Search Results - (Author, Cooperation:ZECK)

2019-10-22

Der Beitrag führt in die Thematik des Sammelbandes ein und stellt Grundlagen, Abläufe und Einsatzbereiche von Raumordnungsverfahren vor. Der erste Abschnitt des Beitrags geht der Frage nach, warum es in einer dynamischen Volkswirtschaft wie Deutschland einer Steuerung von größeren Vorhaben durch Raumordnungsverfahren bedarf. In einem zweiten Abschnitt wird erläutert, welche Funktionen das Raumordnungsverfahren im Zusammenspiel mit anderen Planungsinstrumenten wahrnimmt. Den möglichen Einsatzbereichen des Raumordnungsverfahrens ist der dritte Abschnitt gewidmet; hier wird aufgezählt, für welche Typen von Vorhaben Raumordnungsverfahren eingesetzt werden. Der vierte Abschnitt dieses Beitrags erläutert die behördlichen Zuständigkeiten, der fünfte stellt den Ablauf eines klassischen Raumordnungsverfahrens vor. Im Anschluss wird erörtert, wie sich die Durchführung eines Raumordnungsverfahrens auf die weitere Planung eines Vorhabens auswirkt. Den Abschluss bildet eine Einschätzung dazu, wie das Instrument des Raumordnungsverfahrens in Deutschland genutzt und wahrgenommen wird und welche Entwicklungen für den künftigen Einsatz dieses Planungsinstruments zu erwarten sind.

This paper introduces the topic of the volume and presents the foundations, processes and fields of application of spatial planning procedures. The first section of the paper explores the question of why, in a dynamic economy like Germany, it is necessary to control and manage larger projects through spatial planning. The second section addresses which functions spatial planning procedures assume in interaction with other planning instruments. The possible fields of application of spatial planning procedures are discussed in the third section, which enumerates the types of projects for which spatial planning procedures are utilised. The fourth section of the paper explains the administrative competences, the fifth presents the order of events of a classical spatial planning procedure. This is followed by consideration of how performing a spatial planning procedure impacts on the further planning of a project. The paper concludes with an assessment of how the instrument of the spatial planning procedure is used and perceived in Germany and what developments can be expected in the future utilisation of this planning tool.

Landscaping and area planning ; Städtebau, Raumplanung, Landschaftsgestaltung ; Raumordnungsverfahren; Raumverträglichkeit; spatial planning procedure; spatial compatibility ; Area Development Planning, Regional Research ; Raumplanung und Regionalforschung ; Bundesrepublik Deutschland ; Raumordnung ; Planungsinstrument ; Raumplanung ; Federal Republic of Germany ; spatial planning ; planning instrument ; zoning

Sammelwerksbeitrag, collection article

2019-10-19

Das "Netzausbaubeschleunigungsgesetz Übertragungsnetz" (NABEG) sieht für die Raum- und Umweltverträglichkeitsprüfung Ländergrenzen überschreitender Maßnahmen des Übertragungsnetzes das Instrument der Bundesfachplanung anstelle des Raumordnungsverfahrens (ROV) vor. Die Bundesnetzagentur ist hierfür die verfahrensführende Behörde. Das Bundesfachplanungsverfahren unterscheidet sich vom ROV v.a. durch die Verbindlichkeit des Ergebnisses und die Durchführung einer Strategischen Umweltprüfung als eigenständigen Verfahrensteil. Die Bundesfachplanung ist eng mit der Planfeststellung verzahnt, im ROV ist dies nur über eine freiwillige engere Zusammenarbeit zwischen Übertragungsnetzbetreiber und Planungsbehörden möglich. Da noch keine abschließenden Erfahrungen mit der Bundesfachplanung vorliegen, kann kein sachgerechter ergebnisbezogener Vergleich der Stärken und Schwächen der beiden Verfahrenswege erfolgen. Rückschlüsse zum etwaigen Anpassungsbedarf für ROV wären somit verfrüht.

The "Grid Expansion Acceleration Act Transmission Network" intends that the spatial compatibility and environmental impact of developments for the transmission network that cross state borders should be assessed using federal sectoral planning instead of a spatial planning procedure. The Federal Network Agency is the authority that leads the procedure. The federal sectoral planning procedure differs from the spatial planning procedure primarily in terms of the binding nature of the findings and the fact that a strategic environmental assessment is carried out as an independent component of the procedure. Federal sectoral planning is closely interconnected with planning approval. In the spatial planning procedure this is only possible through voluntary close cooperation between the operator of the transmission network and the planning authorities. As experience with the federal sectoral planning procedure is to date incomplete, it is not possible to conduct an proper results-related comparison of the strengths and weaknesses of the two procedures. Drawing conclusions related to the need to adapt the spatial planning procedure would thus be premature.

