Cambrian sedimentary dykes in the Proterozoic basement of the Västervik area (southeast Sweden): episodic formation inferred from macro- and microfabrics     

Nadine Friese  Axel Vollbrecht  Bernd Leiss  Olaf Jacke 《International Journal of Earth Sciences》2011,100(4):741-752

Fabrics of Cambrian sedimentary dykes formed in Proterozoic granites of the Västervik area (Southeast Sweden) evidence repeated opening/filling and mineralisation/cementation events under varying conditions. Diagnostic features include (1) wall-parallel boundaries between epiclastic fillings and (2) early formed dyke sediments that appear as lithoclasts in subsequently formed sedimentary fillings. The psammitic components mostly consist of well-rounded quartz grains related to a coastal environment and fragments from the granitic host rock. Platy calcitic fragments embedded in the epiclastic matrix originally formed as microveins within already-lithified dyke sediments and the adjacent host rock. Convex downward-pointing, internal sagging structures, together with the preferred orientation of compositional boundaries and long axes of grains/rock fragments parallel to the dyke walls, are interpreted as the result of suction-controlled flow of unconsolidated fillings during episodes of downward dyke growth. Pressure solution of quartz grains are evidence of extensional phases with dyke propagation that were interrupted by phases of horizontal compression normal to the dyke walls. The N–S and NE–SW striking sedimentary dykes formed by opening of a pre-existing joint set during NW–SE oriented rifting during the Cambrian.  相似文献   

Stakeholders’ expectations towards a proposed marine protected area: A multi-criteria analysis of MPA performance criteria     

Nadine Heck  Philip Dearden  Adrian McDonald 《Ocean & Coastal Management》2011,54(9):687-695

In order to enable effective management of marine protected areas (MPAs), desired MPA achievements need to be identified as early as possible for the development of relevant and clear management goals, objectives and conservation targets. As the definition of MPA success is a social construct, the involvement of multiple groups in this process including government agencies, stakeholders, and other interested parties is increasingly advocated. This study investigates diverse groups’ opinions on the performance of a proposed National Marine Conservation Area (NMCA) on the West coast of Canada prior to its establishment. In order to analyse and quantify the importance of MPA performance criteria among multiple stakeholder groups, the Analytical Hierarchy Process (AHP) is applied. Findings reveal that marine stakeholder groups have distinct preferences for future MPA performance. Most differences are obvious between user and non-user groups. The study also finds that respondents’ characteristics other than stakeholder groups affiliations influence expectations towards the proposed MPA including livelihood dependency on the marine environment, amount of time spent in the area, and engagement in fishing activities.  相似文献   

预料之外的安第斯地震     

韩立波 《国际地震动态》2011,(10):12-14

沿南美安第斯山脉西缘的俯冲带边界预期会发生大地震。而沿东边界的地表运动测量表明,曾预期不会发生大地震的安第斯山脉东缘也具有发生同等规模大地震的潜在可能。  相似文献   

Style for the Zeitgeist: The Stealthy Revival of Historicist Housing Since the Late 1960s     

Nadine Dostrovsky  Richard Harris 《The Professional geographer》2013,65(3):314-332

A revival has occurred in the use of historical architectural styles for modern suburban houses but this has attracted little attention from journalists and academics. Those who have noted it disagree about when it began and gathered momentum. Newspaper and trade journal evidence for Canadian cities indicates that the revival began in the late 1960s; that it has reached market saturation; and that Victorian and neo-classical styles became dominant after 1980. Coinciding with the beginnings of inner-city gentrification, the historicist revival in suburban dwellings preceded the recent interest in neotraditional urban design. Not a fringe taste, it says something about the zeitgeist.  相似文献   

Tweet Me Your Talk: Geographical Learning and Knowledge Production 2.0   总被引：1，自引：0，他引：1  

Nadine Schuurman 《The Professional geographer》2013,65(3):369-377

We are in a Gutenberg moment in which we are migrating from book reading to Internet browsing. We are subtly shifting to more ephemeral, summary methods of learning and producing knowledge, shaped by how we consume information on the Web. Thus, a strong determinant of learning might be the very technology that hosts the information, such that technology is both the arbiter of our understanding of the world and how we come to gain that understanding. Based on recent evidence that the Internet is reshaping our learning processes, I argue that geographical knowledge production and translation are not so much products of individualism but rather shaped by rapidly changing work styles that favor concise and highly accessible methods of academic production. I offer examples of changes in journal formats, academic social networking, and academic reviewing to reveal that we are catering to shorter attention spans that prefer to browse.  相似文献   

Storage,mixing, and fluxes of water in the critical zone across northern environments inferred by stable isotopes of soil water          下载免费PDF全文

Matthias Sprenger  Doerthe Tetzlaff  Jim Buttle  Sean K. Carey  James P. McNamara  Hjalmar Laudon  Nadine J. Shatilla  Chris Soulsby 《水文研究》2018,32(12):1720-1737

