ALBERT

Description: This study is based on a collection of Cephalopoda, belonging to the Zoological Museum, University of Copenhagen (Denmark), which Dr. J . Knudsen kindly entrusted to me. Most of the specimens were collected on the West African coast by different expeditions: "Dr. Th. Mortensen's Java-South Africa Expedition 1929-1930", the "Atlantide Expedition 1945-1946", "Dr. G. Thorson's Expedition to the Canary Islands 1947", and the "Galathea Expedition 1950-1952". Some other specimens from the West African coast or from other localities were added.

Description: The following report is a synthesis of the main results of the OECD Cooperative Programme on Eutrophication. It is the outcome of several years' concerted effort by 18 Member countries. The objectives were to establish, through international cooperation, a basis for eutrophication control of inland waters (lakes and reservoirs in particular), and to develop better guidelines for fixing nutrient load criteria compatible with water use objectives. The present report is both complementary and supplementary to the four Regional Project Reports (2) already published. In parallel with the OECD study programme, progress has been made in other areas, particularly in dynamic modelling. The results of the OECD study and approach have already been successfully applied in several instances in North America, Europe and elsewhere. It can be anticipated that 0- while knowledge of eutrophication and its control methods are advancing -- the OECD results presented here will continue to provide a basic reference in eutrophication control studies.

Description: The reproductive ecology of three sympatric hermit crab species from the Bay of Panama is examined. All three species reveal patterns of size and reproduction mediated by their supply of shells. Shells are demonstrated to be in limited supply. Crabs with shells large enough to allow growth, put effort into growth at the expense of reducing reproductive expenditures, while crabs in shells too small to permit growth allocate more time and effort into immediate reproductive gains. This resource regulated trade-off between growth and reproduction gives these tropical crabs plasticity in important life-history traits. Crabs with a relatively poor supply of shells reproduce at smaller sizes, reproduce more frequently, have larger clutches, and are unable to reach the larger sizes of crabs with a less limiting supply of shells. This flexibility in life-history traits allows these crabs to tailor their reproductive schedules to resource supplies controlled by gastropod mortality, as well as the presence of competitors and predators.

Description: The interaction between thrust and strike slip fault systems is well detailed in Pakistan where the Chaman transform zone connects the Makran and Himalayan convergence zones and contains an internal convergence zone in the Zhob district. The transform zone contains numerous strike slip faults of which the Chaman fault proper is the westernmost. We can demonstrate at least 200 km of left lateral displacement along the Chaman fault alone. In the Zhob belt N-S shortening by folds and a major thrust fault amounts to several dozen kilometres. The 400 km wide Makran convergence zone is now being shortened by E-W oriented folds, thrust faults, and reverse faults. As these faults in the Makran zone approach the transform zone, their traces bend to the N and motion on each of them becomes oblique, combining reverse and left lateral slip. They merge continuously with the strike slip faults of the Chaman transform zone. The Makran thrust system and the Chaman transform zone first became active in the late Oligocene or early Miocene. Later (Pliocene?), a component of left lateral shear occurred across the entire Makran Zone in association with the opening of the newly identified Haman-i-Mashkel fault trough S of the Chagai Hills and W of the Ras Koh. The total displacement and displacement rate across the Chaman transform zone varies in response to the rates of convergence in the plates E and W of the zone.

Description: Les données géologiques et géophysiques recueillies dans le golfe de Gascogne depuis 12 ans ont été partiellement réinterprétées d'après les forages IPOD du leg 48, et une nouvelle carte structurale en couleurs a été établie〈1〉. Cette carte montre la profondeur et l'extension du socle océanique et de la croûte continentale, amincie par les phases de distension mésozoïques et/ou épaissie par les phases de compression cénozoïques. Les structures sont classées d'après leur âge et leur nature: failles normales et décrochantes, témoins du « rifting » des marges armoricaine et aquitaine du Néocomien à l'Aptien; failles transformantes de la plaine abyssale, contemporaine de l'ouverture océanique de golfe à l' Albien et au Crétacé supérieur jusqu'au Santonien ; chevauchements, failles inverses, prismes d'accrétion tectonique, décrochements,failles normales et horsts créés par la subduction de la plaque européenne sous l'Ibérie du Maestrichtien (?) à l'Éocène moyen; enfin, structures tardives dues au rejeu à l'Oligocène ou au Miocène des accidents tectoniques antérieurs. Ces données structurales sont compatibles avec un modèle cinématique selon lequel l'Ibérie a subi, par rapport à l'Europe stable, au moins trois rotations successives depuis le Jurassique: déplacement en direction du sud-ouest au Crétacé inférieur jusqu'à l' Aptien supérieur; divergence et mouvement vers le sud-est de l' Aptien terminal au Santonien ; enfin, convergence et mouvement en direction du nord-ouest au Paléocène et à l'Éocène inférieur. IPOD drillings on the armorican margin allow to review geological and geophysical data collected in the Bay of Biscay for the past twelve years. They also allow to draw up a new structural sketch. The sketch displays the depth and extension of oceanic and continental basement. Structures fall into four catégories: 1) Neocomian-Aptian normal and associated probable strike-slip faults, related to the rifting of the armorican margin; 2) Albian-Santonian transform faults within the oceanic basement, resulting from the iberian rotation and correlative opening of the Bay of Biscay; 3) Maestrichtian(?)-middle Eocene thrusting, reverse faults, strike-slip faults, accretionary tectonic prism and normal faults linked to the subduction of the european plate beneath the north-spanish margin emphasised by a fossil marginal trench and a bulging of the deeping plate; and 4) Oligocene-Miocene reverse, normal and strike-slip faults. The structural data agree with a three phases kinematic model: a) Néocomian-Aptian NE-SW motion of the iberian plate with respect to the stable Europe (rifting); b) AlbianSantonian NW-SE drifting of lberia (and related oceanic accretion within the Bay); c) Paleocene-lower Eocene SE-NW converjence resulting in subduction of the european plate beneath the Iberian plate and subsequent shortening and thickening of the north-spanish margin.

Description: Samples collected at hourly intervals on May 18–19, 1980, at three sites 200 km downwind from Mount St. Helens, have made possible a detailed reconstruction of the conditions that contribute to the compositional heterogeneity of mineral and glass components observed in distal tephra layers. The air fall tephra deposited at the sites during the first 7 hours of the May 18 eruption is mostly coarse grained, microlite-rich, nonjuvenile glass and feldspar. Grain-size maxima in this initial tephra can be related to the cataclysmic blast at 0832 and a subsequent pulse of the eruption at 1200. Juvenile, microlite-free glass increases in relative abundance at the sampling sites beginning at about 1900. Such a change between nonjuvenile and juvenile tephra can be related to a 5-km increase in column height associated with the last major pulse of the eruption which occurred at 1700 at the volcano. Electron microprobe study of both microlite-rich and microlite-free pumice in the time series samples reveals significant compositional differences. Interstitial glass in nonjuvenile pumice deposited during the first few hours at the sampling sites is enriched in SiO2 and K2O and depleted in TiO2, FeO*, and MgO relative to juvenile glass. By comparison, major element composition of the least evolved juvenile glass sampled during the last several hours of the eruption displays a slight trend toward less evolved composition. Least squares calculations suggest that the more evolved character of the nonjuvenile glass can be explained by greater fractional crystallization brought about by enhanced cooling in a cryptodome prior to eruption, whereas the temporal changes observed in juvenile glass composition during the last several hours of the eruption suggest the presence of a small, slightly zoned magma chamber at depth. Electron microprobe study of glass-coated ilmenites, magnetites, and plagioclases provides the following estimates of the physical conditions in this reservoir: 865°±50°C, PH2O = 2.2 kbar and -log ƒO2 = 11.7. Analyses of bulk pumice, glass and selected mineral phases from May 25, June 12, July 22, and October 16–18 pumices erupted from Mount St. Helens indicate that the bulk pumice (magma) compositions have become slightly more andesitic with time, while mineral and co-existing glass compositions have changed significantly in post-May 18 eruptions with both being more highly evolved than those associated with the May 18 eruption. An application of the magnetite-ilmenite geothermometer to June 12 and July 22 samples indicates temperatures of 919°±30°C and 930°±50°C, respectively. Least squares calculations suggest that such evolved post-May 18 glass and mineral phases can be derived by fractional crystallization of a magma composition like bulk May 18 pumice into approximately 50% crystals and 50% residual liquid. Such partitioning between crystals and residual liquid appears to have occurred on the scale of centimeters and is interpreted as a consequence of accelerated crystallization under reduced water pressure.