Städtebau, Raumplanung, Landschaftsgestaltung ; Landscaping and area planning ; Bundesfachplanung; Stromübertragungsnetz; Raumverträglichkeit; Verfahrensbeschleunigung; Verbindlichkeit; Federal sectoral planning; electric power transmission network; spatial compatibility; environmental impact; accelerating procedures; binding effect ; Raumplanung und Regionalforschung ; Area Development Planning, Regional Research ; Raumplanung ; Umweltverträglichkeit ; Energieversorgung ; Raumordnung ; Bundesrepublik Deutschland ; spatial planning ; environmental compatibility ; energy supply ; zoning ; Federal Republic of Germany

Sammelwerksbeitrag, collection article

2019-08-28

Im Jahr 2007 wurde die 'Biosphäre Bliesgau' (Saarland) per Rechtsverordnung nach deutschem Recht eingerichtet und 2009 durch die UNESCO als Biosphärenreservat anerkannt, womit auf ein rund zehnjähriges Bestehen zurückgeblickt werden kann. Vor diesem Hintergrund befassen sich die Autoren mit der derzeitigen Einschätzung der Bevölkerung (Jahr 2016) zur Entwicklung des Biosphärenreservates als einer Modellregion für nachhaltige Entwicklung. Die hier präsentierten Ergebnisse einer quantitativen Onlinebefragung beleuchten unter anderem, was die Befragten am Bliesgau schätzen, was sie mit dem Biosphärenreservat verbinden und welche Angebote die Befragten nutzen, also wie die Menschen die regionale Entwicklung im Kontext der Biosphärenreservatausweisung einschätzen. Es zeigt sich, dass die Institution des Biosphärenreservates durch die Befragten insgesamt positiv bewertet wird. Diese Einschätzung bezieht sich (in noch stärkerem Maße) auf die Landschaft des Bliesgaus, die durch die Einrichtung des Biosphärenreservates geschützt und entwickelt werden soll. Knapp zusammengefasst bedeutet das Biosphärenreservat für die Befragten die gesteigerte Verfügbarkeit regionaler Produkte in Kombination mit Landschafts- und Naturschutz.

In 2007 the ‘Biosphere Bliesgau‘ (Saarland) was established through an enactment in accordance with German law, and in 2009 the area was given UNESCO biosphere reserve status. The reserve thus looks back on ten years of existence. This is the context in which the authors investigate current public perceptions (in 2016) of the development of the biosphere reserve as a model region for sustainable development. The findings presented here are drawn from an online questionnaire and shed light on what those surveyed value about Bliesgau, what they associate with the biosphere reserve, what offerings they use, and thus how people assess the development of Bliesgau in the context of its designation as a biosphere reserve. It can be seen that the institution of the biosphere reserve is viewed overall positively by those questioned. This assessment applies (even more strongly) to the Bliesgau landscape, which should be protected and developed by the establishment of the biosphere reserve. Briefly summarised, for those surveyed the biosphere reserve represents increased availability of regional products in combination with landscape and nature protection.

Landscaping and area planning ; Ecology ; Städtebau, Raumplanung, Landschaftsgestaltung ; Ökologie ; Area Development Planning, Regional Research ; Ecology, Environment ; Ökologie und Umwelt ; Raumplanung und Regionalforschung ; Bundesrepublik Deutschland ; Saarland ; nachhaltige Entwicklung ; Biosphärenreservat ; öffentliche Meinung ; Landschaftsschutz ; Regionalplanung ; Landschaftspflege ; Naturschutz ; regionale Entwicklung ; landscape protection ; conservation ; landscape management ; public opinion ; regional planning ; Federal Republic of Germany ; biosphere reserve ; regional development ; sustainable development

