ALBERT

Description: Benthic foraminifera from surface Sediments of the Ross Sea were studied to determine modern distributions of important assemblages. Factor analysis of the raw data distinguished nine significant factor assemblages which account for 86% of the raw data. These factor assemblages provide a means of understanding modern oceanographic and ecologic conditions because they show the response of this faunal group to different environments. Environmental conditions are in turn controlled by the modern climatic regime of the region. Four benthic assemblages from the relatively shallow (500 to 700 m) eastern Ross Sea Continental shelf are predominantly arenaceous. This may be because the relatively late seasonal breakup of pack ice inhibits productivity in the surface waters and permits a buildup of CO, thus causing the CCD to occur at shallow depths. On the Western part of the Continental shelf, three assemblages are composed primarily of calcareous species even though water depths are often greater there than they are in the east. One of these calcareous assemblages occurs in samples from water depths as great as 755 m in the southwestern part of the region, below the CCD as defined for the Ross Sea by previous workers. We relate this depressed CCD to early seasonal breakup of pack ice in the Western Ross Sea. Within the eastern arenaceous and Western calcareous regions on the Continental shelf, distributions of benthic assemblages are probably related to water depth and other ecologic variables. Two benthic assemblages from the Continental slope north of the Ross Sea also are calcareous. We attribute their distributions to high rates of productivity in the overlying surface waters, where the interface between eastward-flowing Circumpolar Deep Water and Ross Sea water masses is marked by a narrow zone of intense upwelling.

Description: Eine bei vielen küstenmorphologischen und sedimentologischen Untersuchungen interessierende Frage gilt der Sedimentbilanz. Da sie ein Produkt der lokalen topographischen und hydrologi­schen Komponenten ist und (bisher) nicht ohne weiteres vorher­sagbar, sind Messungen und deren Auswertungen für einzelne Gebiete von allgemeinem Interesse. Für die »Anse de Kernic«, eine Lagune im Bereich der sehr großen Gezeiten an der Nordküste der Bretagne (Abb. 1) wurden im Laufe mehrerer Jahre flächenmäßig Höhendaten zu­sammengetragen. Ihre Auswertung und vergleichende Gegen­überstellung werden im folgenden vorgestellt.

Description: The Lushanian Stage, now known to represent a greater part of the so-called Slate Formation in the Central Range of Taiwan, is essentially correlative with Blow's Zone N.8, including small parts of zones upward and downward, and is directly underlain either by the Discocyclina-Nummulites-bearing Pilushanian Stage or by older formations, the normally intervening Oligocene and Aquitanian being missing altogether.

Description: Stomach contents of 68 black petrels, Procellaria parkinsoni, 12 Westland black petrels, P. westlandica, and 3 white‐chinned petrels, P. aequinoctialis, were compared. The main prey were Cephalopoda and fish, and these indicated predominantly nocturnal feeding with selection for bioluminescent forms. There is marked latitudinal variation in the Cephalopoda available to these petrels.

Description: Using the fault plane mechanisms of the shallow earthquakes occurring along the Hellenic arc and the extent of the intermediate seismic belt, we make a quantitative estimate of the relative motion occurring between the Hellenic arc and the adjacent sea floor. This estimate is then used to evaluate the deformation in the Aegean area and to reconstruct the pattern of motion over the Eastern Mediterranean region for the last 13 m.y. It is shown that this pattern is compatible with the neotectonic and seismicity studies in Aegea. We then discuss the dynamics of the area and propose that, since Serravallian-Tortonian time, Aegea has been spreading gravitationally in front of the southwestward advancing Turkey. The reasons for this gravitational spreading are discussed.

Description: Since organic chemistry began, the chemistry of natural products from terrestrial organisms such as plants and fungi has been studied intensively; in contrast, marine species have received relatively little attention. However, in the last decade research in the field of marine products has increased sbstantially. The heightened interest in this area is attested by the appearance of the monumental treatise of Halstead on Poisonous and Venomous Marine Animals in 1965 (108), Baslow’s review on “Marine Pharmacology” in 1969 (14) and Scheuer’s recent book “Chemistry of Marine Natural Products” (160) in 1973. In addition Premuzic’s review devoted to the Chemistry of Natural Products Derived from Marine Sources, was published in volume 29 of this series in 1971 (152).