Description: Studies of sexual maturation have been made on a large sample of Eledone cirrhosa from the North Sea off Aberdeen, Scotland. In females the wet weights of the ovary and oviducal glands have been recorded for a wide range of body sizes and related to the total body weight. The length dlstribution of a sample of eggs from each ovary was also measured. Assessed either by ovary enlargement or the mean egg length, female E. cirrhosa become mature at a wide ränge of body size and so state of maturity is not predictable from size of the animal. In males the total weight of genital bag is, by contrast, clearly correlated with body weight although this is not true for testis alone, presumably because of transfer of sperm from testis to spermatophoric sac.

Description: The ‘magnetic quiet zone’ in the eastern Gulf of Aden is located between the oceanic crust of Sheba Ridge and the continental crust of Arabia and Somalia, and is separated from both by important structural boundaries. The seaward boundary is marked by the end of the seafloor spreading magnetic anomaly sequence and by a basement depth discontinuity. The landward boundary is marked by escarpments made up of a series of normal faults. These escarpments extend from 2–3 km below sea-level to 1500 m above sea-level and are equivalent of the ‘hinge zone’ found at mature continental margins. The magnetic field in the quiet zone is flat in some areas and in others is characterized by anomalies of up to several hundred gammas which are correlatable over distances of up to about 20 km and which appear related to basement topography. The basement lacks the topographic slope characteristic of mid-ocean ridge flanks and is characterized by moderately rough relief. The crustal structure appears quite heterogeneous and where the crustal thicknesses have been determined, they are slightly greater than those of oceanic crust. New heat flow measurements show high values (95.7–123.3 mW m−2) in the quiet zone with values decreasing from Sheba Ridge toward the coast. The unusual structure of the quiet zone and the observations that more opening appears to have occurred between Arabia and Somalia than can be accounted for by the oceanic crust of Sheba Ridge leads to the suggestion that the magnetic quiet zone was generated by diffuse extension of continental crust through a combination of rotational (listric) faulting and dyke injection. This possibility is investigated using both a ‘stretching’ or ‘lithospheric attenuation’ model and a model in which a portion of the extension occurs through dyke injection. It is found that these models can adequately match the observed heat flow and basement depths although very large amounts of extension (β=4–6) are required in the deep seaward portion of the quiet zone. This results in more extension than is compatible with the documented motion between Arabia and Africa. However, formation of the magnetic quiet zone occurred over a period of 10–15 Myr rather than instantaneously as assumed in the simple models. When the effects of a finite length rifting episode are considered, less extension is required and the observed geophysical data are consistent with a diffuse extension origin for the magnetic quiet zone.

Description: Gut content analyses have shown that the diet of the long-finned squid, Loligo pealei, differs between inshore spawning and nursery grounds and offshore winter grounds. In this study, squid were collected inshore from May through November in lower Narragansett Bay, Rhode Island and offshore during winter along the continental shelf between Cape Hatteras and Cap Cod. In both collections crustaceans were more frequently consumed than either fish or squid, but fish were eaten by a wider size range of squid and more frequently inshore. Prey-type selection based on size was common in both samples, but it is unlikely that the species composition is the same in both areas. These data suggest that L. pealei is a highly opportunistic predator, whose diet primarily reflects the local abundance of potential prey species. Such a flexible feeding strategy could account for the large spatial and temporal variations which have been reported in the diet of this squid from various offshore areas.

Description: The oldest igneous rocks on Maio are pillow lavas of Mid-Ocean Ridge pillow basalts character which have been tilted and uplifted about 4 km from the ocean floor to outcrop as a partial ring, dipping steeply away from a central plutonic complex made up of pyroxenites, essexites, syenites and carbonatites. The ocean floor volcanic rocks are overlain conformably by a stratigraphically continuous pelagic carbonate succession which demonstrates a shallowing depositional environment from the Upper Jurassic to Upper Cretaceous times, when tuffaceous beds indicate renewed volcanism. The tuffs are associated with rudites demonstrating the emergence of the island and amongst the clasts are plutonics indicating Upper Cretaceous magmatism and the unroofing of the volcano to a substantial depth. Deformation under compressive stress resulted in the folding and local repetition by thrusting of this sedimentary cover, which, together with the plutonic core, had been intensively injected by major sills. The Mesozoic succession has been planed off and overlain with marked unconformity by a largely Neogene sequence of volcanic and terrestrial sedimentary rocks. There is a hiatus throughout the Palaeogene, and constructional activity appears to recommence with ankaramitic hyaloclastite and lava deltas and subaerial ankaramitic flows. These are overlain by fluvial sediments and tuffs. Stratigraphically above these is an extensive plateau of silica-undersaturated lavas, olivine-melilitites and nephelinites, which rest on a planed and locally lateritized surface. At topographically higher levels in the eastern part of the island there are thick ankaramitic lavas and pyroclasts which evidently flowed eastward through valleys cut down into the Mesozoic strata, and appear to be of Pliocene age. The subsequent history of the island appears to be non-volcanic.

Description: The authors believe that Globorotalia mayeri Cushman and Ellisor and Globorotalia siakensis LeRoy cannot be maintained as separate taxa. This opinion comes after reexamination of the holotype of Globorotalia mayeri and of additional illustrations of the holotype of Globorotalia siakensis together with examination of large numbers of specimens of the plexus from Bodjonegoro-1 well in Java and from Trinidad in the Caribbean. Both taxa were described in 1939 but, due to the rules of priority, Globorotalia mayeri would now be the valid name. We consider that Globorotalia continuosa Blow is a four-chambered variant of Globorotalia mayeri that cannot usefully be separated from it.

Description: The major light and dark components of body displays are described and classified for the octopus Eledone cirrhosa (Lamarck) under aquarium conditions. Comparisons are made with Octopus vulgaris and Eledone moschata. Upon the basic similarity of white display components in the three species is superimposed a trend of modification. Dark components are less various in Eledone cirrhosa and although the chromatophores are organised with leucophores into chromatic units these are not clearly limited morphologically by “grooves”. The mottle patterns of Eledone seem to be arranged along the longitudinal and latitudinal (radial) axes of the animal, the grade of mottle does not respond to grade of background contrast.

Description: During a 10-year study more than 2,000 phytoplankton samples were collected from the entire coast of Peru and analyzed. In general, diatoms were the most abundant group of organisms in all seasons. Predominant species were Rhizosolenia delicatula, Skeletonema costatum Thalassiosira subtilis, Thalassionema nitzschioides and several species of the genus Chaetooeros. Dinoflagellates and flagellates were observed frequently during summer. The mean distribution of the phytoplankton concentration during the 10 years shows the existence of several centers with higher cell densities along the coast, coinciding with the areas of more intense and persistent upwelling. Four major centers have been identified: Pimentel (˜6°S), Chimbote (˜9°S), Callao (˜12°S), and Tambo de Mora-Pisco (˜15°S); and two minor centers, Talara (˜4°S) and Ilo (˜17°S). The relative importance of each center seems to change according to the season. The highest phytoplankton concentration tended to be in the northern part of the coast during fall and winter and in the south through spring and summer.