Sammelwerksbeitrag, collection article

2022-09-26

Mit der Energiewende wird Energieerzeugung auf Grundlage erneuerbarer Energien dezentral und flächenintensiv. Bei der Solarenergie sind vorrangig Innenbereichspotenziale zu erschließen. Gleichwohl drängen Freiflächen-Photovoltaikanlagen zur solartechnischen Stromerzeugung zunehmend als neue Nutzung in den Außenbereich. Aufgrund dort vielfach auftretender Flächennutzungskonkurrenzen und Konflikte bedarf es einer aktiven raumplanerischen Steuerung. Dafür ist die regionale Planungsebene mit ihrem querschnittsorientierten, überörtlichen Betrachtungsansatz bei noch hinreichend gebietsscharfer Maßstäblichkeit besonders gut geeignet. Ihre planerischen Werkzeuge können je nach Steuerungsintention und der jeweiligen regionsspezifischen Handlungserfordernisse gezielt eingesetzt werden, wenn auch die Rechtsgrundlagen in Teilen dafür noch geschärft werden müssen. Neben förmlich-verbindlichen Steuerungsansätzen können auch informelle Ansätze einen Beitrag zur geordneten Entwicklung von FPV liefern.

In the course of the energy transition, energy generation based on renewable energies is becoming decentralised and land-intensive. In the case of solar energy, the priority is to develop the potentials of settlements for this land use. At the same time, ground-mounted photovoltaic systems for solar electricity generation are increasingly penetrating into greenfield areas outside of settlements. Due to the frequent competition and conflicts between land uses that occur in such areas, active spatial planning is required. The regional planning level is particularly well-suited for this purpose thanks to its cross-sectional, supra-local approach at a spatial scale that is sufficiently precise. Its planning tools can be used in a targeted manner in line with the management intention and the regional requirements, even if some honing of the legal foundations remains necessary. In addition to formally binding planning, informal approaches can also contribute to the orderly development of ground-mounted photovoltaic systems.

Landscaping and area planning ; Städtebau, Raumplanung, Landschaftsgestaltung ; Außenbereich; Energiewende; Energy transition; Flächenvorsorge; Freiflächen-Photovoltaikanlagen; Innenbereich; Photovoltaik; Vorbehaltsgebiete; Vorranggebiete; exterior area; förmlich-verbindliche Steuerungsansätze; informal planning approach; informelle Steuerungsansätze; interior area; obligatory planning approach; open space; open space-photovoltaic power plants; photovoltaic; priority areas; provision of areas; reserve areas; urban land-use planning ; Area Development Planning, Regional Research ; Raumplanung und Regionalforschung ; Bundesrepublik Deutschland ; Raumplanung ; Bauleitplanung ; Flächennutzung ; Regionalplanung ; Energieerzeugung ; Freiraum ; erneuerbare Energie ; latitude ; regional planning ; Federal Republic of Germany ; area utilization ; spatial planning ; energy production ; renewable energy ; urban land use planning

comment, Stellungnahme

2021-04-09

Der Beitrag befasst sicht mit den begrifflichen Grundlagen und Kenngrößen des Einzelhandels sowie mit Entwicklungen, die anhand ausgewählter Betriebsformen des stationären Einzelhandels- und des Online-Handels beschrieben werden. Weiteren wird auf die räumlichen Auswirkungen des Einzelhandels und die raumordnerischen und städtebaulichen Planungs- und Gestaltungsmöglichkeiten eingegangen. Diesbezüglich werden die bedeutsamen politischen und rechtlichen Rahmenbedingungen auf europäischer, nationaler, föderaler und kommunaler Ebene dargestellt.

Städtebau, Raumplanung, Landschaftsgestaltung ; Wirtschaft ; Landscaping and area planning ; Economics ; Raumplanung und Regionalforschung ; Wirtschaftssektoren ; Area Development Planning, Regional Research ; Economic Sectors

