pseudomorphs have been well preserved although replaced by kaolinite. Beneath the saprolite zone is the saprock zone characterized by less weathering for dacite. At the bottom of the weathering profile is the parent material, dacite, which is composed mainly of plagioclase, quartz, K-feldspar and biotite which have been largely altered into chlorite owing to submarine extrusion of dacite lavas. Some layers in the weathering profile show obvious sodium enrichment and potassium depletion relative to others. In the Al2O3-(CaO* Na2O)-K2O triangular diagram, the weathering trends of these layers in the middle stage are remarkably deviated from normal ones. Both mineralogy and micro-morphology of these layers indicate such deviation resulted from sodic metasomatism of orthoclase. 相似文献
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Richard Mbatu 《GeoJournal》2010,75(5):443-458
This paper characterizes changes in land use and forest cover in southern Cameroon. In doing so, we use remotely sensed data
to define the rates and area of forest loss and cover change in two reference areas over a period of 16 years (from 1984 to
2000)—the Buea-Limbe area in the southwest province and the Bertoua area in the east province. We relate socio-economic data
of these study areas with results from the empirical spatial analysis to explain causes of deforestation. A second set of
explanations, which we call the theoretical perspective, attributes deforestation in southern Cameroon to the intricacies
of modernization, world-systems, and neo-Malthusian theories. 相似文献
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Becoming “Hispanic” in the “New South”: Central American immigrants’ racialization experiences in Atlanta,GA, USA 总被引：1，自引：0，他引：1
Robert A. Yarbrough 《GeoJournal》2010,75(3):249-260
For many migrants from Latin America, “Hispanic/Latino(a)” is an identity that they encounter in the United States with which
they were unfamiliar in their home countries and must negotiate in their everyday lives in a new context. Specifically, immigrants
from Central America are unlikely to see themselves as “Hispanic” or “Latino(a)” prior to living in the United States, more
often identifying with their home country, city, town, village, or neighborhood. This paper draws on racialization theory
and twenty-seven in-depth interviews with Central American immigrants in Atlanta, GA to examine this process of identity negotiation
across the traditionally black/white racialized landscapes of a “New South” city. Interview participants adopt a racialized
Hispanic identity through a complex process involving the interplay between how they think of themselves and their perceptions
of how native-born Atlantans view them. The interview analysis presented herein demonstrates that although Central American
immigrants actively negotiate a Hispanic racialized moniker, they do so within an urban context dominated by native-born residents
whose racialized assumptions lump Spanish-speaking, brown skinned individuals into a monolithic “Mexican” category. Thus the
ways in which racialized difference is constructed in contemporary Atlanta for recent Central American immigrants is very
much bound up in such false presumptions of national identity and cultural group belonging. 相似文献
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Godwin Masuka 《Geoforum》2012,43(3):573-584
The paper examines the relations between farmers and The Cotton Company of Zimbabwe (COTTCO) in Rushinga district of Zimbabwe. Based on interviews with farmers and secondary data, it examines the practice of side marketing of contracted seed cotton. While a large body of literature has discussed the social and economic effects of contract farming on farmers, there are less critical studies on side marketing of crops by farmers in unstable economic and political environment such as Zimbabwe. The paper demonstrates that farmers taking advantage of the macroeconomic environment in Zimbabwe violated contracts by selling seed cotton to other buyers. In the process, farmers renegotiated the meaning of the contract and appealed to market rationality embedded in the neo-liberal ideology. For these farmers, side marketing was part of a survival strategy, albeit in imperfect markets and a difficult economic environment. Nonetheless, side marketing of seed cotton strained relations between farmers and COTTCO. The paper shows the tensions in contracts that require regulation by the state and the neo-liberal ideology that promote free markets and argue against strong regulation. 相似文献