Description: Rowe proposed a stress–dilatancy relation for granular assemblies in a dense packing of the form Ė=tan2(¼π+½φμ). He used a minimum energy ratio principle to develop this relation. It is shown here that the same result is obtained by considering the same model of toothed separation planes as that treated by Rowe, and applying to that model the laws of friction only.

Description: The relatively high concentrations of cobalt, nickel, and copper in deep-sea manganese nodules, such as those occurring on the sea-bed beneath the north equatorial Pacific Ocean, indicate that these marine sediments are potential ore deposits. In order to explain the strong enrichments of Ni, Cu, and Co in the nodules, the crystal chemistries and structures of the host manganese oxide minerals must be understood. Over twenty manganese(IV) oxide minerals are known, but only three predominate in manganese nodules. They are todorokite, birnessite, and delta-MnO2. All MnIV oxides contain edge-shared MnO6 octahedra linked in diverse ways, leading to a hierarchy of structure-types somewhat resembling the classification of silicates. Todorokite is deduced to contain chains of edge-shared MnOe octahedra enclosing huge tunnels, thus resembling hollandite and psilomelane. Birnessite has a layered structure with essential vacancies in the sheets of edge-shared MnO6 octahedra, while δ-MnO2 is a disordered birnessite. The uptake of Co into manganese nodules involves replacement of low-spin Co3+ for Mn4+ ions in the structures, whereas Ni2+ and Cu2+ substitute for Mn2+ ions in octahedra located in the chains or between layers of edge-shared MnO6 octahedra.

Description: The spatial and temporal distribution and abundance of planktonic foraminifera in ocean waters are influenced by the interaction of biological factors (algal symbionts, food supply, predation, interfaunal relationships, productivity) and physical-chemical factors (nutrients, light, temperature, salinity, water density, turbidity, etc.). Estimates of standing stock have generally been obtained from plankton tows and not from total volumes of sea water. Size fractions less than 200μ have been ignored in most calculations of standing stocks, which usually increase by several orders of magnitude in progressively smaller size fractions. The relative abundance and distribution patterns of 32 species in Indian Ocean waters and surface sediments have been determined from 154 plankton tows and 190 core-tops. Principal-components analysis groups the populations into nine life assemblages and five fossil assemblages. A quantitative comparison between the life and fossil assemblages is then possible by algebraically relating the factor assemblages: FsFp× C The matrix of coefficients, C, shows the degree to which the spatially and seasonally independent plankton assemblages, Fp, are linearly mixed during the process of sedimentation to form the sea-bed assemblages, Fs. A large fraction of the sea-bed assemblages above the CaCO3 compensation depth may be derived by simple mixing of the plankton assemblages. The model shows, for example, how proportions of four discrete tropical and subtropical life assemblages contribute in producing a single tropical-subtropical fossil assemblage. According to this model, differential productivity, selective solution, and biotic mixing do not mark the primary distribution patterns of the living species.

Description: The observation of the loricas of Calpionellae by means of the Scanning Electron Microscope (S.E.M.) shows that their ultrastructure varies with the lithological nature of the fossilizing environment. We posit the hypothesis that - at the starting point - the walls of loricas consist of an only layer of small polyhedric crystals set side by side, uniform in diameter: 0,3 to 0,4 μ and arranged helicoidically. In the course of the diagenesis, three evolutions my occur: 1) in an argillaceous environment, initial crystallites grow into largesized crystals including the components of the surrounding stone (particularly coccolithes); 2) in an calcareous environment, the diagenesis leads to the formation of curved crystalline plates; 3) lastly, instead of growing, crystallites may undergo corrosion and cease to touch one another. They may even disappear.