Sammelwerksbeitrag, collection article

1460-9568

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

We compared image computation in the rabbit retina by two different cell types: the so-called ‘local edge detecting’ ganglion cells and the well-known brisk–sustained ganglion cells. From both anatomical and physiological evidence, these cells are present in nearly equal numbers and thus overlap to sample the same regions of visual space. We recorded simultaneously from overlapping cells on a dense microelectrode array. The results were analysed using an anatomically realistic simulation of the retina's processing levels. The ‘local edge detecting’ cell was found to be tuned to higher spatial frequencies and to have a narrower spatial frequency bandpass than the brisk–sustained cells. Simulation revealed that this is due primarily to the ‘zero-crossing’ detector implied by the definition of the local edge detector. The outputs of the simulations in response to complex images were analysed quantitatively. The results showed the population of local edge detectors to transmit a sparser code than the brisk–sustained cells.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background    Mast cell activation has been assumed to play a role in dermal neurogenic inflammation: C fibre-derived neuropeptides activating mast cells and releasing histamine, which in turn would activate C fibres. Objective    To test this hypothesis mast cell tryptase (MCT) was measured inside the axon reflex flare area. Axon reflexes were elicited by histamine or compound 48/80, a polyanionic mast cell-degranulating substance. The time course of plasma extravasation and release of histamine and MCT from dermal mast cells in neurogenic inflammation was measured in vivo by intradermal microdialysis in humans. Methods    Single hollow plasmapheresis fibres (pore cutoff size: 3000 kDa) were inserted intracutaneously at the volar forearm and perfused with Ringer’s solution (4 μL/min) with one microdialysis fibre located at the planned stimulation site and a second inside the axon reflex area. Neurogenic inflammation was induced by intraprobe delivery of either histamine or the mast cell-degranulating agent compound 48/80. Mediator release was measured at the stimulation sites and inside the arising axon reflex flare area. Results    Mast cell degranulation induced marked plasma protein extravasation (PPE 0.25 ± 0.04–1.31 ± 0.6 mg/mL; pre- and post-stimulation, mean ± sem, n = 7) and release of histamine (2.0 ± 0.9–38.7 ± 1.4 ng/mL) and MCT (9.84 ± 2.4–92.2 ± 21.6 ng/mL). Interestingly, in addition to increasing PPE (0.33 ± 0.11–1.85 ± 0.9 mg/mL), histamine also induced a slight but significant increase in MCT (11.3 ± 3.0–12.4 ± 2.3 ng/mL). No evidence for mast cell activation was observed inside the axon reflex areas, where PPE (0.34 ± 0.03–0.25 ± 0.02 mg/mL), histamine (1.64 ± 0.5–1.46 ± 0.4 ng/mL) and MCT concentration (11.6 ± 3.1–7.6 ± 1.7 ng/mL) gradually decreased. Conclusion    It is concluded that dermal neurogenic inflammation does not degranulate mast cells.

Electronic Resource

1600-0625

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract Human dermal mast cells are capable of releasing cytokines, particularly preformed TNFα, upon appropriate stimulation. Masl cell activation in vivo was shown to be associated with an influx and activation of inflammatory cells, initially PMN “polymorphonuclear neutrophilic granulocytes” then eosinophils. In order to learn more about the mechanisms by which TNFα is capable of activating eosinophils, in the present study the effect of TNFα on morphology and function of highly purified normal eosinophils “≥95%” was examined. As estimated by transmission and scanning electron microscopy, TNFα-stimulated eosinophils appeared to be strictly adherent and flattened exhibiting a characteristic “hemispheric” shape. TNFα induced a dose-dependent, long-lasting production of reactive oxygen species as measured by lucigenin-dependent chemiluminescence (CL). even at a concentration of 0.001 U/ml. The maximal response upon stimulation with TNFα, however, was significantly lower than optimal effects induced by IL-5. TNFα-induced responses were completely inhibited by cytochalasin B and staurosporin, and partially blocked by pertussis toxin. Separation of eosinophils by discontinuous density gradients revealed the existence of at least two hypodense eosinophil populations with a distinct susceptibility to stimulation with TNFα. Based on functional assay systems, in contrast to a significant extracellular, only a small intracellular H2O2: production was detected. Accordingly, H2O2 production, detected by an ultrastructural technique, was observed only on the outer surface of the plasma membrane in the contact zones in between adjacent cells. Extracellular as well as intracellular production of H2O2; was completely inhibited by cytochalasin B. TNFα-induced activation of eosinophils is most probably mediated by binding to the 55 kD and the 75 kD TNF-receptor since both receptor molecules could be detected by FACS analysis and immune electron microscopy using receptor-specific antibodies. However, in contrast to its effect on eosinophil oxidative response, TNFα did not induce the release of significant concentrations of eosinophil cationic protein or eosinophil peroxidase in supernatants of cytokine-stimulated eosinophils, as detected by functional as well as immunological assay systems. These results clearly indicate that TNFα represents a potent eosinophil-activating cytokine which may be of relevance in the allergic inflammatory response.