Description: Sponges are diploblastic acoelomate Metazoa. They are sedentary, filter-feeding animals which utilize a layer of flagellated cells to pump a unidirectional water current through themselves. They are found in freshwater, but more abundantly in marine habitats. Sponges have been persistent throughout geological time from the Precambrian to the Recent, with special success during the Paleozoic. They are apparently the most primitive multicellular animals on a phylogenetic scale ranked by morphological complexity, although the levels of physiological and biochemical complexity found in sponges easily measure up to the degree of sophistication found in so-called higher animals. The Porifera (sponges) and Coelenterata are related as two phyla representing distinct stocks, but stemming from a presumed common although presently unknown origin (Hyman, 1940).

Description: The type species of Dictyonema is D. retiforme Hall, 1851 from the Middle Silurian Rochester Shale of New York. Although incomplete, the type specimen probably belongs to the benthic group of dendroid graptolites which ranged from the Late Cambrian to early Late Carboniferous. It is proposed that the plank tie, near-cosmopolitan 'Dictyonema' flabelliforme is phylogenetically quite distinct and belongs to the unattached coni-siculate dendroid family Anisograptidae Bulman, with Radiograptus Bulman as probable ancestor. The Anisograptidae are not directly related to the benthic dendroid family Dendwgraptidae Roemer, of which Dictyonema is a member, although they may be indirectly descended from it. The planktic species 'Dictyonema' flabelliforme is revised and referred to the genus Rhabdinopora Eichwald, 1855. 'Dictyonema' norvegicum Kjerulf and 'D' graptolithinum Kjerulf are regarded as junior synonyms of Rhabdinopora flabelliformis (Eichwald). The coni-siculate planktic family Anisograptidae is reorganized into three subfamilies. The Anisograptinae n. subfam. includes essentially horizontal pauci- or non-dissepimentous genera (Radiograptus, Staurograptus, Anisograptus, Adelograptus, Aletograptus, Triograptus and Kiaerograptus); the Rhabdinoporinae n. subfam. includes pendent conical genera (Rhabdinopora, Bryograptus and doubtfully Sagenograptus); and the (possibly polyphyletic) Clonograptinae n. subfam. includes horizontal forms principally developing from a single dicalycal bud of th11 (Cionograptus, Temnograptus, ?Stellatograptus).

Description: Living specimens of Globigerinoides sacculifer (Brady) were subjected to varying degrees of damage in 2 series of experiments. In the first 3-group experiment, one, two or all chambers of the shells were crushed, whereas in the second 3-group experiment, successive chambers were amputated from the shells. The purpose of both sets of experiments was to determine the relative rate of recovery of and mode of shell regeneration by the injured organisms. The great majority in 5 of the 6 groups recovered and continued shell growth by regenerating spines, cementing broken parts, adding new chambers and undergoing gametogenesis. The shell shapes which resulted from the crushed specimens were generally bizarre, whereas the amputated specimens regrew chambers of normal shape. The nucleus in adult G. sacculifer shells appears to be located in the F-3 or earlier chamber. Our experiments indicate that in spite of severe injury to the shell, these tenacious marine protozoans can generally restore their biological functions of calcification, predation, symbiosis with algae, and gametogenesis. In nature, abnormal shells which show evidence of physical damage are most likely caused by predators; thus their frequency reflects a relative predation pressure on planktonic foraminifera.

Description: The growth of the octopus Eledone cirrhosa has been studied in a population from the North Sea off Aberdeen. Data are presented for the growth of individuals isolated in aquarium conditions; the growth of size classes in thefieldpopulation; and preliminary information on the growth relationships of gonad, somatic, cardiac and brain components of the body. At 15 °C Eledone cirrhosa is capable of growing from 10 to 1000 g in 270 days. From octopuses which feed readily in captivity, weight specific growth rates of up to about 3–5 % day-1 for animals of 100 g body weight are recorded, falling to a maximum of about 1–5 % day-1 at body sizes above 500 g. Females stop growing when sexually mature, but in the sample captured they were consistently larger than males, a feature which may account for the 7:1 bias towards the incidence of females. On a wet-weight basis, the mean food incorporation into growth is 37 % of the food ingested, which is 49% of the gross weight of crabs killed. Field data for 1978/79 suggest that animals recruited to the population at the beginning of the year grew steadily until December, overwintered without growing, then grew rapidly for several months in the subsequent year before disappearing from the samples. The estimated average age of those animals and by implication, the life span, is 20 months.

Description: Mesozoic deep water sedimentary rocks uplifted and exposed in basement complexes on the islands of Fuerteventura (Canary Islands) and Maio (Cape Verdes) help document the early Atlantic ocean and the volcanic history of these islands. On Fuerteventura ca. 1.5 km of terrigenous quartzose clastics, black shales, and subordinate redeposited limestones of early Cretaceous age are overlain first by Albian-Cenomanian marls and clastics, showing extensive soft sediment slumping, then after a hiatus by Senonian nannofossil chalks with chert nodules. After a further break alkalic submarine volcanic rocks, largely hyaloclastics, were erupted, then overlain by redeposited bioclastic limestones and volcaniclastics of Oligocene age. A dyke complex was intruded, then the basement complex was uplifted, peneplaned, and overlain by Neogene plateau lavas. On Maio the basement complex comprises mafic pillow lavas of midocean ridge character overlain by up to 4 00 m of deep water sedimentary rocks. Upper Jurassic to lower Cretaceous radiolarianrich pelagic limestones are succeeded by middle and upper Cretaceous sequences of mudstones, redeposited limestones, chalks, tuffs, and volcaniclastics which document the onset of volcanism. During a sedimentary hiatus plutonic rocks were intruded, uplifted, then eroded to produce conglomerates of late Miocene age. These are overlain by several series of gently dipping subaerial alkaline basalt flows. Comparisons with D.S.D.P. sites, oil wells and on land geology confirm that the lower Cretaceous Fuerteventura quartzose clastics formed part of a deep water fan complex located close to the Atlantic continent-ocean boundary. Comparable flysch is known in the Moroccan basin, in the Betic-Maghrebide system and the feeding Tan-Tan-Cape Bojador delta system. The inferred disconformity between Cenomanian and Senonian is part of a widespread depositional hiatus associated with slumping on the adjacent west African continental margin. On Maio pelagic limestones comparable with the Tethyan Maiolica facies were deposited on a subsiding? middle/late Jurassic ocean ridge before uplift related to onset of volcanism probably in the late Cretaceous.

Description: Sedimentation rates (corrected for compaction) from along the passive continental margin of Africa between the Equatorial Fracture Zone and Somalia are used to compare the rates of subsidence of the continental crust since early Mesozoic time. Three distinctive subsidence histories can be identified which correspond with basinal areas that have different structural styles: rifted (west coast), sheared (Equatorial and Agulhas fracture zones) and sunk (zones of vertical tectonics in eastern Africa). A comparison of subsidence rates with other tensional margins (NE USA and the North Sea) and a consideration of the plate tectonic history of the African margins leads to the proposal of a geo and thermodynamic model that takes cognizance of the worldwide mid-Cretaceous rheological discontinuity between taphrogenic and epeirogenic basin formation recognized by Kent, and the more generally accepted, purely plate tectonic driven model of margin subsidence. The new suggestion involves a lower Mesozoic worldwide rise in the geothermal gradient in the lithosphere which produces metamorphism of the base of the continental crust and initiates taphrogenesis along lineaments throughout Gondwanaland. A lowering of the geothermal gradient in the lower Cretaceous produces a switch to epeirogenic subsidence, driven solely by sediment loading and thermal contraction, by Aptian/Albian times. The thermal event facilitated continental separation, and sea floor spreading commenced locally at various times along the active taphrogenic belts. Local thermal and tectonic aberrations associated with this phenomenon over print onto the worldwide pattern of marginal basin subsidence. A further rise in the geothermal gradient may have been responsible for renewed taphrogenesis in eastern Africa in Tertiary times.