Description: Data gathered by recent “Islas Orcadas” cruises reveal the seafloor spreading pattern for a region south of the Agulhas/Falkland fracture zone system. The presence of a magnetic anomaly bight about the Agulhas Plateau indicates that the Agulhas Plateau may have developed at the site of a tectonic plate triple junction during the Late Cretaceous. A westward jump in the seafloor spreading center during the Late Maestrichtian (anomaly 34−31) reduced the offset across the Falkland/Agulhas fracture zone system and resulted in the formation of two conjugate aseismic ridges here described as the Meteor and Islas Orcadas Rises. The magnetic lineation pattern in the Agulhas Basin suggests that a tectonic plate (Malvinas Plate) existed during Campanian to Maestrichtian times. Relative rates of motion are calculated for Antarctica, South America, and Africa for the Late Cretaceous.

Description: A sequence of ash layers recovered from site 178 of the Deep Sea Drilling Project in the Gulf of Alaska was studied to determine the nature of highly explosive volcanic eruptions associated with the Aleutian Arc and Alaskan Peninsula during the last 8 m.y. The major-element chemistry of 25 distinct ash layers was determined. When the analyses are plotted on conventional major-element variation diagrams, the unusual, highly evolved, calc-alkalic characteristics of the ashes are apparent. Perhaps more significantly, there is a good correlation of certain indices of the degree of chemical evolution of each ash (SiO2 content and Larsen index) with sample age. Both parameters vary cyclically, with maximum values of both indices occurring at present, 2.5, and about 5.0 m.y. ago. The cause of the cyclic activity, as well as discontinuous volcanic activity reported for other areas by other investigators, is not precisely known. However, we suggest that variable rates of subduction provide a viable hypothesis for discontinuous volcanic activity associated with convergent plate boundaries.

Description: Probabilistic analysis applied to stratigraphic data of a restricted locale yields the sequential relations between the species present. Thirteen sections containing calcareous nannofossils of Late Paleocene and Early Eocene strata of California were analysed to test this method. The lowest occurrence and the highest occurrence of each of 144 species were integrated into one probabilistic analysis. The results produce a sequence of occurrence of high reliabiliry and usefulness.

Description: Some of the basic assumptions implied in the theory of limiting similarity of coexisting competitors were investigated experimentally in the case of three congeneric, deposit feeding snails. The species show character displacement with respect to size when coexisting. In experimental containers with a natural substrate, interspecific, exploitative competition between snails of the same size range is as intense as intraspecific competition. Diatoms of a given size range, which constitute the most important food, show a "logistic" growth response to grazing, and individual growth of the snails is linearly related to diatom density. The previous observation that the snails show size dependent selection for ingested particle sizes is extended to show that this mechanism leads to a real resource partitioning between snails of different sizes. Size frequency distribution of diatoms in the sediment is a function of the sizes of grazing snails. Size selection of ingested sand grains may also be significant for resource partitioning since the migration rate of the attached microflora between sand grains seems to be slow relative to its growth on the individual sand grains.

Description: THE rare deep-sea octopod Cirrothauma murrayi Chun 1910 was first described from a single specimen caught during the Michael Sars Expedition of 1910 (ref. 1). Until now it has been caught only four more times2. We describe here three specimens of this species that were recently caught during biological cruises of RRS Discovery (Fig. 1). All of these animals, including the Discovery ones, have been caught at depths of more than 1,500 m, except one that was dip-netted through the ice of the Arctic Ocean3.

Description: A single layer of cells secretes the hard cephalopod beaks. The beccublasts are tall columnar cells that separate the beak from the surrounding buccal muscles, and must serve to attach these muscles to the beak. Within the cell layer there are three types of cells. The first, and most frequently found contain cell-long fibrils. These fibrils may have contractile and tensile properties. Complex trabeculae extend from the beccublasts into the matrix of the beak. The fibrils are attached to these trabeculae and at the other end of the cells they are anchored near to the beccublast-muscle cell interface, closely associated with the muscles that move the beak. The second group of cells contain masses of endoplasmic reticulum the cysternae of which are arranged along the long axis of the cell. These cells also contain dense granules and are probably the major source of beak hard tissue. It is probable that each cell secretes its own column of beak hard tissue. The third group of cells contains a mixture of fibrils and secretory tissue. In the beccublast layer there are changes in the proportion of the three types of cells depending upon the region sampled. In the region where growth is most active there are mostly secretory cells, whereas near the biting and wearing tip there are mainly anchoring type cells.