Electronic Resource

1398-9995

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The complement system is an important amplification system for the propagation of allergic as well as pseudoallergic inflammatory reactions. In the present study, the effect of the major anaphylatoxin C5a was compared with that of platelet-activating factor (PAF) on highly purified eosinophils (≥95%) by functional as well as morphologic criteria. Upon stimulation with C5a, eosinophils maintained their spheric structure, developing short, pseudopodia-like protrusions, whereas PAF induced the generation of a number of digitating protrusions. As shown by functional and ultrastructural assay systems, both stimuli provoked significant extracellular and intracellular H2O2 production in eosinophils, which was inhibited by cytochalasin B. With C5a, a pronounced H2O2 production was detected within the small cytoplasmic vesicles, whereas PAF-induced H2O2 production was observed on the outer surface of the plasma membrane in the contact zones between adjacent cells. Morphologic signs of degranulation induced by C5a and PAF were accompanied by the significantly increased release of eosinophil cationic protein and eosinophil peroxidase in the presence of cytochalasin B. Like PAF, C5a induced a significant production of reactive oxygen species in eosinophils. as measured by lucigenin-dependent chemiluminescence (CL) responses in eosinophils. Maximal responses, comparable with those of interleukin-5 (100 U/ml), were observed at concentrations of 105--10-6 and 10-7-10-8 M for PAF and C5a, respectively. Separation of eosinophils by discontinuous density gradients revealed the existence of two hypodense eosinophil populations, one of them showing significantly reduced CL responses upon stimulation with C5a and PAF. In addition, CL responses upon stimulation with C5a and PAF were abrogated by cytochalasin B, staurosporine, and wortmannin, and were almost completely blocked by pertussis toxin. In conclusion, these data indicate that C5a induces events in human eosinophils comparable to those induced by PAF in the assay systems tested. Thus, C5a, generated after activation of the complement system, may be of major importance for the eosinophil activation observed in eosinophil-related disease.

Electronic Resource

0097-9740

Sociology

BOOK REVIEWS

0097-9740

Sociology

BOOK REVIEWS

0065-860X

Medicine

Psychology

0097-9740

Sociology

BOOK REVIEWS

1540-5931

Blackwell Publishing Journal Backfiles 1879-2005

Ethnic Sciences

Electronic Resource

1365-2133

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Summary The effect of recombinant human and murine interleukin-5 (IL-5) on granulocytes was investigated in patients with atopic dermatitis (AD) and allergic rhinitis and compared with those from patients with plaque psoriasis and normal non-atopic controls. Granulocyte activation was measured as lucigenin-dependent chemiluminescence (CL) and release of eosinophil cationic protein (ECP) as well as by scanning- and transmission-electron microscopy (EM) and the ultrastructural detection of production of H2O2 A significant direct effect of both human and murine IL-5 on granulocyte oxidative metabolism could only be detected in those patients with AD and allergic rhinitis. Also, as compared to normal controls, significantly increased CL responses were observed in these patients with stimulation with other granulocyte-activating cytokines. particularly GM-CSF. In patients with psoriasis there was no significant increase in response to stimulation with TNFα. TNEβ or GM-CSF. but IL-5 induced slight but significant CL responses in the granulocytes. None of the cytokines tested significantly stimulated the release of ECP in any of the groups.Ultrastructural studies showed that stimulation with human as well as murine IL-5 produced significant morphological changes in both eosinophils and polymorphonuclear neutrophilic granulocytes from the patients with AD. Production of H2o2 was visualized at the luminal part of the intracytoplasmic vesicles of the granulocytes and at the points of contact between the cells. On morphometric analysis, almost all the polymorphonuclear neutrophils in the patients with AD appeared to be activated. whereas only some of these cells in the normal controls showed signs of activation.

Electronic Resource

0022-1902

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Energy, Environment Protection, Nuclear Power Engineering

Electronic Resource

1432-0967

Springer Online Journal Archives 1860-2000

Geosciences

Abstract In the eastern, external part of the Grenvillian Belt in SW Sweden, five formations of granitic rocks were found in the basement of the Dalslandian Supracrustal Group. The granitic rocks have been strongly recrystallized but have preserved most of their granitic texture in the process. Most magmatic crystals have been pseudomorphed by metamorphic minerals: quartz, albite, chlorite, biotite, white mica, epidote, titanite, hematite, pyrite and carbonate. Two of the formations have subsequently been affected by a cataclastic deformation and at present consist of mylogneisses. δ 18O whole-rock values for the granitic rocks vary from +3.0‰ to +11.1‰. Quartz-apatite, quartz-zircon and quartz-titanite pairs show 18O/16O fractionations corresponding to equilibrium temperatures of 550–700° C, which are believed to reflect in the main continued closed-system isotopic exchange at high temperatures following solidification. In contrast highly positive 18O/16O fractionations for quartz-K-feldspar, quartz-biotite, quartz-chlorite and quartz-sericite pairs in some granitic samples indicate that these rocks have exchanged oxygen with heated, meteoric, H2O dominated fluids. Other granitic samples, however, show virtually undisturbed magmatic 18O/16O fractionation values for the same mineral pairs, even though these rocks are equally altered. It is concluded that all granitic rock units recrystallized under greenschist facies conditions during the infiltration of fluids under the influence of hydrothermal convection systems set up by the intrusion of the granitic plutons. The fluids probably had a range of δ 18O values from ca. -14‰ to ca. +10‰, indicating the mixing of distinct fluid reservoirs, one of meteoric origin and the others of magmatic and/or metamorphic origin. The temperature of alteration is estimated at 450–500° C. Estimation of pre-alteration δ 18O whole rock values for the five granitic units suggests that three units should be assigned a dominantly S-type origin, where as the other two units may partly or wholly have an I-type origin.

