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GermanAls Reaktion auf die Verknappung der fossilen Energieträger und den Einfluss ihrer Verbrennungsprodukte auf die Umwelt ist es notwendig, Alternativen zu entwickeln und zu nutzen. Eine mögliche Alternative ist die Nutzung der Tiefen Geothermie. Für eine erfolgreiche Geothermieanlage muss der vorgesehene Nutzungshorizont geeignete hydraulische Parameter besitzen. Die Gesteine des Valangin und der Bückeberg-Formation sind potenziell geeignete Aquifere in Nordwestdeutschland. In dieser Arbeit werden vorliegende Porositäts- und Permeabilitätswerte sowie zugehörige Transmissibilitätsdaten entsprechend bewertet. Verteilungskarten mit Temperaturen aus dem 3D-Temperaturmodell des Geothermischen Informationssystems helfen bei der Einschätzung des zu erwartenden Temperaturintervalls. Die Daten zeigen, dass die Mindestrandbedingungen für einen geeigneten Geothermie-Aquifer, 250 mD Permeabilität, 20 % Porosität, 5 Dm Transmissibilität und 20 m Mächtigkeit, in einigen Verbreitungsgebieten gegeben sind und auch die Tiefenlagen für die erforderlichen Temperaturen erreicht werden. Im Ausblick wird auf das geowissenschaftliche Potenzial der Daten verwiesen, welches durch eine detailliertere Korrelation mit weiteren geologischen Informationen erschlossen werden kann.EnglishWith respect to the shortage of fossil energy sources and the impact of their combustion residues on the environment, it is necessary to develop and to utilise appropriate alternatives. One of them is the use of deep geothermal energy. A successful geothermal power plant needs a productive geological horizon with suitable properties. With respect to this aspect, the paper presents the porosity, permeability and the transmissibility of the rocks of the Valanginian and German Wealden (Bückeberg-Formation), which are possible useable aquifers in Northwest Germany. Some of the areas are fulfilling at least the constraints of a suitable geothermal aquifer, which are a permeability of 250 mD, a porosity of 20 %, and a formation thicker than 20 m. Temperature distribution maps, created with help of the 3D temperature model of the Geothermal Information System for Germany, support the assessment of the reachable temperature ranges. The entire geoscientific potential of this data could be developed with a detailed correlation with additional geological information.

Extensive geophysical research has taken place in North Germany between the cities of Bremerhaven and Cuxhaven to study a Pleistocene buried valley: the Cuxhavener Rinne. The valley forms an aquifer due to its sandy valley fill. It is in hydraulic contact with Miocene fine-grained sands. Lauenburg Clay covers the valley in wide areas. Together with younger clay layers, it contributes to the protection of the aquifer against possible pollution. A thick clay layer underlies both Neogene sediments and the buried valley and forms the lower barrier of the aquifer.Geophysical research included high-resolution seismic reflection lines, which give insight into the general shape and structure of the valley. Helicopter-borne electromagnetic measurements in frequency- and time-domain characterise the sand-clay distribution within the buried valley. An areal gravity survey is the base for the 3D density model, which connects two of the seismic lines. The collected and interpreted data served as input for a geological/geophysical 3D model of the area.Great care was taken to model the base of the Quaternary, which defines the shape of the buried valley. The combination of all data revealed detailed information about its location and the short distance changes of its course. Seismic data show a stepwise descent of the flank to the bottom of the valley. The clay beside the valley is indicated by SkyTEM data. Together with the gravity data, SkyTEM is a strong tool to map the valley and to close the gap between the seismic profiles. The Lauenburg Clay appears as a good conductor in the electromagnetic data. Its distribution is supported by drilling and seismic information. The Lauenburg Clay is bound to the valley limits and covers most of the deeper infill.

Triassic rocks rise above sea level in one place only in the German North Sea, on the small island of Helgoland, where Bunter rocks (Bunter Sandstone Formation) crop out. Gamma ray measurements in the Helgoland section are correlated to the North Sea well J/18-1. By this method the Helgoland section is connected to the Middle Bunter lithostratigraphy of the Northwest German Basin. The boundaries between Volpriehausen- and Detfurth Member, between Detfurth- and Hardegsen Member and between Hardegsen- and Solling Member have been determinated. Photographs of the Helgoland section illustrate these lithostratigraphic boundaries and prominent gamma-markers in the outcrop. Some megacycles of the Bunter Sandstone Formation and even smaller lithological units, e.g. Detfurth Zwischenmittel beds, can be traced through the whole basin. The Helgoland section shows a great thickness comparable to that in the Weser- and Ems Trough. The island geographically is situated in the center of the Northwest German Basin. However, the lack of some log cycles of the Hardegsen Member, truncated beneath the Hardegsen-Unconformity, demonstrate that it is not situated in one of the basin's subsidence centers. These are proved by seismic evidence to be in the Horn Graben and Glückstadt Graben. The demonstrated method to establish artificial gamma ray logs by outcrop measuring is shown to be helpful for correlating between beds in outcrops and in wells. It might be effective also for other types of lithological and stratigraphic sections.