Description: There has been concern about recent temperature trends and the future effects of CO2 concentrations in the atmosphere1,2; but instrumental records only cover a few decades to a few centuries and it is essential that proxy data sources, such as pollen spectra from peats and lake sediments, be carefully interpreted as climate records. Several workers have shown statistically significant associations between the modern pollen rain and climatic parameters, an approach that by-passes the recognition of pollen/vegetation units. Statistically defined equations that associate abiotic and biotic elements are called transfer functions. We report here on the application of transfer function equations to nine middle and late Holocene peat and lake sediment sequences from northern Canada (Fig. 1).

Description: Before making a critical evaluation of the crude oil and natural gas prospects for the years to the end of the century, it is necessary to review the geology and structure of the three German hydrocarbon-producing provinces. Furthermore, past exploration, production and reserves should be discussed. The three hydrocarbon-producing provinces are: the NW German Basin, the Upper Rhine Graben and the Molasse Basin, which together make up about 41% of West German territory (Fig. 1). The NW German Basin contains a sedimentary sequence over 8,000 m thick ranging in age from Permian to Quaternary. Gas and oil, the two natural hydrocarbons, are generally confined to separate lower and higher stratigraphic levels respectively (Fig. 2). The NW German Basin is the most important prospective area in West Germany. It extends into the North Sea. The tectonic rift feature of the Upper Rhine Graben originated in the Eocene. The Tertiary fill is over 4,000 m thick. Oil is found mainly in Mesozoic, Eocene and Oligocene rocks; the Miocene and Pliocene reservoir rocks contain natural gas almost exclusively (Fig. 3). The Molasse Basin is part of the foredeep north of the Alpine and Carpathian mountain ranges. The basin is filled with Upper Eocene to Pliocene and Quaternary sediments which, near the Alpine nappes, reach a thickness of over 5,000m (Fig. 4). During this century there were peaks in annual oil-production in 1910, 1940 and 1968 (see Fig. 5). The 1910 peak was the result of drilling activity in the Wietze oilfield. During the period 1934–1945, government financial aid was made available for drilling exploration wells. The success of this collaboration is demonstrated by the oil output in 1940 of 1 × 106 t. After World War II, many different types of oil-bearing structure were found, particularly by reflection seismic techniques in conjunction with detailed stratigraphical and palaeogeographical investigations. The success achieved can be seen by the peak of 8 × 106 t oil production for 1968 (Fig. 5) and in the growth of oil reserves (Fig. 7). Intensive exploration also enabled many new gasfields to be developed, especially in the deeper horizons of the NW German Basin. In 1971, estimated gas reserves reached 360 × 109 m3 (Fig. 11), and annual gas production in 1979 was 20.7 × 109 m3 (731 Bcf) (Fig. 9). There is, no doubt, still scope for the discovery and exploitation of oil and gas in Germany, especially in the NW German Basin where the best prospects for the future lie. This is borne out by two recent offshore oil discoveries and also by the successful application of enhanced recovery methods in the oilfields. The chances of finding more gas at the lower stratigraphic levels are promising now that gas has been discovered in the deeper parts of the Permian basin. The results of massive-hydraulic-fracturing tests in low-permeability pay-horizons are also encouraging. The deeper parts of oil- and gas-producing basins contain interesting prospects and have yet to be tested by ultra-deep wells. Provided that the economic climate remains favourable, there should be no difficulty in finding and supplying German oil and gas in the future. Geologically and technically possible reserves should be converted into proven and/or probable reserves. German crude oil will be available for several years beyond the year 2000, and German natural gas for a far longer time. A production rate of 19 to 20 × 109 m3 of gas per annum is feasible over the next twenty years, and oil production will probably not sink below 3 × 106 t/a in this period.

Description: Large euhedral crystals of calcium carbonate hexahydrate were recovered from a shelf basin of the Bransfield Strait, Antarctic Peninsula, at a water depth of 1950 meters and sub-zero bottom water temperatures. The chemistry, mineralogy, and stable isotope composition of this hydrated calcium carbonate phase, its environment of formation, and its mode of precipitation confirm the properties variously attributed to hypothetical precursors of the glendonites and thereby greatly expand their use in paleoceanographic interpretation.

Description: The morphological peculiarities of the Mazocraeidae, in particular the clamp structures, are discussed and a Latin nomenclature for the elements of the clamp skeleton is suggested. 3 new genera and 6 new species are then described

Description: Acoustic basement lies at an average of between 6.0 and 6.5 sec two-way time below sea level in the southern Rockall Trough and northern Porcupine Abyssal Plain. The overlying sedimentary succession reaches maximum thicknesses of at least 4.0 sec, and can be divided by 3 regionally-developed seismic reflecting horizons, which are used as a framework to establish an acoustic stratigraphy for the area by selecting three “type” seismic sections. These reflectors are named, in ascending order, Shackleton, Charcot and Challenger. The area is crossed by E—W basement high structures, the Clare Lineament (which may be an easterly extension of the Charlie Gibbs Fracture Zone), that separates the Porcupine Abyssal Plain from the eastern part of southern Rockall Trough. Under the latter, the post-Shackleton acoustic sequence is thickened, as if dammed to the north of the Clare Lineament, whilst a further thickening, above reflector Charcot, occurs along a NE—SW line somewhat farther north into the southern Rockall Trough. This can also be related to shallow-lying acoustic basement features. Pre-Shackleton sediments overlie a very irregular basement topography. The acoustic characters of the various sediment packages are described and it is speculated that major changes in the sedimentary environments took place across reflectors Shackleton and Challenger, the latter probably establishing the modern bottom current circulation patterns. No ages can be unequivocally assigned to the main reflectors, but previously published data suggest a late Eocene—Oligocene age for Challenger. Possible lavas or sills are identified in the succession between reflectors Shackleton and Charcot.

Description: The planktonic foraminifer Globigerinoides sacculifer (Brady) was cultured under two different light intensities and in continuous darkness. High light intensity (HLI = 4oo-soo einsteins/m2/s) resulted in a longer lifespan, a greater number of chambers formed, and a larger final shell size compared with individuals cultured under low light intensity (LLI = 20-50 einsteins/m2/s) or in continuous darkness. Shell growth rates were unaffected by increasing light intensity, but gametogenesis was delayed. Continuous darkness induced a rapid onset of gametogenesis in organisms with shell lengths larger than 250 m. Feeding frequency had a greater effect on growth and reproduction than light intensity under conditions of LLI and HLI, but continuous darkness had an overriding effect on growth and reproduction owing to the rapid onset of gametogenesis which terminated the life of the mother cell. Our previous data indicated that the longevity of G. sacculifer was dependent on feeding frequency, and that G. sacculifer cultured under LLI had a lifespan of approximately 2-4 weeks. Present results suggest that the lifespan can vary from a minimum of 8 days for organisms fed daily in continuous darkness to a maximum of 54 days for organisms fed once every 7 days and maintained in HLI. It is concluded that individual G. sacculifer attain a shell size greater than 6oo ,urn only if they maintain their position in the euphotic zone. Prolonged existence below the euphotic zone would result in premature death or gametogenesis following stunted shell growth.

Description: In der Zeit vom 7.10. bis 20.10. nahm F.S. "Poseidon" an dem Feldexperiment KonTur teil. Neben "Poseidon" waren an diesem Feldexperiment beteiligt: F.S. "Meteor", F.S. "Gauß", Feuerschiff "Borkumriff", Feuerschiff "Elbe 111, F.K. "Regulus", die Forschungsplattform "Nordsee", sowie die Flugzeuge C 130 Herkules der M.R.F. - Farnborough, und die Falcon 20 der DFVLR - Oberpfaffenhofen. Das Experiment diente zur Untersuchung von Konvektion und Turbulenz und wurde von der auf dem Flughafen Nordholz eingerichteten KonTur-Leitstelle koordiniert.(Eine ausführliche Darstellung der wissenschaftlichen Zielsetzung findet sich im Expeditionsheft.)

