周口坳陷叶鲁断裂带构造特征及其演化   总被引：1，自引：0，他引：1  

白桦  杨明慧  曾鹏  王金秀  黄万国 《现代地质》2010,24(6)

叶鲁断裂带位于华北克拉通南部,是鲁山-舞阳-阜阳-淮南断裂带的重要组成部分,控制着周口坳陷谭庄、舞阳等凹陷的形成与演化。据钻井、地震剖面解释和平衡剖面分析,在秦岭-大别造山带挤压活动的影响下,叶鲁断裂带在晚侏罗世—早白垩世向NNE方向强烈逆冲,主断层面倾角约37°,伸展率可达-22 m/Ma;晚白垩世—古近纪,周口坳陷处于伸展构造环境,该断裂带发生负反转构造作用。通过三角剪切软件模拟了叶鲁断裂带主断层在周参12井区的构造演化过程。模拟显示主断层形成时的总滑动量约为6 100 m,断层传播量为9 150 m,三角剪切角为150°,p/s值为1.5。  相似文献   

Monitoring the development of intertidal habitats on former agricultural land after the managed realignment of coastal defences at Tollesbury, Essex, UK     

Garbutt RA  Reading CJ  Wolters M  Gray AJ  Rothery P 《Marine pollution bulletin》2006,53(1-4):155-164

The managed realignment of coastal defences and subsequent creation of intertidal habitats is one of several 'soft' engineering options that could reduce the costs of maintaining embankments and at the same time deliver environmental benefits. The managed realignment at Tollesbury was one of the first in the UK, undertaken as an experimental test case to improve understanding of the practical techniques and processes involved. Independent studies were undertaken on the development of soils, benthic invertebrates and vegetation within the site in addition to methods of enhancing the process of natural colonisation of saltmarsh plants. Bathymetric and vegetation monitoring were undertaken on the adjacent estuary to determine any breach effect that may be attributed to the realignment. This paper summarises the results from the vegetation, sedimentation and invertebrate monitoring and discusses the implications for other managed realignment schemes in the UK.  相似文献   

The significance of dilution in evaluating possible impacts of wastewater discharges from large cruise ships   总被引：1，自引：0，他引：1  

Loehr LC  Beegle-Krause CJ  George K  McGee CD  Mearns AJ  Atkinson MJ 《Marine pollution bulletin》2006,52(6):681-688

In response to public concerns about discharges from large cruise ships, Alaska's Department of Environmental Conservation (ADEC) sampled numerous effluents in the summer of 2000. The data showed that basic marine sanitation device (MSD) technology for black water (sewage) was not performing as expected. Untreated gray water had high levels of conventional pollutants and surprisingly high levels of bacteria. Both black water and gray water discharges sometimes exceeded state water quality standards for toxicants. The state convened a Science Advisory Panel (the Panel) to evaluate impacts associated with cruise ship wastewater discharges. The effluent data received wide media coverage and increased public concerns. Consequently, legislative decisions were made at the State and Federal level, and regulations were imposed before the Panel completed its evaluation. The Panel demonstrated that following the rapid dilution from moving cruise ships, the effluent data from the Summer of 2000 would not have exceeded water quality standards, and environmental effects were not expected.  相似文献   

Total and labile metals in surface sediments of the tropical river-estuary system of Marabasco (Pacific coast of Mexico): Influence of an iron mine     

Marmolejo-Rodríguez AJ  Prego R  Meyer-Willerer A  Shumilin E  Cobelo-García A 《Marine pollution bulletin》2007,55(10-12):459-468

Marabasco is a tropical river-estuary system comprising the Marabasco river and the Barra de Navidad Lagoon. The river is impacted by the Pe?a Colorada iron mine, which produces 3.5 million tons of pellets per year. Thirteen surface sediment samples were collected in May 2005 (dry season) in order to establish background levels of Al, Cd, Co, Cu, Fe, Ni, Pb, and Zn in the system and to ascertain the potential mobility of metals in the sediments. Analyses were carried out in the fraction finer than 63 microm, and labile metals extracted according the BCR procedure. Certified reference materials were used for validation of methods. Total concentrations of Cd, Co, Cu, Ni, Pb, and Zn were in the range of 0.05-0.34, 6-95, 0.7-31, 9-26, 2-18, and 53-179 mgkg(-1), respectively; Al and Fe ranges of 24-127, and 26-69 mgg(-1) correspondingly. Cadmium was found to be significantly labile in the sediments (20-100%), followed by Co (0-35%), Ni (3-16%) and Zn (0-25%), whereas the labile fraction for Cu, Fe and Pb was almost negligible (<4%). According with the total metal concentrations, background levels and normalised enrichment factors (NEF) of the metals studied, the impact of the Pe?a Colorada iron mine on the Marabasco system is lower than expected when compared with other similar World systems influenced by mining activities.  相似文献   