Description: We present a plate kinematic evolution of the South Atlantic which is based largely on the determination of the equatorial fracture zone trends between the African and South American continental margins. Four main opening phases are dated by oceanic magnetic anomalies, notably MO, A34, and A13, and are correlated with volcanism and tectonic events on land around the South Atlantic Ocean. The Ceara and Sierra Leone rises are probably of oceanic origin and were created 80 m.y. ago or later in their present-day positions with respect to South America and Africa.

Description: THE Sierra Leone Rise, located in the east equatorial Atlantic, forms a discontinuous chain of seamounts as shallow as 2 km extending with a general NE–SW trend from near the Sierra Leone coast of Africa, to the St Paul fracture zone near the Mid-Atlantic Ridge (Fig. 1). The origin of this feature has remained a topic of discussion. Sheridan et al.1 have hypothesised that the Sierra Leone Rise is a volcanic structure formed at the beginning of the opening of the Atlantic in the early Cretaceous period. The twin features of the Sierra Leone and the Ceara Rises are probably of oceanic origin and were created 80 Myr ago or later in their present-day position with respect to Africa and South America2. The Atlantic ocean exhibits several similar aseismic structures which appear symmetrically oriented with respect to the mid-oceanic ridge, such as the Walvis–Rio Grande Rise and the Iceland Faeroes–Iceland Greenland Ridges. These structures are volcanic edifices having a composition similar to that found in their associated islands3–7. Deep sea drilling of the Ceara Rise8,9 penetrated a basaltic basement of the upper Cretaceous period (Maestrichtian) (Leg 39, Site 354). Similarly, a DSDP hole (Leg 41, Site 366) on the Sierra Leone Rise, penetrated sediments of the same period, without reaching basement10. We report here the discovery of alkali-rich volcanics in an area of the Sierra Leone Rise. The sediment overlying the rock fragments is aged ∼45 Myr.

Description: Laboratory data are presented on the distribution of cobalt between pyrite, chalcopyrite, and pyrrhotite. Pyrite-type deposits are used to show that the results enable one to estimate the temperatures of formation for copper mineralization. Recent years have seen extensive studies on element distributions between coexisting minerals in order to define mineralogical thermometers and barometers [1-3]. Detailed studies have been made of the thermodynamic basis of such distributions, as well as of the factors that influence component levels in coexisting minerals. Here we will not consider a theoretical analysis of the distribution, but we do note that trace elements appear in pyrite and chalcopyrite only below the 1 wt. % level, while the compositions of the minerals deviate only slightly from stoichiometric, with temperature the main parameter that controls the distribution.

Description: This study is based on a reconstruction of the paleogeographic and paleobathymetric history of the South Atlantic and on a standardized set of sediment and biostratigraphic data from all Deep Sea Drilling Project sites. Standard data sets used are the lithologic description, biostratigraphic age, CaCO3 content, carbonate and carbonate-free sedimentation rates corrected for compaction, and hiatus distribution. For each site the subsidence history has been determined. Paleoceanographic variables used are the spatial and temporal lithofacies distribution, history of calcite compensation depth, surface fertility and lyocline, erosional events, and special lithologies (black shales). During its early history the South Atlantic consisted of a narrow rift divided by the Rio Grande Rise- Walvis Ridge barrier into a restricted northern and an open (to the southern ocean) southern basin. In the northern basin, evaporites are the earliest known marine sediments (Aptian) while more normal pelagic deposits formed in the southern basin. Free circulation of surface water between the southern ocean and the North Atlantic became possible late in the Mesozoic or in the early Cenozoic, and deep circulation (below 3 km depth) paths were open from north to south by the early Cenozoic. During the early and middle Mesozoic the South Atlantic had its own oceanographic character with dominantly terrigenous sedimentation and two anoxic black mudstone phases (Albian and Santonian) probably resulting from a strong oxygen minimum in mid-water caused by either excess surface fertility or old, slow moving bottom water. In the late Cretaceous the South Atlantic became part of the world ocean system and global events have overshadowed local ones since that time. After the early phase of rapid sedimentation of terrigenous material, the depositional history has been in- fluenced mainly by the increasing width and water depth of the basin and by fluctuations of the level and intensity of carbonate dissolution. At the Eocene/Oligocene boundary, the onset of a deep water circulation dominated by a cold circum-polar source of surface water is clearly marked by erosional events, a sharp drop of the calcite compensation depth and the arrival of biogenic siliceous oozes in the Argentine Basin.