Electronic Resource

1437-3262

Springer Online Journal Archives 1860-2000

Geosciences

Abstract Rb-Sr isotope systematics have been investigated of epidote, actinolite, albite and biotite concentrates from 4 spilite samples from the Precambrian basement directly W of lake Vänern in SW Sweden. The rocks belong to the Dalsland Supracrustal Group whose basal conglomerate was deposited on an erosion surface with a maximum age of c. 1,200 Ma. Epidote-WR and actinolite-WR tie lines in a Nicolaysen diagram give ages with an average of 990±10 (la) Ma, which is thought to represent the metamorphic culmination. Biotite-WR lines yield an average age of 900±15 (1σ) Ma, which indicates the time at which the rock complex cooled through the isotopic closure temperature of biotite, estimated at c. 250° C. The average cooling rate in this period was very low, 1–2° C/Ma. Initial Sr isotopic ratios of the 4 spilite samples vary from 0.7040 to 0.7080 and are thought to reflect interaction of mantle-derived basalts with seawater.

Resume Une investigation systématique des isotopes de Rb-Sr a été effectuée sur des concentrés d'épidote, d'actinote, d'albite et de biotite de 4 échantillons de spillites provenant du socle pré-cambrien, immédiatement à l'ouest du lac Vänern, en Suède sud-occidentale. Ces roches appartiennent au groupe supracrustal daslandien dont le conglomérat de base s'est déposé sur une surface d'érosion d'un âge maximal de 1.200 Ma. Dans un diagramme de Nicolaysen, les jonctions épidote-roche totale et actinote-roche totale donnent un âge moyen de 990±10 Ma (1σ), qui est considéré comme représentant la culmination du métamorphisme. Les jonctions biotite-roche totale donnent un âge moyen de 900±15 Ma (1σ), qui indique le moment où le complexe rocheux est passé sous la température de fermeture isotopique de la biotite, estimée à 250° C. Le taux de refroidissement moyen à cette période était très bas: 1 à 2° C par Ma. Les rapports isotopiques initiaux des 4 spillites varient de 0,7040 à 0,7080; ils reflètent probablement des échanges isotopiques entre le basalte mantellique et l'eau de mer.

Zusammenfassung Die Rb-Sr Systematik in Epidot-, Aktinolith-, Albit- und Biotit-Konzentraten aus vier Spilitproben des Präkambrischen Grundgebirges unmittelbar westlich des Vänern-Sees in Südwestschweden wurde untersucht. Die Gesteine gehören zum Dalsland-Deckgebirge, dessen Basalkonglomerate auf eine Erosionsoberfläche mit einem Maximalalter von etwa 1200 Ma abgelagert worden sind. Verbindungslinien zwischen den Isotopendaten von Epidot und Gesamtgestein sowie Aktinolith und Gesamtgestein der einzelnen Proben ergeben ein mittleres Alter von 990±10 Ma (1σ). Dieses Alter wird als Zeitpunkt der Kulmination der Metamorphose gedeutet. Die Biotit-Gesamtgesteins-Alter zeigen einen Mittelwert von 900±15 (1σ) Ma; dieses Alter spiegelt den Zeitpunkt der Abkühlung des Gesteins auf 250° C wider und somit die Schließung des Rb-Sr-Systems für die hier untersuchten Biotite. Die mittlere Abkühlungsrate während dieser Zeit war sehr gering, in der Größenordnung von 1–2° C pro Ma. Die Sr-Initialverhältnisse der 4 untersuchten Spilitproben variieren von 0,7040 bis 0,7080 und werden als ein Zeichen für isotopischen Austausch zwischen den Mantelbasalten und dem Meerwasser gedeutet.

Electronic Resource

0040-4691

Linguistics and Literary Studies

0022-3840

Ethnic Sciences