Phosphorus retention in calcareous soils and the effect of organic matter on its mobility   总被引：7，自引：0，他引：7  

Ray von Wandruszka 《Geochemical transactions》2006,7(1):6-8

A survey of the interactions between phosphorus (P) species and the components of calcareous soils shows that both surface reactions and precipitation take place, especially in the presence of calcite and limestone. The principal products of these reactions are dicalcium phosphate and octacalcium phosphate, which may interconvert after formation. The role of calcium carbonate in P retention by calcareous soils is, however, significant only at relatively high P concentrations – non-carbonate clays play a more important part at lower concentrations. In the presence of iron oxide particles, occlusion of P frequently occurs in these bodies, especially with forms of the element that are pedogenic in origin. Progressive mineralization and immobilization, often biological in nature, are generally observed when P is added as a fertilizer.  相似文献   

The political geography of religion: historical state-church relations in Europe and recent challenges     

Hans Knippenberg 《GeoJournal》2006,67(4):253-265

Historical processes of state formation and nation building are crucial for an understanding of the geography of religions and churches in Europe. Each country has developed its own model of state-church relations, giving rise to a ‘bewildering variety’ as Grace Davie aptly remarks. The aim of this paper is to bring some order to this variety by developing a framework for the comparative study of church-state relations based on Stein Rokkan’s famous conceptual map and recent extensions of it to Central and Eastern Europe by John Madeley. According to that framework Europe has been divided into three mono-confessional (Roman Catholic, Lutheran, and Eastern Orthodox) blocs and two multi-confessional culture belts from Northwest to Southeast, and from Northeast to Southeast. This historical pattern has been challenged by secularisation, which started with the Enlightenment and the French Revolution (Western Europe) and the Russian Revolution (Eastern Europe until the velvet revolutions of 1989/1991) and then became widespread after the ‘cultural revolutions’ of the 1960s. A second challenge has to do with globalisation and its consequences, such as massive immigration and the rise of immigrant religions, and in general deterritorialisation, which means the disembeddedness of religion from its national territory. A third challenge concerns reterritorialisation at other (supranational, regional, transnational, and local) scales, of which the new territorial order of the European Union seems to be the most important. Finally, this paper serves as an introduction to the case studies on church-state relations in this special issue.  相似文献   

Crustal structure across the Grand Banks–Newfoundland Basin Continental Margin – II. Results from a seismic reflection profile     

K. W. Helen Lau  Keith E. Louden  Sharon Deemer  Jeremy Hall  John R. Hopper  Brian E. Tucholke  W. Steven Holbrook  Hans Christian Larsen † 《Geophysical Journal International》2006,167(1):157-170

New multichannel seismic reflection data were collected over a 565 km transect covering the non-volcanic rifted margin of the central eastern Grand Banks and the Newfoundland Basin in the northwestern Atlantic. Three major crustal zones are interpreted from west to east over the seaward 350 km of the profile: (1) continental crust; (2) transitional basement and (3) oceanic crust. Continental crust thins over a wide zone (∼160 km) by forming a large rift basin (Carson Basin) and seaward fault block, together with a series of smaller fault blocks eastwards beneath the Salar and Newfoundland basins. Analysis of selected previous reflection profiles (Lithoprobe 85-4, 85-2 and Conrad NB-1) indicates that prominent landward-dipping reflections observed under the continental slope are a regional phenomenon. They define the landward edge of a deep serpentinized mantle layer, which underlies both extended continental crust and transitional basement. The 80-km-wide transitional basement is defined landwards by a basement high that may consist of serpentinized peridotite and seawards by a pair of basement highs of unknown crustal origin. Flat and unreflective transitional basement most likely is exhumed, serpentinized mantle, although our results do not exclude the possibility of anomalously thinned oceanic crust. A Moho reflection below interpreted oceanic crust is first observed landwards of magnetic anomaly M4, 230 km from the shelf break. Extrapolation of ages from chron M0 to the edge of interpreted oceanic crust suggests that the onset of seafloor spreading was ∼138 Ma (Valanginian) in the south (southern Newfoundland Basin) to ∼125 Ma (Barremian–Aptian boundary) in the north (Flemish Cap), comparable to those proposed for the conjugate margins.  相似文献   