Description: Die Forschungsfahrt diente der Durchführung des Forschungsvertrages "Ein integriertes akustisches Fernmeßsystem (IAFM) zur Typisierung von Schichtfolgen im Meeresboden und ihrer Raumlage". Dazu sollten den bis jetzt verfügbaren Komponenten des IAFM Systems. zusammen mit dem -nach Prototyp- gebauten Echostärkenmeßgerät-2 in einigen durch frühere Fahrten gut bekannten Gebieten erprobt werden. Gezielt entnommene Kerne sollten die Interpretation der Sedimentschiebtfolge ergänzen. Da das Gerät Einzelheiten über die Reflexionseigenschaften der oberen Sedimentschichten von 50 cm (5 Abschnitte je 10 cm Mächtigkeit), 1 m, 2 m und 4 m und die unteren Schichten von 50 cm bis 1 m, 1 m bis 2 m, 2 m bis 4 m und 4 m bis 8 m erfassen kann, sollten Profilabschnitte für nachträgliche Signalverarbeitung im Labor auf Analogband eingespeichert werden. Außerdem sollte der Einfluß der Schiffsgeschwindigkeit auf die einzelnen Echostärken untersucht werden. Da die Fahrt durch Motorenschaden am Schiff gekürzt werden mußte, wurden die Unter-suchungen auf folgende Gebiete eingeschränkt: a) Vejsnäs Flach und Rinne - Fehmarn Belt b) Mecklenburger und Neustädter /Lübecker Bucht c) Kriegers Flach

Description: Im Rahmen der Forschungsfahrt wurden wissenschaftliche Fragestellungen der Nährstoffchemie, der organischen Chemie, der Planktologie und der Mikrobiologie interdisziplinär und zum Teil in internationaler Zusammenarbeit mit schwedischen ("ARGOS", Planktol./Chem.) und estnischen ("AYU DAG", Phys.) Arbeitsgruppen bearbeitet. Die internationale Zusammenarbeit betraf vor allem die synoptische Untersuchung kleinräumiger Veränderlichkeiten chemischer, physikalischer und planktologischer Parameter im Rahmen eines vom BMFT und der DFG geförderten Projektes. Die Pronennahme für die planktologischen, mirkobiologischen und z.T. auch für die org. chemischen Untersuchungen orientierten sich an den Probennahmen dieses Programms, um zeitlich und räumlich interdisziplinär vergleichbare Daten zu erhalten.

Description: Die 75. "Poseidon"-Fahrt in die Ostsee wurde als kombiniertes chemisch-physikalisches -Experiment durchgeführt. Teilnehmende Schiffe waren außer F.S. "Poseidon" F.S."Alkor" und R.V. "Ayu Dag" der Estnischen Akademie der Wissenschaften. Es wurden Untersuchungen auf den Gebieten 1) Organische Substanzen im Meerwasser und in der Atmosphäre 2) Spurenmetalle im Meerwasser 3) Kleinräunige Variationen chemischer und physikalischer Parameter (koordinierte Messungen "Ayu Dag" und "Poseidon") durchgeführt.

Description: Zwischen dem 6.5.1982 und dem 25.5.1982 wurden zwischen Bornholm und Gotland auf 56 Stationen Proben zur biologischen Struktur des Pelagials und des Benthals genommen. Ausgehend von der ersten Station bei Bornholm am 7.5.1982 wurde eine Meßserie bis zur Nordspitze Gotlands durchgeführt. Auf diesem Schnitt wurden alle 2o sm Sondenprofile und alle 6o sm diskrete Wasserproben genommen. Vor Gotland wurde ein Tagesgang aufgenommen und Sinkstoffallen ausgesetzt. Danach wurde ein Schnitt mit denselben Stationen zurück zur BOSEX- Station gefahren, wo eine einwöchige Dauerstation durchgeführt wurde. Hier wurden sowohl eine einwöchige Sinkstoffallenverankerung ausgelegt, als auch Tagesverankerungen und treibende Fallen eingesetzt. Auf dem Weg nach Slite (Gotland) zum wassernehmen wurden auf 5 Stationen vom Tiefen ins Flache Backengreiferproben genommen. Nach dem Hafentag erfolgte eine dreitägige Dauerstation mit Sinkstoffalleneinsatz an der Nordspitze Gotlands. Auf der Rückfahrt wurden dieselben Stationen wie auf der Hinfahrt nochmals angelaufen und in der gleichen Weise beprobt. Auf der BOSEX-Station wurde noch ein Tagesgang gemessen und Sinkstoffallen eingesetzt.

Description: Rhodopseudomonas globiformis is able to grow on sulfate as sole source of sulfur, but only at concentrations below 1 mM. Good growth was observed with thiosulfate, cysteine or methionine as sulfur sources. Tetrathionate supported slow growth. Sulfide and sulfite were growth inhibitory. Growth inhibition by higher sulfate concentrations was overcome by the addition of O-acetylserine, which is known as derepressor of sulfate-assimilating enzymes, and by reduced glutathione. All enzymes of the sulfate assimilation pathway. ATP-sulfurylase, adenylylphosphate-sulfotransferase, thiosulfonate reductase and O-acetylserine sulfhydrylase are present in R. globiformis. Sulfate was taken up by the cells and the sulfur incorporated into the amino acids cysteine, methionine and homocysteine. It is concluded, that the failure of R. globiformis to grow on higher concentrations of sulfate is caused by disregulation of the sulfate assimilation pathway. Some preliminary evidence for this view is given in comparing the activities of some of the involved enzymes after growth on different sulfur sources and by examining the effect of O-acetylserine on these activities.

Description: The ability to use adenosine 5′-phosphosulfate (APS) or 3′-phosphoadenosine 5′-phosphosulfate (PAPS) as the substrate for the initial reductive step in sulfate assimilation has been tested in most of the known Rhodospirillaceae species and in some chemotrophic bacteria. Improved and optimized methods for the synthesis and purification of the sulfonucleotides APS and PAPS are described. The production of acid volatile radioactivity from 35S-APS and 35S-PAPS was measured under various conditions in the presence and absence of non-labeled sulfate. Specific differences in the ability to reduce APS or PAPS were observed among the Rhodospirillaceae species and also the chemotrophic bacteria. APS was found to be the substrate of the thiolsulfotransferase in Rps. acidophila, Rps. globiformis, Rm. vannielii, Rc. purpureus, R. tenue, Rps. gelatinosa, in Alcaligenes eutrophus and Pseudomonas aeruginosa. PAPS was the substrate in Rps. capsulata, Rps. sphaeroides, Rps. sulfidophila, Rps. palustris, Rps. viridis, R. rubrum, R. fulvum, in Paracoccus denitrificans and in several Enterobacteriaceae. The presence of different enzymatic systems for sulfate reduction in the Rhodospirillaceae family is compared with their taxonomical grouping and their possible phylogenetic relatedness.

Description: Seegebiet: Nordöstlicher Nordatlantik

Description: Das Teilprojekt C2 des SFB 133 "Warmwassersphäre des Atlantiks" untersucht die mesoskalige Variabilität des Dichte- und Strömungsfeldes im Kanarenbecken. Im Vordergrund der diesjährigen Untersuchungen steht die Frage, in welchem Masse die Zirkulation im Tiefenbereich bis etwa 1500 m durch hydrographische Messungen erfasst werden kann und mit direkten Strömungsmessungen aus verankerten Meßsystemen bzw. aus satelliten-georteten Driftbojen in Einklang zu bringen ist. Da eine quasi-synoptische Aufnahme eines grösseren Areals bisher noch nicht zur Verfügung steht, sollte FS "Poseidon" während der Expedition "KANARENBECKEN 1982" die hydrographische Vermessung eines etwa 200 x 200 sm grossen Gebietes vornehmen, in dem die mesoskalige Aktivität besonders gross war. Meridionale Schnitte während der "METEOR"-Reise 56 (Abschnitt 5, Rückreise Antarktis) hatten gezeigt, daß im Bereich um 33°N, 22°W, im Frühjahr ein System von Temperatur-Salzgehaltsfronten vorhanden ist. Es lag nahe, daß diese Fronten mit starken Oberflächenströmungen verbunden waren. Daher wurde der Einsatz von 4 satellitengeorteten Driftbojen mit Segel in 100 m Tiefe vorgesehen, die bereits 14 Tage vor dem Beginn des Experiments durch FS "METEOR" ausgelegt werden sollten.