Description: Estimation of average Cenozoic sedimentation rates for the Atlantic, Indian, and Pacific oceans indicates global synchronous fluctuations. Paleocene-early Eocene and late Eocene-early Miocene rates are only a fraction of middle Eocene and middle Miocene-Recent rates. These changes must reflect significantly different modes of continental weathering, which may be due to alternate states of atmospheric circulation marked by reduction of global precipitation.

Description: This chapter discusses the carbon turnover, calcification, and growth in coral reefs. Carbon turnover within a total reef community is a function of two distinct, biochemically interacting cycles. The first is the metabolic cycle consisting of the photosynthetic fixation of CO2 and the release of CO2 by respiration and decomposition processes. Superimposed on this are the direct incorporation of organic compounds (dissolved or particulate; living or non-living) originating outside the reef systems (in the adjacent ocean waters), and the loss of organic compounds from the reef system into the out-flowing water. The second is the inorganic carbonate cycle involving the biological and non-biological precipitation and dissolution of carbonates. Superimposed on this is the loss of particulate carbonates in suspension in the out-flowing water. The main chemical component of a coral-reef system is calcium carbonate, which occurs either as high-Mg calcite, aragonite, or low-Mg calcite. The mean calcification values in various environments at One Tree Reef are presented in the chapter. These data may be converted to an implied vertical growth rate potential assuming that accrual is dominantly aragonite (density = 2.89 g cm–3) and that there is 50% porosity after normal compaction.

Description: This paper concerns the linear response of the ocean to forcing at a specified frequency and wave number in the absence of mean currents. It discusses the details of the forcing function, the general properties of the equations of motion, and possible simplifications of these equations. Two representations for the oceanic response to forcing are described in detail. One solution is in terms of the normal modes of the ocean. The vertical structure of these modes corresponds to that of the barotropic and baroclinic modes; their latitudinal structure corresponds to that of inertia‐gravity and Rossby waves. These waves are eigenfunctions of Laplace's tidal equations (LTE) with the frequency as eigenvalue. The description in terms of vertically standing modes is particularly useful if the forcing is nonlocal, because only these modes can propagate into undisturbed regions. The principal result is that it is extremely difficult for baroclinic (but not barotropic) disturbances to propagate horizontally away from a forced region. Instabilities of the Gulf Stream excite disturbances that are confined to the immediate neighborhood of the current; disturbances due to instabilities of equatorial currents do not propagate far latitudinally. A second representation of the oceanic response to forcing is in terms of vertically propagating, or vertically trapped, latitudinal modes. These modes are eigenfunctions of LTE with the equivalent depth h (not the frequency) as eigenvalue. Both positive and negative eigenvalues h are necessary for completeness. The modes with h 〉 0 consist of an infinite set of inertia‐gravity waves and a finite set of Rossby waves which either propagate vertically or form vertically standing modes. The latitudinally gravest modes are equatorially trapped and have been observed in the Atlantic and Pacific oceans. The modes with h 〈 0 are necessary to describe the oceanic response to nonresonant forcing. In the vertical this response attenuates with increasing distance from the forcing region. Because of the shallowness of the ocean the large eastward traveling atmospheric cyclones in mid‐latitudes and high latitudes force a response down to the ocean floor. Interaction with the bottom topography will result in smaller‐scale disturbances and will affect the frequency spectrum of the response when bottom‐trapped waves are excited.