The changing relationship between state and church/religion in the Netherlands     

Hans Knippenberg 《GeoJournal》2006,67(4):317-330

The Netherlands is part of the historic Northwest-Southeast multi-confessional culture belt according to the comparative framework of church-state relations in Europe as recently developed by Madeley on the basis of Rokkan’s conceptual map. The aim of this paper is to describe the development of the church-state relations in the Netherlands within this historic framework of state-formation and nation-building, and to interpret recent challenges of its historic state-church model, such as secularisation, the rise of immigrant religions, and general ‘de- and re-territorialisation’ tendencies. The Netherlands developed from a relatively very tolerant polity dominated by the Calvinist Church to a ‘pillarised’ society, in which the Rome-Reformation divide (which also had a strong geographical dimension) was institutionalised in the political system. After the 1960s, very strong secularisation put this ‘pillarised’ system under severe pressure, but the remnants of this system offered a favourable opportunity structure for religious newcomers (Muslims in particular), who could establish their mosques and Muslim schools relatively easily. However, while the main Protestant churches, and even Catholic and Protestant political parties have merged, failing integration of these newcomers in Dutch society and terrorist attacks at the global level as well as in the Netherlands encouraged a new divide between Muslims and non-Muslims. The metropolitan areas in particular became the scene of this new divide.  相似文献   

Daily Air Temperature and Pressure Series for Stockholm (1756–1998)     

Anders Moberg  Hans Bergström  Josefin Ruiz Krigsman  Ola Svanered 《Climatic change》2002,53(1-3):171-212

Daily meteorological observations have been made at the old astronomical observatory in Stockholm since 1754. Complete daily mean series of air temperature and sea level pressure are reconstructed from the observational data for 1756–1998. The temperature and pressure series arereconstructed and homogenized with the aid of metadata, statistical tests and comparisons with data from other stations. Comparisons with independently reconstructed daily series for nearby Uppsala (1722–1998) show that the quality of thedaily Stockholm data is good, although the reliability is lower before the mid-19th century. The daily temperature data show that the colder winter mean temperatures of the late 18th to early 19th centuries were connected with a particularly high frequency of very cold winter days. The warmer summers of the same period are more connected with a general shift of the temperature distribution towards higher temperatures than in the late 20th century.  相似文献   

Understanding Perturbation on the Simplex: A Simple Method to Better Visualize and Interpret Compositional Data in Ternary Diagrams     

Hilmar von Eynatten  Vera Pawlowsky-Glahn  Juan José Egozcue 《Mathematical Geology》2002,34(3):249-257

Perturbation is an operation defined on the simplex and can be used for centering compositional data in a ternary diagram, applying objective criteria. Because a straight line in the original diagram is still astraight line in the perturbed diagram, gridlines or compositional fields defined by straight lines can easily be included in the operation. Simultaneous perturbation of data, gridlines, and/or compositional fields is shown to improve both visualization and graphical interpretation of compositions in ternary diagrams. This is illustrated by some examples using simulated as well as real data.  相似文献   

Origin of the northern Indus Fan and Murray Ridge, Northern Arabian Sea: interpretation from seismic and magnetic imaging     

Christoph Gaedicke  Hans-Ulrich Schlüter  Hans Albert Roeser  Alexander Prexl  Bernd Schreckenberger  Heinrich Meyer  Christian Reichert  Peter Clift  Shahid Amjad 《Tectonophysics》2002,355(1-4)

The nature and origin of the sediments and crust of the Murray Ridge System and northern Indus Fan are discussed. The uppermost unit consists of Middle Miocene to recent channel–levee complexes typical of submarine fans. This unit is underlain by a second unit composed of hemipelagic to pelagic sediments deposited during the drift phase after the break-up of India–Seychelles–Africa. A predrift sequence of assumed Mesozoic age occurring only as observed above basement ridges is composed of highly consolidated rocks. Different types of the acoustic basement were detected, which reflection seismic pattern, magnetic anomalies and gravity field modeling indicate to be of continental character. The continental crust is extremely thinned in the northern Indus Fan, lacking a typical block-faulted structure. The Indian continent–ocean transition is marked on single MCS profiles by sequences of seaward-dipping reflectors (SDR). In the northwestern Arabian Sea, the Indian plate margin is characterized by several phases of volcanism and deformation revealed from interpretation of multichannel seismic profiles and magnetic anomalies. From this study, thinned continental crust spreads between the northern Murray Ridge System and India underneath the northern Indus Fan.  相似文献   

