Recent changes in heavy metal storage in flood-plain soils of the Lahn River,central Germany     

Charles W. Martin 《Environmental Geology》2009,58(4):803-814

Between 1995 and 2007, the concentrations of Pb and Zn in floodplain soils increased along a 60-km reach of the Lahn River, Germany, suggesting that the storage of some metals in the fluvial system is out of phase with recent declines in the release of metals to the environment. Re-sampling of surface soils to 5 cm along five transects perpendicular to the river indicated that the concentration of Pb increased between 1995 and 2007 along two transects and was statistically unchanged at the other three. The concentration of Zn increased at three of five transects and was statistically unchanged at two transects over the same time period. Between 1995 and 2007, concentrations of Cu were statistically equal along four of five transects and declined at the other transect. The increase in Pb and Zn was greater in a more rural than in a more urbanized reach of the Lahn River. Soil texture and organic matter content had virtually no impact on the concentration of metals. The increase in Pb concentration suggests a lag between the decline in Pb releases to the environment and its movement through the fluvial system. Increased Zn storage may result from the high solubility of the metal and the relative ease with which it moves through the environment. Environmental controls appear to have slowed Cu storage along the Lahn River, but are not yet reflected in Pb and Zn storage.  相似文献   

Quantification of groundwater discharge into lakes using radon-222 as naturally occurring tracer     

Axel Schmidt  Christina E. Stringer  Ulrike Haferkorn  Michael Schubert 《Environmental Geology》2009,56(5):855-863

A case study was carried out with the aim to practically test whether estimates of groundwater discharge rates into dredging lakes can be made via an uncomplicated and straightforward technique using radon-222 as naturally-occurring groundwater tracer. Lake Ammelshainer See, a dredging, seepage lake, approximately 25 km east of Leipzig, Germany, was chosen as the investigation site. In order to evaluate changes in the spatial and temporal radon-222 patterns in the lake during different stages of stratification, sampling campaigns were conducted in April 2007 (well mixed stage) and in May 2007 (thermal stratification stage). Groundwater flow estimates were made using a radon mass balance approach accounting for all radon fluxes into and out of the lake and assuming steady-state conditions with respect to these radon fluxes. Once all positive and negative radon fluxes related to the lake water volume were determined, groundwater discharge was estimated by using the advective radon input and the radon activity concentration of the pore water as key parameters. The results showed that in case of a lake with a size and shape of Lake Ammelshainer See (530,000 m²) reasonable groundwater discharge estimates can be made by collection and analyzing just a few water samples and a few samples from the sediment layer.  相似文献   

A sequence stratigraphic model for the Lower Coal Measures (Upper Carboniferous) of the Ruhr district, north-west Germany   总被引：3，自引：0，他引：3  

Gary Hampson  Harald Stollhofen  & Steve Flint 《Sedimentology》1999,46(6):1199-1231

Upper Carboniferous Coal Measures strata have been interpreted traditionally in terms of cyclothems bounded by marine flooding surfaces (marine bands) and coal seams. Correlation of such cyclothems in an extensive grid of closely spaced coal exploration boreholes provides a robust stratigraphic framework in which to study the Lower Coal Measures (Namurian C–Westphalian A) of the Ruhr district, north-west Germany. Three distinct types of cyclothem are recognized, based on their bounding surfaces and internal facies architecture. (1) Type 1 cyclothems are bounded by marine bands. Each cyclothem comprises a thick (30–80 m), regionally extensive, coarsening-upward delta front succession of interbedded shales, siltstones and sandstones, which may be deeply incised by a major fluvial sandstone complex. The delta front succession is capped by a thin (<1 m), regionally extensive coal seam and an overlying marine band defining the top of the cyclothem. (2) Type 2 cyclothems are bounded by thick (≈1 m), regionally extensive coal seams with few splits. The basal part of a typical cyclothem comprises a thick (15–50 m), widespread, coarsening-upward delta front or lake infill succession consisting of interbedded shales, siltstones and sandstones. Networks of major (>5 km wide, 20–40 m thick), steep-sided, multistorey fluvial sandstone complexes erode deeply into and, in some cases, through these successions and are overlain by the coal seam defining the cyclothem top. (3) Type 3 cyclothems are bounded by regionally extensive coal seam groups, characterized by numerous seam splits on a local (0·1–10 km) scale. Intervening strata vary in thickness (15–60 m) and are characterized by strong local facies variability. Root-penetrated, aggradational floodplain heteroliths pass laterally into single-storey fluvial channel-fill sandstones and coarsening-upward, shallow lake infill successions of interbedded shales, siltstones and sandstones over distances of several hundred metres to a few kilometres. Narrow (<2 km) but thick (20–50 m) multistorey fluvial sandstone complexes are rare, but occur in a few type 3 cyclothems. Several cyclothems are observed to change character from type 1 to type 2 and from type 2 to type 3 up the regional palaeoslope. Consequently, we envisage a model in which each cyclothem type represents a different palaeogeographic belt within the same, idealized delta system, subject to the same allogenic and autogenic controls on facies architecture. Type 1 cyclothems are dominated by deltaic shorelines deposited during a falling stage and lowstand of sea level. Type 2 cyclothems represent the coeval lower delta plain, which was deeply eroded by incised valleys that fed the falling stage and lowstand deltas. Type 3 cyclothems comprise mainly upper delta plain deposits in which the allogenic sea-level control was secondary to autogenic controls on facies architecture. The marine bands, widespread coals and coal seam groups that bound these three cyclothem types record abandonment of the delta system during periods of rapid sea-level rise. The model suggests that the extant cyclothem paradigm does not adequately describe the detailed facies architecture of Lower Coal Measures strata. Instead, these architectures may be better understood within a high-resolution stratigraphic framework incorporating sequence stratigraphic key surfaces, integrated with depositional models derived from analogous Pleistocene–Holocene fluvio-deltaic strata.  相似文献   