Description: Tidal currents and waves have caused some reworking and redistribution of Holocene sediments in the northern North Sea, with preferential deposition of fines in topographic depressions. This has led to a patchy distribution of sediments in terms of their textural, mineralogical and chemical composition. Nevertheless discernable relationships are found to exist between mean grain size and composition of the sediments. The relative abundance of biogenic components (primarily benthic Foraminifera) in the sand-size fraction of the sediments increases as mean grain size decreases, thus biogenic components are relatively more abundant in bathymetric lows. Coarse-grained sediments rich in detrital quartz show higher values of Si/ AI than do fine-grained sediments. Smectite is concentrated in the finest-grained sediments, whereas illite is relatively more abundant in coarser deposits. Thus clay mineral segregation processes previously reported to occur near river mouths also occur in an open shelf environment. Fine-grained, smectite-rich sediments show correspondingly higher values of Fe/ AI and lower values of K/ AI compared to the coarser deposits enriched in illite.

Description: Coastal marine sediments from different environments were investigated for natural radiocarbon isotope concentration: from the Fladenground area(northern North Sea), from the tidal flats off the western coast of Schleswig-Holstein, northern Germany, from Kiel Bight(western Baltic Sea), and from the Bornholm Basin(southern Baltic). Sediment sampling, pretreatment, and wet oxidation technique with sedimentary organic carbon are outlined. Organic matter as well as carbonates of coastal marine sediments are found to be composed of differently aged fractions. Sediment surface ages range between 800 years in the Baltic and 5000 years in the Fladenground area. In spite of these redistribution effects, however, the effective 14 C-age of the sediments is highly reproducible for a given environment. Minor variations are caused by varying supply of recent organic matter. In recent time dead carbon from fossil fuels and man-made 14 C from the nuclear weapon tests have entered the sedimentary environment ("ash-effect" and "bomb-effect"). For the Bomholm sediments the age composition of the organic matter could be analyzed in greater detail. The recent carbon fraction varies by a factor of 2.6 during the last 70 years, from 0.5% to 1.3% of sediment dry weight, and may be as low as 10% of total C-org content. The "eroded" fraction amounts to 3.6% of dry weight, the effective age being about 1500 years, and fossil fuel carbon is about 0.2% to 0.3% on dry weight basis.

Description: Paleogene and Neogene world-wide distribution patterns of planktonic foraminifera are discussed. Differences in environmental conditions, mainly changing water temperatures, are regarded as the principal factors controlling the occurrence and distribution of individual species. Species associations caused by natural barriers, such as the Isthmus of Panama, may also develop at similar latitudes. Furthermore, anomalous distribution patterns, resulting from the exclusion of certain species at the expense of others are also known within the same area. As a result of all these differing species distributions numerous zonal schemes were proposed, some of which are herein shown on figures 1 and 6. Correlation problems that necessarily arise from this are discussed for a number of selected areas and sections. For the Paleogene, examples are discussed from the Caucausus-Crimea and eastern Mediterranean, where faunal differences are caused by climatic and facies changes. In the Neogene of the Caribbean-Atlantic and Indo-Pacific, different faunal developments and distribution patterns may occur at similar latitudes. A good example of temporary exclusion of certain species is found within the Caribbean, where during the presence of Globorotalia miocenica Palmer, G. exilis, and G. pertenuis Beard in the Middle Pliocene, Pulleniatina sp. and to a large degree also Globorotalia menardii (d'Orbigny) have disappeared, to return only after the extinction of the first named group of species.

Description: A preparation of the mantle of Octopus which is inverted over a solid support and which exposes the stellate ganglion and associated nerves is described. 2. Afferent activity can be recorded from stellar nerves following electrical stimulation of the pallial nerve. The latency and frequency of the phasic sensory response is correlated with the contraction of the mantle musculature. 3. It is proposed that receptors cells located in the muscle, and their activity following mantle contraction, form part of a sensory feedback system in the mantle. Large, multipolar nerve cells that were found between the two main layers of circular muscle in the mantle could be such receptors.