Description: Die Ausfahrt auf FS "Poseidon" diente der Erprobung verschiedener seismischer Geräte und Meßverfahren...

Description: The objective of this paper is to provide a general view on methods of wave field extrapolation as used in seismic modeling and seismic migration, i.e., the Kirchhoff-summation approach, the plane-wave method (k-f method), and the finite-difference technique.Particular emphasis is given to the relationship between the different methods. By formulating the problem in the space-frequency domain (x, y, omega -domain), a systems approach can be adopted which results in simple and concise expressions. These expressions clearly show that forward extrapolation is described by a spatial convolution procedure and inverse extrapolation is described by a spatial deconvolution procedure. In the situation of lateral velocity variations, the (de)convolution procedure becomes space-variant. The space-frequency domain is most suitable for recursive depth migration. In addition, frequency dependent properties such as absorption, dispersion, and spatial bandwidth can be handled easily.It is shown that all extrapolation methods are based on two equations: Taylor series and wave equation. In the Kirchhoff-summation approach all terms of the Taylor series are summed to an exact analytical expression--the Kirchhoff-integral for plane surfaces. It formulates the extrapolation procedure in terms of a spatial convolution integral which must be discretized in practical applications. The Fourier-transformed version of the Kirchhoff-integral is used in the plane wave method (k-f method). This actually means that spatial (de)convolution in the x, y, omega -domain is translated into multiplication in the k x , k y , omega -domain. Of course, this is not allowed if the extrapolation operators are space-variant.In explicit finite-difference techniques a truncated version of the Taylor series is used with some optimum adjustments of the coefficients. For only one or two terms in the Taylor series, a spatial low-pass filter must be applied to compensate for the amplitude errors at high tilt angles. Explicit methods are simple and most suitable for three-dimensional (3-D) applications.In implicit finite-difference schemes the wave field extrapolator is written in terms of an explicit forward extrapolator and an explicit inverse extrapolator. Properly designed implicit schemes do not show amplitude errors and, therefore, amplitude correction filters need not be applied. In comparison with explicit schemes, implicit schemes are more sensitive to improper boundary conditions at both ends of the data file.It is shown that the forward seismic model can be elegantly described by a matrix equation, using separate operators for downward and upward traveling waves. Using this model, inverse extrapolation involves one matrix inversion procedure to compensate for the downward propagation effects and one matrix inversion procedure to compensate for the upward propagation effects.

Description: Der Zückerrubenanbau hat sich in der Türkei seit seiner Einführung um die ersten Zuckerfabriken Alpullu und Usak besonders in den 50er Jahren entlang der Hauptverkehrswege über weite Landesteile ausbreiten können. Die sich heute auf 19 Fabrikbereiche und über 200 Anbaubezirke erstreckende Anbaufläche von 270.000 ha macht zwar nur knapp 2 Prozent der Ackerfläche aus, um so größer muß die von dieser überwiegend bewässerten Industriepflanze ausgehende Bedeutung des Zuckersektors für die Volkswirtschaft, den Industrialisierungsprozeß und die Modernisierung der Landwirtschaft bewertet werden. Die Anbauverträge erfordern eine gründliche Bodenverarbeitung, geregelte Fruchtfolge sowie sorgfältige Bewässerung und Bestandspflege. Zudem werden den überwiegend kleinbäuerlichen Produzenten Vorschüsse in barem Geld und Investitionskredite gewährt. Die Kampagne erfolgt über ein landesweites Netz von Wiegestationen in den Anbaudistrikten der Fabrikbereiche. Diese Rohstoffliefergebiete weisen als sektorale Funktionalregionen eine raumhierarchische Organisationsstruktur auf. Modernisierungseffekte werden dabei über die Fabriken, Bezirke und Dörfer bis in die landwirtschaftlichen Betriebe kanalisiert. Mit diesem Ansatz können Elemente der agrar- und industriegeographischen Standorttheorie mit zentralörtlichen und polarisationstheoretischen Konzepten verknüpft werden. Die in Hinterländern aufgebauten Disparitäten verändern sich ständig durch Verschiebungen im Standortgewicht des Anbaus. Am Beispiel des Anbaubezirks Beypazari bei Ankara wird deutlich, daß über die Zuckerrübe als 'culture motrice' eine schnelle weitere Intensivierung und Differenzierung in der Landwirtschaft ausgelöst wurde, die den Anbau dieser Entwicklungskultur schließlich wieder in Frage stellt. Im staatlich monopolisierten und gelenkten Zuckersektor kommt es sowohl beim Anbau als auch bei der Verarbeitung zu zahlreichen Kopplungseffekten. Diese könnten bei der zur Deckung des Eigenbedarfs notwendigen weiteren Expansion als Instrumente einer regionalen Agrarentwicklung und Strukturpolitik eingesetzt werden." (Autorenreferat)

Description: Im Rahmen dieses den Stand und die Aufgaben der Auswanderungsforschung in Deutschland und Skandinavien dokumentierenden Sammelbandes wurde versucht, den auf den Nordfriesischen Inseln noch heute ablaufenden Rückwanderungsprozeß aus Amerika in seinen Ursachen, Verläufen und besonders auch Auswirkungen auf das Heimatgebiet vor dem Hintergrund der besonderen regionalen und soziokulturellen Verhältnisse dieser alten und relativ gut erforschten deuschen Auswanderungslandschaft zu erfassen und zu erklären. Dazu war eine grundsätzliche, allgemein-theoretische Diskussion der 'gegenströmigen' Rückkehrbewegung erforderlich, da über diesen interessanten Komplex in der Migrationsforschung allgemein und auch in der Auswanderungsforschung speziell bislang zu wenig gearbeitet worden ist und nur wenige bruchstückhafte Forschungsergebnisse unterschiedlicher Orientierung vorliegen. Es wurde versucht, diese mehr sporadischen Ansätze zur theoretischen und empirischen Erfassung der Rückwanderung unter besonderer Berücksichtigung des deutschen und skandinavischen Raumes zusammenfassend zu berücksichtigen. Mit dieser grundsätzlichen Ausrichtung könnte die exemplarische Erfassung eines speziellen Rückwanderungsverlaufes, die in methodischer und inhaltlicher Hinsicht noch verfeinert werden muß, für die Forschung von allgemeinerem Interesse sein. Dadurch kann die Rückwanderung bei weiteren Untersuchungen der Überseewanderung als komplementärer Problemkomplex, der von den Herkunftsgebietes materialmäßig relativ gut zu bearbeiten ist, stärker bewußt gemacht werden." (Autorenreferat)

Description: Of 214 soil bacterial isolates able to reduce NO3-, 209 produced nitrous oxide (N2O), even though only 46 were respiratory denitrifiers (competent to carry out complete reduction of NO3- to N gases). Nitrite or NH4+ was the major product of NO3- reduction by the nondenitrifying organisms, but typically about 5 to 10% and up to 34% of the NO3- reduced by them was released as N2O during a 2-week incubation. Bacillus and Enterobacter were the most commonly observed genera of nondenitrifying N2O producers. Fermentative NO2- reduction and N2O production by a Bacillus sp. and a Citrobacter sp. were characterized in pure culture studies. Dinitrogen (N2) was not produced in detectable quantities by these organisms. When added to autoclaved soil, they accumulated more N2O than two denitrifying pseudomonads, since the latter consume and produce N2O. In tryptic soy broth (TSB), which allows active fermentative growth, NH4+ was apparently the major product of NO3- reduction. In nutrient broth (NB), NO2- accumulated. Added NH4+ did not inhibit N2O production or apparent reduction to NH4+, indicating that these processes are not assimilatory. The effect of added glucose on N2O production varied with the organism and media composition. Nitrous oxide production from NO2- by these organisms was shown to be at least partially a biochemical reaction. The N2O evolved slowly in batch cultures and mostly after apparent growth ceased. This is apparently a novel mechanism of N2O generation which differs significantly from respiratory denitrification.

