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The Kupferschiefer, a thin (<4 m) bed of marine bituminous marl of Upper Permian (Zechstein) age, occurs over a large area of north-central Europe and has, in certain areas, been exploited for silver and some base metals, notably copper, since medieval times. It has been regarded as the type example of a shale-hosted, strata-bound sulfide deposit and theories regarding the origins of Kupferschiefer mineralization have exerted considerable influence on theories of ore genesis. The Kupferschiefer sediments were deposited following a rapid marine transgression over an area that had been subject to a very long period of arid to semi-arid conditions. In many areas the Kupferschiefer overlies red-bed sediments (Rotliegende), but in others it overlies Carboniferous sandstones and marls or the bleached and reworked equivalents of earlier rocks (Grauliegende and Weissliegende). Within the Kupferschiefer, lithologieal variations can be related to detailed paleogeography. Overall a euxinie, sapropelie facies predominates, but changes occur in the region of paleohighs where more carbonate and elastic-rich facies are developed. Strong evidence exists for the development of chemical stratification in the Zeehstein sea (from which the Kupfersehiefer was deposited) with oxidizing conditions in the upper part and reducing conditions in the lower part. Everywhere the Kupferschiefer grades upward into overlying dolomitie limestones. Although large areas of the Kupfersehiefer contain only average concentrations of base and precious metals compared to other shales and marls, in certain areas the concentrations reach ore grade. Historically, the Mansfeld district (SE Harz Mountains) was important for copper and silver mining, but at present-day mining is undertaken only in the Spremberg-Weisswasser area (East Germany) and in Lower Silesia (Poland). The ores in such regions contain sulfides of Cu, Pb, and Zn and may be enriched in a variety of other elements, notably V, Mo, U, Ag, As, Sb, Bi, and Se; Cd, T1, Au, Re, and the platinum-group metals are also reported; lateral and vertical zoning of Cu, Pb, and Zn may be observed; and in some areas, a reddening of the rocks adjacent to ores (Rote Fiiule facies) is a useful exploration guide. The Kupfersehiefer in Poland, in two contrasting regions in Germany (the Lower Rhine basin and the Hessian depression) and in England (where it is termed the Marl Slate) are compared and provide evidence for four types of mineralization. The first (and oldest) is a weakly mineralized type exemplified by the English Marl Slate. Average base metal content of this type is • 100 ppm. Detailed mineralogieal, geochemical, and isotopic studies indicate that the mineralization is synsedimentary; these studies have enabled a model to be developed in which precipitation of the various mineral phases can be related to stratification of the early Zeehstein sea and oscillations in water and oxie-anoxie boundary levels. The second is an average mineralization involving base metal content at the 2,000-ppm level. In th...

The river Rhine has lain under considerable anthropogenic stress of its water quality for 100 years. As early as 1905 the first results of studies of the plankton in the Rhine were published. Due to the long residence time of the water a real potamoplankton can develop and at the end of the Lower Rhine it reaches its highest density. The paper consists of two parts. At first an overview is given about the history of plankton studies in the Rhine. The second part is the presentation of results from a monitoring at the Lower Rhine from 1979 to 2004.First systematic studies started at the beginning of the 20th century at the beginning of pollution. Our studies started during a phase of recreation from extreme pollution and eutrophication. Samples were taken at four stations: Bad Honnef, km 640, entrance to North Rhine-Westphalia, Du¨sseldorf, km 732, Duisburg, km 792 downstream large industrial effluents and big cities, Kleve-Bimmen, km 865 at the