Description: A reexamination of all available palaeopalaemonid specimens, of the genus Palaeopa- laemon, and material of Bellocaris newfoundlandensis Fong, 1972, is presented. The four described species of Palaeopalaemon are synonymized as one, P. newberryi Whitfield, 1880. A detailed study of the anatomy leads to the conclusion that P. newberryi is the earliest recognized decapod eucarid crustacean with characters of both the glypheoidean palinurans and astacideans. Bellocaris is not a paleopalaemonid but a pygocephalomorph mysidacean peracarid, closely related to Pygocephalus.

Description: Geophysical data collected during a detailed survey in Baffin Bay have shown that lineated magnetic anomalies trending north-northwest occupy the deep central region. These anomalies exhibit maximum amplitudes of about 300 nT and can be modelled by a 1-km thick magnetic source layer divided into blocks of normal and reversed polarity. The magnetizations required are comparable with those of oceanic basalts. A striking feature of the gravity field is a 20 mGal gravity low, about 20 km wide, which runs through the centre of the bay with approximately the same trend as the magnetic lineations. The gravity low is associated with a change in crustal structure measured from seismic refraction data and sometimes with a deepening of the sediment-basement interface, reminiscent of a median valley. These results suggest that the magnetic anomalies were produced by sea-floor spreading and that the gravity low marks an extinct spreading centre in Baffin Bay. Comparisons of the magnetic anomaly profiles with a model profile computed for magnetic anomalies 13–24 (38 to 60 Ma), show good correlation between the observed and computed anomalies in the time period represented by anomalies 13–21, with slow spreading rates of about 0.3–0.4 cm yr−1 perpendicular to the spreading axis. These results are in reasonable agreement with magnetic anomaly identifications and spreading rates deduced from geophysical data in the Labrador Sea. The direction of plate motion in Baffin Bay is not well defined from the data, but the Labrador Sea data require plate motions at a highly oblique angle to the spreading centre in the bay. Peculiarities of the postulated spreading centre, including the change in crustal structure beneath the gravity low along its strike from south to north, and the decrease in coherence and amplitude of the magnetic anomalies immediately north of the survey area, may be the result of these very low spreading rates, oblique spreading and changes in spreading direction, or the proximity of this area to the junction with a possible major transform fault through the Nares Strait.

Description: Length-mass relationships, the water content and energy values are given for two species of squid commonly eaught in bottom trawls off the South-Western Cape. The data are of use in assessing the effect of predators on squid Stocks.

Description: A tsunami earthquake is defined as a shock which generates extensive tsunamis but relatively weak seismic waves. A comparative study is made for the two recent tsunami earthquakes, and a subduction mechanism near a deep-sea trench is discussed. These two earthquakes occurred at extremely shallow depths far off the coasts of the Kurile Islands and of eastern Hokkaido on October 20, 1963, and on June 10, 1975, respectively. Both can be regarded as an aftershock of the preceding larger events. Their tsunami heights and seismic wave amplitudes are compared with those of the preceding events. The results show that the time constants involved in the tsunami earthquakes are relatively long but not long enough to explain the observed disproportionality between the tsunamis and the seismic waves. The process times are estimated to be less than 100 s. The spatio-temporal characteristics of the two events suggest that they represent a seaward and upward extension of the rupture associated with a great earthquake which did not break the free surface at the coseismic stage. The amplitude and phase spectra of long-period surface waves and the long-period P waveforms indicate that this extension of the rupture did not take place entirely along the lithospheric interface emerging as a trench axis. It rather branched upward from the interface in a complex way through the wedge portion at the leading edge of the continental lithosphere. This wedge portion consists in large part of thick deformable sediments. A large vertical deformation and hence extensive tsunamis result from such a branching process. A shallowest source depth, steepening of rupture surfaces, and a deformable nature of the source region all enhance generation of tsunamis. The wedge portion ruptured by a tsunami earthquake is usually characterized by a very low seismic activity which is presumably due to ductility of the sediments. We suggest that this portion fractures in a brittle way to generate a tsunami earthquake when it is loaded suddenly by the occurrence of a great earthquake and that otherwise it yields slowly. Upward branching of the rupture from the lithospheric interface produces permanent deformation of the free surface which is relative uplift landward and relative subsidence trenchward of the zone of surface break. This surface break zone geomorphologically corresponds to the lower continental slope between the deep-sea terrace and the trench. Such a mode of permanent deformation seems to be consistent with a rising feature of the outer ridge of the deep-sea terrace and a depressional feature of the trench. This consistency implies a causal relationship between great earthquake activities and geomorphological features near the trench.