Physical, chemical and microbiological characterization of the intertidal sediments of Pereque Beach, Guarujá (SP), Brazil     

de Oliveira AJ  Hollnagel HC  Lima Mesquita Hde S  Fontes RF 《Marine pollution bulletin》2007,54(7):921-927

Physical and chemical characteristics of intertidal sediments and their relationships with bacteria and cyanobacteria were analyzed at four stations at Pereque Beach. Granulometric analysis showed that Pereque beach has sediment that is classified as sand. The lowest value of the sediment C/N rates (6.08), mainly due to a higher concentration of organic nitrogen, was found at the northern part of Pereque Beach, where organic matter of marine source was more prominent. In this area, density (9.6x10(6)cells cm(-3)), biomass (1992.04ngC cm(-3)) and activity of bacteria were higher than at the southern end. In contrast, cyanobacteria density varied from 2.0 to 4.0x10(5)cells cm(-3), with biomass and total chlorophyll a of the sediment being higher at the southern part, where there are water input from Pereque River and higher organic matter of continental origin. The variability in the microbial population is discussed in the light of the sediment granulometry, organic matter quality, fresh water inflow and pollution.  相似文献   

Compound response of marine and terrestrial ecosystems to varying climate: pre-anthropogenic perspective from bivalve shell growth increments and tree-rings     

Helama S  Schöne BR  Kirchhefer AJ  Nielsen JK  Rodland DL  Janssen R 《Marine environmental research》2007,63(3):185-199

Annual growth increments were examined from shells of the ocean quahog (Arctica islandica L.) from northwest Norway and from tree-ring samples of the Scots pine (Pinus sylvestris L.) from nearby coastal areas. The reconstructed annual growth increments were used to compare growth variability in marine and terrestrial ecosystems. Spatiotemporal comparison of the growth records showed statistically significant correlation during the 19th century A.D., indicative of ecosystem-independent response to pre-anthropogenic climate variations. Geographical correlation between marine and terrestrial records was only observed at the local scale. Years with particularly low winter or high summer North Atlantic Oscillation (NAO) indices showed the best synchronization of marine and terrestrial growth. Despite strong correlation during historical time, our palaeoecological evidence suggests that marine and terrestrial ecosystems may show dissimilar growth reaction to recently observed positive winter-NAO phases.  相似文献   

查干布拉根银氧化矿堆浸试验研究     

白桦李德成  张洪刚赵志刚 戴利民 《黑龙江国土资源》2006,(6):38-39

查干布拉根银矿是黑龙江省地质勘查局七0三队、七0六队经多年勘查发现的大型银矿床，原生矿由国家控制开采，地表银氧化矿允许该局独立开采，独立选冶。怎样选择一个投资少、见效快，即简便、又适合普通地质队现有人力、财力来承担完成，而且能产生一定经济效益的提银方案成为急待解决的问题。  相似文献   

开展交叉学科研究是技术革新的关键     

伯克.  AJ  胡航标 《国土资源信息化》1997,(5):40-41

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Some challenges of an "upside down" nitrogen budget--science and management in Greenwich Bay, RI (USA)     

DiMilla PA  Nixon SW  Oczkowski AJ  Altabet MA  McKinney RA 《Marine pollution bulletin》2011,62(4):672-680

When nutrients impact estuarine water quality, scientists and managers instinctively focus on quantifying and controlling land-based sources. However, in Greenwich Bay, RI, the estuary opens onto a larger and more intensively fertilized coastal water body (Narragansett Bay). Previous inventories of nitrogen (N) inputs to Greenwich Bay found that N inputs from Narragansett Bay exceeded those from the local watershed, suggesting that recent efforts to reduce local watershed N loads may have little effect on estuarine water quality. We used stable isotopes of N to characterize watershed and Narragansett Bay N sources as well as the composition of primary producers and consumers throughout Greenwich Bay. Results were consistent with previous assessments of the importance of N inputs to Greenwich Bay from Narragansett Bay. As multiple N sources contribute to estuarine water quality, effective management requires attention to individual sources commensurate with overall magnitude, regardless of the political complications that may entail.  相似文献   

Assessment of managed aquifer recharge potential using ensembles of local models     

Smith AJ  Pollock DW 《Ground water》2012,50(1):133-143

A simple quantitative approach for assessing the artificial recharge potential of large regions using spatial ensembles of local models is proposed. The method extends existing qualitative approaches and enables rapid assessments within a programmable environment. Spatial discretization of a water resource region into continuous local domains allows simple local models to be applied independently in each domain using lumped parameters. The ensemble results can be analyzed directly or combined with other quantitative and thematic information and visualized as regional suitability maps. A case study considers the hydraulic potential for surface infiltration across a large water resource region using a published analytic model for basin recharge. The model solution was implemented within a geographic information system and evaluated independently in >21,000 local domains using lumped parameters derived from existing regional datasets. Computer execution times to run the whole ensemble and process the results were in the order of a few minutes. Relevant aspects of the case study results and general conclusions concerning the utility and limitations of the method are discussed.  相似文献