Die Struktur Helgoland ist, entgegen früheren Auffassungen, kein Salzstock, sondern ein NW-SE-gestrecktes Salzkissen mit einem asymmetrisch gelegenen Scheitelgraben. Neben den Rotliegendsalinaren sind vor allem die Zechsteinsalinare am Strukturaufbau beteiligt. Die strukturelle Entwicklung des Salzkissens wird anhand eines geologischen Schnittes und Subcrop-Karten für Basis Unterkreide und Basis Mittelmiozän erläutert. Dabei zeigt sich, daß die größten Aufstiegsgeschwindigkeiten des Strukturdaches ab Mittelmiozän erreicht wurden und auch der Einbruch des Scheitelgrabens ein sehr junges Phänomen darstellt. Die Anlage der Struktur fand jedoch bereits vor der Ablagerung der Unterkreide, nämlich in Keuper und Jura statt.

The research project "Strukturatlas südliche Ostsee" (SASO) carries out a revision of reflection seismic profiles of the former organization Petrobaltik. From the analysis of the paleotectonic and neotectonic structural evolution possible pathways for the input of natural substances from the subsurface should be determined. According to reprocessed seismic profiles, the crystalline Precambrian basement of the Baltic continental margin and the overlying Cambro-Ordovician black shales extend further to the south and southwest than previously expected. Intracrustal reflections occur at depths of 8-12 km below the top of the basement. These reflections presumably represent the remainders of a short term subduction zone of late Ordovician to Silurian age. The black shales are interpreted to represent the main detachment for the overlying and highly deformed accretionary wedge. Due to the present structure of the Baltic continental margin and due to the regional extend of the accretionary wedge, right-lateral wrench tectonics seem reasonable during the Paleozoic convergence between the Baltic and Avalonia plates. The Mesozoic development of the facies and thicknesses along the northern margin of the "German Basin" is presented on the basis of well-logs and stratigraphic correlations. The taphrogenetic development is characterized by several rifting episodes since the early Permian. During late Jurassic new extension started which led to the formation of the late Mesozoic basins and grabens. These "pull-apart'-basins were inverted in the late Cretaceous (Santonian?) by transpressional movements along inherited (transcurrent?) fault zones. The basin centres were stronger upliftet than the rims, which can be detected by analyzing thickness variations of the late Cretaceous between the inverted basins and their corresponding marginal troughs. Tertiary Sediments are more or less removed by erosion with exception of the Danian. At the eastern edge of the Arkona-Block and in the area of the Nordadler-Kamien-Fault Sediments of this age can be expected. The original distribution and thickness of the Paleogene is difficult to reconstruct, because of an increasing regional uplift and erosion during the late Tertiary. The reason for this uplift might be the rifting in the centre of the North Sea. This led to an uplift and erosion of about 1000 m of the Paleogene sediments and a partial removal of the Cretaceous cover in the area. At the sites of the inversion structures, i.e. the Grimmen anticline and the inverted Gryfice-, Kolberg- and Rønne-Grabens, even early Jurassic and late Triassic Sediments were truncated. The target of the seismic surveys of the former Company GO Petrobaltik were the deep lying Paleozoic Sediments. Hence the quality and content of the uppermost reflections were deliberately reduced during acquisition by cutting off the signal at 62.5 Hz as well as during processing. A thorough investigation of the seismic grid spaced 1 to 2 km reveals a complex pattern of seismic anomalies in the first 300 msec. These are due to the morphology of the sea bed and the different physical properties of the Sediments and their structure beneath the sea bed. The Adler-Kamien-Faultsystem to the east of Rügen is clearly expressed in the uppermost reflections. This faultzone might posssibly be a pathway for upwards migration for geogene particles, fluids and gases into the ecosystem of the Baltic Sea.