Quantifying soil water storage, mixing, and release via recharge, transpiration, and evaporation is essential for a better understanding of critical zone processes. Here, we integrate stable isotope (²H and ¹⁸O of soil water, precipitation, and groundwater) and hydrometric (soil moisture) data from 5 long‐term experimental catchments along a hydroclimatic gradient across northern latitudes: Dry Creek (USA), Bruntland Burn (Scotland), Dorset (Canada), Krycklan (Sweden), and Wolf Creek (Canada). Within each catchment, 6 to 11 isotope sampling campaigns occurred at 2 to 4 sampling locations over at least 1 year. Analysis for ²H and ¹⁸O in the bulk pore water was done for >2,500 soil samples either by cryogenic extraction (Dry Creek) or by direct equilibration (other sites). The results showed a similar general pattern that soil water isotope variability reflected the seasonality of the precipitation input signal. However, pronounced differences among sampling locations occurred regarding the isotopic fractionation due to evaporation. We found that antecedent precipitation volumes mainly governed the fractionation signal, temperature and evaporation rates were of secondary importance, and soil moisture played only a minor role in the variability of soil water evaporation fractionation across the hydroclimatic gradient. We further observed that soil waters beneath conifer trees were more fractionated than beneath heather shrubs or red oak trees, indicating higher soil evaporation rates in coniferous forests. Sampling locations closer to streams were more damped and depleted in their stable isotopic composition than hillslope sites, revealing increased subsurface mixing towards the saturated zone and a preferential recharge of winter precipitation. Bulk soil waters generally comprised a high share of waters older than 14 days, which indicates that the water in soil pores are usually not fully replaced by recent infiltration events. The presented stable isotope data of soil water were, thus, a useful tool to track the spatial variability of water fluxes within and from the critical zone. Such data provide invaluable information to improve the representation of critical zone processes in spatially distributed hydrological models.  相似文献   

Ontology-Based Metadata   总被引：4，自引：0，他引：4  

Nadine Schuurman  Agnieszka Leszczynski 《Transactions in GIS》2006,10(5):709-726

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Assessing the concentration,speciation, and toxicity of dissolved metals during mixing of acid-mine drainage and ambient river water downstream of the Elizabeth Copper Mine,Vermont, USA     

Laurie S. Balistrieri  Robert R. Seal II  Nadine M. Piatak  Barbara Paul 《Applied Geochemistry》2007

The authors determine the composition of a river that is impacted by acid-mine drainage, evaluate dominant physical and geochemical processes controlling the composition, and assess dissolved metal speciation and toxicity using a combination of laboratory, field and modeling studies. Values of pH increase from 3.3 to 7.6 and the sum of dissolved base metal (Cd + Co + Cu + Ni + Pb + Zn) concentrations decreases from 6270 to 100 μg/L in the dynamic mixing and reaction zone that is downstream of the river’s confluence with acid-mine drainage. Mixing diagrams and PHREEQC calculations indicate that mixing and dilution affect the concentrations of all dissolved elements in the reach, and are the dominant processes controlling dissolved Ca, K, Li, Mn and SO₄ concentrations. Additionally, dissolved Al and Fe concentrations decrease due to mineral precipitation (gibbsite, schwertmannite and ferrihydrite), whereas dissolved concentrations of Cd, Co, Cu, Ni, Pb and Zn decrease due to adsorption onto newly formed Fe precipitates.  相似文献   

Numerical quantification of sources and phase partitioning of chemical species in cloud: application to wintertime anthropogenic air masses at the Puy de Dôme station     

Maud Leriche  R. Lyana Curier  Laurent Deguillaume  Dimitri Caro  Karine Sellegri  Nadine Chaumerliac 《Journal of Atmospheric Chemistry》2007,57(3):281-297

The Model of Multiphase Cloud Chemistry M2C2 has recently been extended to account for nucleation scavenging of aerosol particles in the cloud water chemical composition. This extended version has been applied to multiphase measurements available at the Puy de Dôme station for typical wintertime anthropogenic air masses. The simulated ion concentrations in cloud water are in reasonable agreement with the experimental data. The analysis of the sources of the chemical species in cloud water shows an important contribution from nucleation scavenging of particles which prevails for nitrate, sulphate and ammonium. Moreover, the simulation shows that iron, which comes only from the dissolution of aerosol particles in cloud water, has a significant contribution in the hydroxyl radical production. Finally, the simulated phase partitioning of chemical species in cloud are compared with measurements. Numerical results show an underestimation of interstitial particulate phase fraction with respect to the measurements, which could be due to an overestimation of activated mass by the model. However, the simulated number scavenging efficiency of particles agrees well with the measured value of 40% of total number of aerosol particles activated in cloud droplets. Concerning the origin of chemical species in cloud water, the model reproduces quite well the contribution of gas and aerosol scavenging estimated from measurements. In addition, the simulation provides the contribution of in-cloud chemical reactivity to cloud water concentrations.  相似文献   

A novel probe for point injections in groundwater monitoring wells     

Fahrmeier  Nikolai  Goeppert  Nadine  Goldscheider  Nico 《Hydrogeology Journal》2022,30(3):1021-1029

Hydrogeology Journal - Groundwater monitoring wells or boreholes often show complex flow behaviors that are essential to understand for the characterization of aquifer systems. In karst or...  相似文献