Description: "Poseidon" lief arn 10. 10. 1982, 20.00 Uhr, von Ponta Delgada aus und begann die Arbeiten im Südostteil des Meßgebietes des 1. Fahrtabschnittes. Die relativ günstigen Wetterverhältnisse bis Mitte Oktober erlaubten die Vermessung des Wirbelfeldes bis 45° Nord. Anschliessend wurde der zentrale Bereich des Meßgebietes erneut untersucht und nach Südosten ergänzt. Während des Fahrtabschnittes wurden 129 XBT-Stationen und 16 Multisondenstationen durchgeführt. 4 im 1. Fahrtabscnnitt ausgelegte Driftbojen wurden aufgenommen. Dabei hat sich die Erweiterung der Funkstation sehr positiv ausgewirkt

Description: Für beide beteiligten Arbeitsgruppen (Chemie/Physik) diente die Reise im wesentlichen der Geräteerprobung für Forschungsfahrten im Frühjahr 1982. Daneben sollte mit Hilfe des Chemischen Profilers ein Profilschnitt durch das Kattegat in nordöstlicher Richtung auf Höhe Skagen aufgenommen werden, um Daten über die winterlichen Ein- und Ausstromverhältnisse zu gewinnen. Unterstützt wurden die chemischen Messungen durch Einsatz der Multisonde durch die physikalische Arbeitsgruppe.

Description: Neuere Entwicklungstendenzen und Perspektiven für die Zukunft

Description: An unusual stratigraphic unit (nicknamed “homogenite”) fills topographic lows in the complex ridge and trough bathymetry at two survey sites on the Western Mediterranean Ridge and the Calabrian Ridge. On near-bottom 4-kHz seismic-reflection profiles, this unit us an acoustically transparent, near-surface, flat-lying layer, whereas in cores, it is a homogeneous gray marl as much as 7 m thick. Grain size decreases upcore within the unit, implying that it was deposited in a single event controlled by gravitational settling. The stratigraphic position of the homogenite relative to a firmly dated sapropel bed suggests emplacement between 4400 and 3100 yr B.P. The source of the homogenite is inferred to be the nearby basin walls. Farther east, two other sites with similar rugged topography lack homogenite entirely. A triggering mechanism is required which is capable of initiating massive sediment transport simultaneously in many separate basins at the western two survey sites, but which is not effective at the eastern sites. A large archeologically recorded earthquake of the correct age is considered and rejected because its epicenter is closer to the nonhomogenite-bearing sites than to the sites where this sediment type was observed, and because several other earthquakes of comparable magnitude have since been recorded in the area, whereas the homogenite is unique. The 3,500 yr B.P. collapse of the caldera of the volcano of Santorini caused a huge tsunami which is recorded archeologically and geologically around the eastern Mediterranean. Because of refraction of the tsunami by the bathymetry, and because the caldera collapsed in its southwest corner, a disproportionate amount of tsunami energy was directed toward the western area where homogenite is observed. In contrast, the homogenite-free sites were relatively sheltered. An order-of-magnitude calculation shows that the near-bottom oscillating currents accompanying the Santorini tsunami were at or above the threshold erosion velocity at the homogenite-bearing sites. In addition, the near-bottom pressure pulse under the tsunami at the homogenite-bearing sites was sufficient to cause liquefaction of sediments. Neither mechanism was adequate to cause sediment transport or slope failure at the homogenite-free sites.

Description: A new species of the genus Ectothiorhodospira is described isolated from alkaline soda lakes of the Wadi Natrun in Egypt. In most of its properties it resembles the recently described Ectothiorhodospira halochloris, which had been isolated from similar lakes of the same area. The new species, Ectothiorhodospira abdelmalekii, has spiral-shaped cells with 0.9-1.2 μm diameter, it is polarly flagellated with sheated flagella, has lamellar photosynthetic membrane stacks, possesses bacteriochlorophyll b as the main photosynthetic pigment, and has a DNA base composition of 63.3–63.8 mol% G + C. Photolithotrophic growth with sulfide or elemental sulfur as electron donors is the predominant mode of life. During sulfide oxidation to sulfate, elemental sulfur is accumulated outside the cells. Acetate, pyruvate, fumarate and succinate are photoassimilated. The properties of E. halochloris and E. abdelmalekii are compared.

Description: Der fünfte Abschnitt der 76. Reise des F.S. "Poseidon" fand vom 10.-18.9.1981 im östlichen Nordatlantik statt

Description: Die 72. Reise der FS Poseidon fand zwischen dem 9. und 13. März 1981 im Skagerrak statt.

Description: Laboratory determinations of the distribution coefficient of strontium in calcite (k Sr ) have confirmed the earlier results of Katz et al. (1972). In addition, we observed that at higher concentrations of strontium, values of k Sr were somewhat lowered. Chemical analyses of several deep-sea carbonate sediment sections and their associated porewaters (DSDP Sites 288, 289, 315, 317, and 357) as well as previously published data of other workers (DSDP Sites 116 and 305) have been used to demonstrate that these k Sr values are appropriate for use in diagenetic studies. We have successfully modeled the distribution of strontium in the pore waters and sediments. As a result, we conclude that recrystallization of these carbonates (and many other limestones as well) is essentially isochemical, the cement being derived from within the formation. Advective fluid flow through the rock is unnecessary to explain its lithification. Recrystallization of the bulk of the calcite in deep-sea sections is largely complete within the upper few hundred meters, but cementation is generally a later process. These results have important implications for the study of oxygen isotopic compositions of foraminifers and coccoliths in many sediments older than about 20 m.y. B.P. From correlations between changes in Sr/Ca and Mg/Ca ratios of recrystallized carbonates of DSDP Site 305 a distribution coefficient of magnesium in calcite sediments of 8.1 x 10- 4 ( nearly equal 5 degrees C) has been estimated. This value is many times smaller than previously published values.

Description: OceanRep OceanRep Home Contact Quick Search Simple Search Advanced Search Browse Author Research division Document type Year Course of Study Latest Peer-reviewed Articles All About us GEOMAR Library Open Access Policies Statements Help FAQs Statistics Directions | Contact | Sitemap | Imprint Zur Kinematik eines stochastischen Feldes interner Wellen in einer Scherströmung. Logged in as Barbara Schmidt Manage depositsManage recordsManage shelvesProfileSaved searchesReviewAdminLogout - Tools Peters, Hartmut (1981) Zur Kinematik eines stochastischen Feldes interner Wellen in einer Scherströmung. (Doctoral thesis/PhD), Christian-Albrechts-Universität Kiel, Kiel, Germany, 118 pp. [img] Text Diss. 1981 Peters, H.pdf - Published Version Restricted to Registered users only Download (7Mb) Abstract Für die im Atlantik im Bereich des Äquatorialen Gegenstroms während GATE beobachtete mittlere Schichtung und Scherströmung werden vertikale Eigenschwingungen (Moden) und Dispersionskurven hochfrequenter (0.3 bis 15 cph) interner Wellen berechnet. Ein spektrales Modell der Kinematik freier, linearer interner Wellen wird durch die stochastische Überlagerung so gewonnener Moden erzeugt. Modellrechnungen werden zu Vergleichs- und Testzwecken für einfache Grundzustände (N 2 = const.; u = const.) durchgeführt. Die den Verhältnissen während GATE entsprechenden Rechnungen ergeben folgende Resultate: In den Energiespektren wird eine Schulter bei Frequenzen zwischen 1.5 und 4 cph beobachtet, die einen nicht unbeträchtlichen Teil der Gesamtenergie des Wellenfeldes repräsentiert. Diese Schulter kann im wesentlichen nicht durch kinematische Effekte erklärt werden, sie muß dynamische Ursachen haben. Im Frequenzbereich 1.5 bis 4 cph wird das Wellenfeld praktisch ausschließlich von der ersten Mode beherrscht. Nach den Beobachtungen sind die Wellen überwiegend gegen die mittlere Strömung gerichtet. Zur Erklärung dessen müssen sowohl dynamische als auch kinematische Effekte herangezogen werden. Das beobachtete Maximum der Kohärenz zwischen Strömung in der Deckschicht und Temperatur in der Sprungschicht zwischen 1. 5 und 4 cph ist prinzipiell der Kinematik des Systems zuzuschreiben. Die Skalen des Wellenzahlspektrums, die sich aus der Anpassung des Modells an die Daten ergeben, sind derart, daß nur ein Teil der Anisotropie des Systems von Moden und Dispersionskurven wirksam wird. Die Vertikalstruktur der beobachteten Strömungsfluktuationen kann mit dem Modell nicht vollständig beschrieben werden. Das Modell wird kritisch diskutiert.