Geochemistry and sequence stratigraphy of regional Upper Cretaceous limestone units, offshore eastern Canada   总被引：1，自引：0，他引：1  

Hans J.B.W. Wielens  R. Andrew MacRae  John Shimeld 《Organic Geochemistry》2002,33(12)

Hydrocarbons occur in two regional, Upper Cretaceous limestone units—the Turonian-Coniacian Petrel Member, and the Santonian-Maastrichtian Wyandot Formation. The units form important seismic markers beneath the Scotian Shelf and the Grand Banks of Eastern Canada. They mainly consist of bioturbated chalk and minor amounts of calcareous mudstone. A search for source rock using the Δ log R technique showed intervals with source potential, but testing of core and cuttings by Rock-Eval analysis showed no source potential. Three issues are the main cause for the inconsistency: (1) unconsolidated shales that likely included organic material were lost during sample washing; (2) severe contamination by mud additives; and (3) presence of gas. The organic matter found on the shelf has been strongly oxidised, but the distal facies of these limestone units and condensed shale units above and below may yet have potential to form source rock, beyond the studied areas.  相似文献   

The fall and rise of metropolitan government in Copenhagen     

Hans Thor Andersen  Frank Hansen  John Jørgensen 《GeoJournal》2002,58(1):43-52

In this paper it is argued that the re-establishment of a metropolitan government in the Greater Copenhagen Area in 2000 (Greater Copenhagen Authority) is not to be seen as a return to the kind of regional, coordinative authority (Greater Copenhagen Council) that was abolished in the Thatcherite climate of the 1980s. Throughout the 1980s and 1990s new forms of urban governance, entrepreneurialism and a higher national priority to the capital region were introduced, which changed the conditions under which the new metropolitan government is operating. This `contextualization' of the analysis of the two generations of metropolitan government points to the fact that typologies of metropolitan government, such as the one put forward by Sharpe (1995), often lacks analytical cogency. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Water solubility in orthopyroxene   总被引：7，自引：0，他引：7  

Markus Rauch  Hans Keppler 《Contributions to Mineralogy and Petrology》2002,143(5):525-536

The solubility of water in pure enstatite was measured on samples synthesized at 1,100 °C and pressures to 100 kbar. Enstatite crystals were grown under water-saturated conditions from a stoichiometric mixture of high-purity SiO₂ and Mg(OH)₂. Water contents were calculated from polarized FTIR spectra measured on oriented single crystals. The water solubility in orthoenstatite increases with pressure to 867ᆷ ppm H₂O by weight at 75 kbar. At 100 kbar, in the stability field of high-clinoenstatite, a water solubility of 714ᆷ ppm was observed. The water solubility in enstatite at 1,100 °C can be described by the equation c_H2O=Af_H2O exp(-P(V/RT), where f_H2O is water fugacity, A=0.0204 ppm/bar and (V=12.3 cm³/mol. The infrared spectra of the hydrous enstatite crystals show a sharp, intense band at 3,363 cm^-1 and a broad, weaker band at 3,064 cm^-1. Both bands are strongly polarized parallel c. Most likely, pairs of protons attached to non-bridging oxygen atoms substitute for Mg²⁺. In order to investigate the effect of chemical impurities on water solubility in enstatite, an additional series of experiments was carried out with gels doped with Al, B, or Li as starting material. Whereas, the presence of Li and B had no detectable effect on water solubility, the addition of about 1 wt% Al₂O₃ increased water solubility in enstatite from 199 to 1,100 ppm at 1,100°C and 15 kbar. In the infrared spectra of these aluminous samples, additional bands occur in the range from 3,450 to 3,650 cm^-1. Similar bands are also observed in natural, aluminous orthopyroxenes and are most likely caused by protons coupled with Al according to the substitution of Al³⁺+H⁺ for Si⁴⁺. A series of hydrous annealing experiments on a natural, gem-quality aluminous enstatite from Tanzania yielded water solubilities generally consistent with the results from the synthetic model systems. The results presented here imply that pure enstatite has a similar storage capacity for water as olivine; however, aluminous orthopyroxenes in the mantle may dissolve much larger amounts of water comparable with the entire mass of the present hydrosphere. Moreover, the mechanism of aluminum substitution in orthopyroxenes, i.e., the distribution of Al between tetrahedral and octahedral sites, may be a potential probe of water fugacity.  相似文献