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981.
The Batang Group in the Zhaokalong area not only hosts an important Fe-Cu polymetallic deposit but also reveal important insights for the Late Triassic tectonism in the northern Sanjiang region. In order to delineate the tectonic setting and evolutionary process of the paleo arc-basin system, geochemical studies on the Batang Group strata have been carried out. The results suggest that andesite in the Zhaokalong area mainly belongs to the tholeiite series and is characterized by obvious fractionation of LREE and HREE, enrichment in LILE and depletion in HFSE, and a distinctly elevated δ~(34)SCDT average of 10.5‰. The sandstone is classified as lithic sandstone, which is also characterized by obvious fractionation of LREE and HREE, as well as weak negative Ce and Eu anomalies. The limestone displays positive Eu anomalies, with δ~(13)CPDB ranging from-1.3‰ to 4.4‰ and δ~(18) OSMOW ranging from 14.6‰ to 22.5‰. These results indicate that the andesite has a dual signature of both arc andesite and rift volcanic rocks, whereas the sandstone may be formed in an active continental margin, and the limestone could be deposited in a weak oxidizing shallow sea. The sandstone in the Zhaokalong area represents sedimentation in a platform slope facies, corresponding to the main stage of the Jinshajing oceanic basin subduction during the middle period of Late Triassic. The continental arc volcanic activity resulted from subsequent strengthened subduction, forming the andesite in the North Qiangtang backarc basin. Afterwards, the limestone was formed after the cessation of magmatic activity. The information gleaned from the Batang Group strata helped constrain the evolution of the paleo-Jomda island arc and Jinshajiang oceanic subduction in the Late Triassic.  相似文献   
982.
983.
984.
Fluid migration pathways in the subsurface are heavily influenced by pre‐existing faults. Although studies of active fluid‐escape structures can provide insights into the relationships between faults and fluid flow, they cannot fully constrain the geometry of and controls on the contemporaneous subsurface fluid flow pathways. We use 3D seismic reflection data from offshore NW Australia to map 121 ancient hydrothermal vents, likely related to magmatic activity, and a normal fault array considered to form fluid pathways. The buried vents consist of craters up to 264 m deep, which host a mound of disaggregated sedimentary material up to 518 m thick. There is a correlation between vent alignment and underlying fault traces. Seismic‐stratigraphic observations and fault kinematic analyses reveal that the vents were emplaced on an intra‐Tithonian seabed in response to the explosive release of fluids hosted within the fault array. We speculate that during the Late Jurassic the convex‐upwards morphology of the upper tip‐lines of individual faults acted to channelize ascending fluids and control where fluid expulsion and vent formation occurred. This contribution highlights the usefulness of 3D seismic reflection data to constraining normal fault‐controlled subsurface fluid flow.  相似文献   
985.
Sedimentary basins in NW‐Germany and the Netherlands represent potential targets for shale gas exploration in Europe due to the presence of Cretaceous (Wealden) and Jurassic (Posidonia) marlstones/shales as well as various Carboniferous black shales. In order to assess the regional shale gas prospectivity of this area, a 3D high‐resolution petroleum system model has been compiled and used to reconstruct the source‐rock maturation based on calibrated burial and thermal histories. Different basal heat flow scenarios and accordingly, different high‐resolution scenarios of erosional amount distribution were constructed, incorporating all major uplift events that affected the study area. The model delivers an independent 3D reappraisal of the tectonic and thermal history that controlled the differential geodynamic evolution and provides a high‐resolution image of the maturity distribution and evolution throughout the study area and the different basins. Pressure, temperature and TOC‐dependent gas storage capacity and gas contents of the Posidonia Shale and Wealden were calculated based on experimentally derived Langmuir sorption parameters and newly compiled source‐rock thickness maps indicating shale gas potential of the Lower Saxony Basin, southern Gifhorn Trough and West Netherlands Basin.  相似文献   
986.
The Kyoto Protocol's Clean Development Mechanism (CDM) is a carbon credit trading scheme intended to reduce anthropogenic greenhouse gas emissions and promote ‘sustainable development’. Hundreds of CDM‐sponsored hydroelectric dams have been constructed in southwest China's Yunnan Province, where carbon finance contributes substantial financial incentives to hydropower expansion. This article investigates whether riparian Handai farmers settled near the Madushan hydropower plant on the Chinese section of Red River have experienced positive outcomes from this project's participation in the CDM. I assess how Handai individuals' access to core livelihood assets has been modified following dam completion and probe how the CDM reconfigures scalar relations among the various stakeholders involved in hydropower governance in Yunnan. Though the CDM facilitates hydropower expansion, it fails to produce development that is more sustainable than ‘business as usual’ from a local perspective. Rather, the CDM consolidates hydropower governance in the same way as it unfolded in Yunnan before the province became an active participant in this scheme. The CDM also facilitates a national development campaign fostering specific socio‐economic modernization patterns in China's western provinces.  相似文献   
987.
Within the African context, body shape preferences may be influenced by culture without necessarily taking into consideration health implications. Thus, fatness is culturally associated with beauty, prosperity, and prestige while thinness is perceived as a sign of ill‐health or poverty. Using a cross section of Makola market women, who traditionally are perceived as fat and affluent, our findings revealed that the perception of fatness as a sign of richness and beauty is changing due to women's access to knowledge and information on the health implications of fatness. The challenge for these women however, is adhering to healthy lifestyles despite living sedentary lives in the market place which is a conducive environment for one to become fat. We recommend that qualified professionals should encourage these women through continuous programmes on regenerative health and nutrition aimed at healthy lifestyle behaviour at the market places. The social groups that women belong to should be targeted, trained and equipped with the right information on healthy living so that they can disseminate this information to other members of their networks.  相似文献   
988.
In the North Atlantic the Icelandic, the North Sea, and the Newfoundland cod stocks are currently overexploited. Overexploitation also characterised the Northeast Arctic cod stock, but effective management measures introduced in 1990 and the years thereafter have brought this stock within safe biological limits. The Northeast Arctic cod stock is transboundary and shared between Norway and Russia. As guidelines for a sound management strategy of this cod stock in the future, reference points for management are discussed. As a point of departure, a management strategy which fulfils the objectives for fishery policy stated by Norway is analysed. These objectives, focusing on sustainable harvesting, increased profitability and the role of the fishery as employer of labour in rural districts are fundamental in most of the world's fishery nations.The “optimal” strategy is defined as the one which fulfils these in the best way possible. The natural variations are discussed and the biological and economic yield's dependence upon the rate of exploitation are analysed. The analysis shows that the size of the spawning stock should be no less than 500 000 tonnes and that highest yield is obtained through a rate of exploitation of around 17–30% (equivalent to a fishing mortality of about 0.20–0.40). A spawning stock size of 500 000 tonnes should therefore serve as a “limit reference point” and a fishing mortality of about 0.20–0.40 should serve as a “target reference point” in the management of Northeast Arctic cod.The method described may be applied to other demersal stocks to help establish target and limit reference points in order to conduct a sound management.  相似文献   
989.
Perch (Perca fluviatilis), were sampled from unpolluted and polluted areas in Swedish coastal waters. The level of aromatic/hydrophobic DNA adducts in liver tissue was analyzed using the nucleas P1 version of the32P-post-labeling assay. The level of total adducts measured in the individual fish from polluted areas was between 6 and 22 nmol of adducts/mol of nucleotides, and in the fish from the reference area between 0.2 and 0.6 nmol of adducts/mol of nucleotides.  相似文献   
990.
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