Description: The Middle Triassic carbonate series of the Hochstaufen-Zwieselmassif reflect the last stage of a northward progradation of a wide southern reef platform extending into the attached northern basin. Regional facies differentiation was caused by differences in the morphology of the basin. A massive central reef core, exhibiting clear ecological zonation, developed along the slope of the slightly deeper eastern part of the basin. The shallower western parts, however, were quickly filled up by forereef debris and overlain by sediments of the rapidly spreading lagoon. A typical grapestone facies includes intercalations of vadose pisolitic crusts, thus indicating a shallow marine platform environment, which was sporadically interrupted by areas of subaerial exposure. Various sediment types occurring along the platform margin reflect synsedimentary mass movements. These were induced by tectonic disturbances caused by different rates of subsidence between the rapidly subsiding platform and the slowly subsiding basin. Forereef rocks which have been entirely lithified were affected by various stages of internal brecciation during this process. In contrast, basinal sediments which were semilithified or patchily cemented exhibit plastic deformation (slumping) and subsequent disintegration into intraformational breccias and debris flows. Turbidites were induced in cases of higher pore water saturations. All these mass mobilisations took place on gentle slopes. This assumption is supported by the observation of initial reef growth flourishing on protected areas of the foreslope. Along a gentle slope, differential rates of subsidence can easily be balanced by plastic deformation and dislocation of basinal material. This is supported by the fact that no prominent synsedimentary fault system could be observed along the platform margin. The facies differentiation of the central reef core is substantiated by a clear eclogical zonation of organisms. The lower, more protected portions of the central reef belt were occupied by theTubiphytes zones. Along the reef front the Coral-Solenoporacean biocoenoses found favorable living conditions. The high energy sediments of the reef flat exhibit a highly diverse Calcisponge—Hydrozoan—Coral community. Towards backreef areas a small belt was inhabited by a typicalThecosmilia —Thaumatoporella biocenosis. Die mitteltriadischen Karbonatserien des Hochstaufen-Zwieselmassives im Mittel-abschnitt des Alpennordrandes dokumentieren die jüngste Ausbreitungsphase einer ausgedehnten südlichen Riffplattform gegen ein nördlich vorgelagertes Becken. Die Entwicklung eines ausgeprägten Reliefs innerhalb des beckens verursachte eine starke regionale Faziesdifferenzierung. In den geringfügig tieferen östlichen Beckenabschnitten entwickelte sich ein Riffgürtel mit deutlicher Zonierung, während in den flacheren westlichen Beckenarealen über Vorriffsedimenten direkt eine lagunäre Entwicklung folgt. Zyklische Einschaltungen von vadosen Pisolitkrusten in eine überwiegende Grapestonefazies weisen den lagunären Ablagerungsraum als flachstmarine von zahlreichen Auftauchbereichen durchsetzte Plattform aus. Entlang des Plattformrandes dokumentieren zahlreiche Sedimenttypen synsedimentäre Massenbewegungen. Diese resultieren aus tektonischen Turbulenzen verursacht durch differentielle Absenkungsraten zwischen rasch absinkender Plattform und nur geringfügig absinkendem Becken. Diese Massenbewegungen führen in den vollständig lithifizierten Vorriffsedimenten zu unterschiedlichen Stadien von Internbrekziierung. Die meist nur partiell oder fleckenhaft zementierten Beckensedimente reagieren hingegen auf die gleichen Beanspruchung mit plastischer Deformation. Rutschfalten, intraformationale Brekzien. Debris Flows und schließlich proximale Turbidite dokumentieren zunehmende Deformation und Dislociierung. All diese Massenverlagerungen fanden entlang eines nur geringfügig geneigten Plattformabhanges statt. Dies wird durch das Aufblühen von initialem Riffwachstum in verschiedenen Abschnitten des Beckenabhanges dokumentiert. Aufgrund des geringfügigen Neigungswinkels des Plattformabhanges konnten die differentiellen Absenkungsraten im wesentlichen durch plastische Deformation und Massenverlagerung des Beckenmaterials aufgefangen werden. Daher kam es auch nicht zur Ausbildung von tiefreichenden Störungssystemen entlang des Plattformrandes. Die fazielle Differenzierung des Zentralriffbereiches korrespondiert mit einer ausgeprägten ökologischen Zonierung. Der untere geschütztere Abschnitt des Zentralriffgürtels wird von derTubiphytee-Zone eingenommen. Entlang der Riff-front etablierte sich eine Korallen-Solenoporaceen Biocoenose, während die hochenergetischen Sedimente des “reef flats” eine hochdiverse Kalkschwamm— Hydrozoen—Korallenvergesellschaftung aufweisen. Gegen das Rückriff folgt ein schmaler Gürtel mit einer typischen Thecosmilien-Thaumatoporellen Biocönose.

Description: The basement morphology and sediment thickness of the Hess Rise, an oceanic plateau in the central North Pacific, have been mapped on the basis of seismic reflection profiles. The acoustic stratigraphy on and around the rise is correlated with the lithostratigraphy at Deep Sea Drilling Project sites 464, 310, 465, and 466. A total sediment isopach chart of the rise reveals small-scale departures from the expected sedimentary pattern (thick sediment in shallow areas; thin sediment in deep areas). Sediment-filled basement depressions result from mass transport; thin sediment (〈50 m) occurs on steep scarps, basement ridges, and areas affected by bottom currents. A pre-Senonian sediment isopach chart shows a thickening from less than 50 m to more than 250 m of sediment from the northeast to the southwest. This trend seems explainable only in terms of the time-transgressive nature of seafloor formed at a mid-ocean ridge. The axial trend of the rise (N30°W) parallels nearby Mesozoic magnetic lineations and seems to be isochronous as deduced from the Deep Sea Drilling Project data. The Hess Rise began developing in late Aptian time along a segment of the Pacific-Farallon Ridge. Important events in the history of the rise are late-stage volcanism on the southern margin of the rise along the Mendocino Fracture Zone, tectonism and volcanism about 85 Ma that resulted in a major regional unconformity (reflector C), and another period of tectonism and volcanism between 65 and 43 Ma that coincided with the formation of the Emperor Seamounts and created structural benches on the western side of the rise. A significant change in the paleoenvironment that apparently occurred around the Paleogene-Neogene boundary (∼25–20 Ma) caused pronounced changes in the depositional environment and resulted in another major regional unconformity (reflector A).

Description: The vertically migrating squid, Abralia trigonura, has at least two types of photophores involved in counterillumination. The most complex of these is described. We suggest that this photophore functions in the following manner. Innervated photocytes which contain crystalloids extract a component of the luminous reaction, presumably luciferin, from blood vessels via numerous finger-like processes. Energy for the reaction is supplied by banks of mitochondrial cells. Light is emitted by the crystalloids which are stacked to form a photogenic cone. The photogenic cone lies at the focus of a spherical proximal reflector. This reflector is an interference structure that selectively reflects light outward and contributes to color regulation by the alteration of its reflectance characteristics through changes in the diameter of its Collagen rods. An interference filter, the axial stack, selectively transmits light and contributes to color regulation by altering the thickness of the fluid-filled spaces between its platelets.