Simulation of the effects of geochemical reactions on groundwater quality during planned flooding of the Königstein uranium mine, Saxony, Germany     

Daniel Biehler  W. Eberhard Falck 《Hydrogeology Journal》1999,7(3):284-293

Uranium mining in southeastern Germany resulted in significant environmental risks. Closure of the mines and subsequent rises of water levels may result in heavy-metal and radionuclide-bearing mine waters penetrating aquifers that are used for water supply. While there are certain (geo-)technical constraints on the schedule with which flooding of the mines can proceed, this process must not result in aggravating the problem of metal release. Evaluation of the likely 'natural' geochemical situation of Königstein mine after mining has ceased, and different scenarios for the release of metals indicates that rapid flooding, albeit avoiding unnecessary aeration of the waters, is likely to result in reducing conditions and consequently low U-solubilities.  相似文献   

德国联邦地学研究中心与全德天然气水合物研究     

许红 《海洋地质前沿》2006,22(10):20-21

简要介绍了德国联邦地学研究中心及全德天然气水合物调查研究现状与成果,特别是对“太阳号”在“水合物海脊”和SO177-1航次在中国南海等的科学调查及研究成果进行了介绍。  相似文献   

Synoptic interpretation of seismic reflection and refraction data     

St. Mueller  J. Ansorge  N. Sierro  P. Finckh  D. Emter 《Geophysical Journal International》1987,89(1):345-352

Summary. The structure of the upper lithosphere beneath southern Germany, northern Switzerland and west-central Utah (U.S.A.) has been investigated in detail by various geophysical methods. A synoptic interpretation of travel time and amplitude data obtained in seismic refraction and wide-angle reflection surveys, combined with near-normal incidence reflection observations, now permits the elucidation of the fine structure in a more quantitative and unified manner. With this scheme it is possible to unambiguously identify low-velocity zones and to deduce velocity gradients if reliable amplitude information is included in the inversion process.  相似文献   

Preliminary Archaeomagnetic Results from a Floor Sequence of a Bread Kiln in Lübeck (Germany)     

Schnepp  Elisabeth  Pucher  Rudolf 《Studia Geophysica et Geodaetica》1998,42(1):1-11

A sequence of 25 bread-kiln floors was sampled for archaeomagnetic measurements in a bakehouse in the old town of Lübeck, Germany. Due to archaeological dating this kiln floor sequence has been built up presumably from the late 13 ^th to the 18 ^th century. The primary magnetisation component is carried by magnetite (maghemite) and is very stable. Small viscous magnetisation components could be removed easily. The preliminary results of characteristic remanent magnetisation for 23 of the kiln-floor layers show clearly the trend of the geomagnetic secular variation expected for that time interval. By comparison with French and British master curves, the kiln-floor sequence started around 1425 and lasted until 1775 AD. Presently, confidence circles are relatively large and need refineing by measuring more samples, which have already been collected. Together with ¹⁴ C dating that can be determined from the charcoals found in the lowest layers and thermoluminescence dating of the layers, we expect to obtain, for the first time, a secular variation curve for Northern Germany covering the time interval from 1400 to 1800 years AD.  相似文献   

Village renewal and rural development in the former German Democratic Republic     

Olivia J. Wilson 《GeoJournal》1998,46(3):247-255

This paper analyses the ‘Dorferneuerung’ or village renewal scheme - a key policy for rural development in the new ‘Länder’ of Germany which has been transferred from the old Länder. The contribution that Dorferneuerung can make to rural development is considered, with particular reference to the experience of participating villages in Sachsen-Anhalt. It concludes that Dorferneuerung has contributed much to improving the built environment but little to new job creation. It is indicative of the advantages and disadvantages of reunification for rural development in the new Länder.  相似文献   

The declining importance of agricultural employment in East Germany     

Elke Knappe 《GeoJournal》1998,46(3):243-246

Agriculture has ceased to be the major employer in the rural areas of East Germany. Far-reaching structural change has resulted in a sharp decrease in employment and the mono-structural character of villages has been lost. Unemployment is now a major problem and women are worst affected. New jobs have been created in construction and elsewhere in the tertiary sector but most people who have found new jobs have to commute to the towns or migrate permanently to the urban areas. A north-south contrast has developed because the more developed network of towns in the latter, combined with a relatively good infrastructure, has enabled many villages to survive as viable communities. An example is Fuchshain near Leipzig where employment with the farming company (the former cooperative with 4200 ha of land) has declined but the population has grown through new housing built for commuters. In the north there has been much depopulation and many houses are used as second homes. Either way there is more conflict occurring now within rural communities because of tensions between the employed and the unemployed and between old and new residents. It is therefore important that land use planning should take into account the changed economic and social profiles and measures should be adopted to ensure that the countryside remains visually attractive and socially cohesive. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

德国大陆科学钻探计划的测井成就   总被引：3，自引：2，他引：1  

王祝文  李舟波 《世界地质》1998,17(2):67-72

德国大陆科学钻探计划（ＫＴＢ）经过８年多的努力,钻探了先导孔（ＶＢ）和主孔（ＨＢ）两口举世瞩目的科学钻孔。地球物理测井技术在这个计划中起到了不忽视的作用,本文简要介绍了在德国大陆学科钻探计划（ＫＴＢ）实施过程中,地球物理测井所取得的主要成就。  相似文献