border to the Netherlands.In the 1970s nutrients were high, especially phosphate 0.65 mg PO 4 -P L À1 in 1979. After 1980 phosphate dropped to 0.11 mg PO 4 -P L À1 in 2004 (mean values of the growing season). Ammonia was reduced from about 0.52 (1979) to 0.02 (2004) mg NH 4 -N L À1 . Nitrate remained between 3.72 (1989) and 2.26 (2004) mg NO 3 -N L À1 at a relatively high level. Oxygen concentrations were very low during the 1960s and 1970s, sometimes only 4 mg L À1 O 2 . During our studies the oxygen increased up to 9 mg L À1 O 2 with a tendency to 11 mg L À1 O 2 in the last years. Chlorophyll a was estimated to be between 59 (1979) and 31mg L À1 (1986) with short peaks up to 170 mg L À1 (1989). Since 1992 the mean values have varied between 30 (1993) and 21 mg L À1 (2004).The floristic phytoplankton composition is characterised by the dominance of the centric diatom Stephanodiscus hantzschii. Other diatoms like Skeletonema subsalsum, Skeletonema potamos and Asterionella formosa were regularly present in smaller quantities. The second dominant group was coccale green algae. During the 1980s they formed up to 35% of the biomass. Since the 1990s their contribution to the phytoplankton became much smaller. This change corresponds with the increase of wastewater treatment and the diminution of nutrients. All the other groups of algae were present in minor quantities. During the time of higher trophy in the 1970s and 1980s the phytoplankton formed two peaks, in recent years only one peak has developed, depending on different flow conditions during the growing season and lower trophic state in the upstream parts of the river.Excellent correspondence exists between cell number, biovolume and chlorophyll a content and the results of delayed fluorescence (DF) measurement. The trophic status in the Lower Rhine may be estimated as (moderate) ARTICLE IN PRESSwww.elsevier.de/limno 0075-9511/$ -see front matter . The ecological status of the phytoplankton is good based on the requirements of the European Water Framework Directive (WFD).The zooplankton consists mainly of rotatoria and l...

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Nach der Revision von 1990 war eine erneute Revision der DIN 38410 „Ermittlung des Saprobienindex”︁ erforderlich, um im Zuge der regelmäßigen Aktualisierung den Erfahrungen bei ihrer Anwendung und neuen Erkenntnissen Rechnung zu tragen. In dieser Arbeit werden die λnderungen der Norm begründet, soweit sie nicht darin erläutert werden konnten. Außerdem erfolgt eine kritische Auseinandersetzung mit vorgebrachten Anregungen und Kritikpunkten. Besonders hingewiesen wird auf die Notwendigkeit der Qualitätssicherung bei der Ermittlung des Saprobienindex. Ein wesentlicher Bestandteil der erneuten Revision ist die Aktualisierung der Liste der Saprobie‐Indikatoren. Außerdem wurden typspezifische saprobielle Referenzbereiche für die einzelnen Typen der Fließgewässer Deutschlands eingeführt. Somit kann das Saprobiensystem als ein Metrik für die biologische Bewertung anhand der benthischen Fauna im Rahmen des Vollzugs der EG‐Wasserrahmenrichtlinie herangezogen werden. Darüber hinaus wurden viele Details der Norm schärfer gefasst. Die Listen der Indikatoren (Mikro‐ und Makrosaprobien) wurden in der Neufassung der Norm erheblich erweitert. In dieser Arbeit wird ebenfalls dargestellt, wie künftig beabsichtigte Erweiterungen zu handhaben sind, insbesondere auch bezüglich der Einbeziehung von Neozoen als Indikatoren im Saprobiensystem. Zur Absicherung des Saprobienindex steht weiterhin die Abundanzsumme zur Verfügung. Entsprechend der wesentlich erweiterten Liste der Indikatoren wurde die erforderliche Abundanzsumme von 15 auf 20 angehoben. Bei weiterer Absicherung des Ergebnisses mit gängigen statistischen Verfahren sollte deren Aussagekraft für die Methodik der Bestimmung des Saprobienindex und der jeweiligen Probestelle sichergestellt werden. Insbesondere in naturnahen, habitatreichen Gewässern ist eine heterogene Besiedlung mit großer Standardabweichung bezüglich der Saprobie‐Indikation möglich.