Description: A tsunami earthquake is defined as a shock which generates extensive tsunamis but relatively weak seismic waves. A comparative study is made for the two recent tsunami earthquakes, and a subduction mechanism near a deep-sea trench is discussed. These two earthquakes occurred at extremely shallow depths far off the coasts of the Kurile Islands and of eastern Hokkaido on October 20, 1963, and on June 10, 1975, respectively. Both can be regarded as an aftershock of the preceding larger events. Their tsunami heights and seismic wave amplitudes are compared with those of the preceding events. The results show that the time constants involved in the tsunami earthquakes are relatively long but not long enough to explain the observed disproportionality between the tsunamis and the seismic waves. The process times are estimated to be less than 100 s. The spatio-temporal characteristics of the two events suggest that they represent a seaward and upward extension of the rupture associated with a great earthquake which did not break the free surface at the coseismic stage. The amplitude and phase spectra of long-period surface waves and the long-period P waveforms indicate that this extension of the rupture did not take place entirely along the lithospheric interface emerging as a trench axis. It rather branched upward from the interface in a complex way through the wedge portion at the leading edge of the continental lithosphere. This wedge portion consists in large part of thick deformable sediments. A large vertical deformation and hence extensive tsunamis result from such a branching process. A shallowest source depth, steepening of rupture surfaces, and a deformable nature of the source region all enhance generation of tsunamis. The wedge portion ruptured by a tsunami earthquake is usually characterized by a very low seismic activity which is presumably due to ductility of the sediments. We suggest that this portion fractures in a brittle way to generate a tsunami earthquake when it is loaded suddenly by the occurrence of a great earthquake and that otherwise it yields slowly. Upward branching of the rupture from the lithospheric interface produces permanent deformation of the free surface which is relative uplift landward and relative subsidence trenchward of the zone of surface break. This surface break zone geomorphologically corresponds to the lower continental slope between the deep-sea terrace and the trench. Such a mode of permanent deformation seems to be consistent with a rising feature of the outer ridge of the deep-sea terrace and a depressional feature of the trench. This consistency implies a causal relationship between great earthquake activities and geomorphological features near the trench.

Description: Methods used for the solution of hydrodynamic governing equations in numerical models of the atmosphere are discussed. In particular grid point finite difference methods and problems and methods used for time and horizontal space differencing are covered. Specific problems relating to the numerical solution of the advection and gravity wave equations are discussed. Volume 1

Description: Intracellular and extracellular recordings from the stem, gastrozooids, palpons, tentacles and nectophores of physonectid siphonophores are presented. The stem organization previously described for Nanomia applies with only minor differences to Forskalia and Agalma. The endodermal epithelium of the stem is shown to be the pathway for slow potentials. Pumping cycles and feeding activities are organized locally in gastrozooids and palpons. Protective retractions are coordinated, probably through a direct nervous link with the stem. This is also true of tentacles. The ectoderm of bracts is a conducting epithelium; excitation in it can induce nervous activity in the stem, but the mechanism is unknown. Impulse traffic between stem and zooids is erratic and breaks down rapidly with repeated stimulation. The motor centres of the nectophores are connected to the stem by a labile nervous link, but an alternative epithelial pathway exists.

Description: Early investigators, Verrill, Baird, Leidy, and others, studied the marine fauna of the Atlantic coast of North America, They reported developmental stages of tapeworms in various invertehrates and in lishes. Morphological agreement of plerocercoids from the several host-species presaged taxonomic relationship but posed an enigma: the presence of similar larvae in such diverse host-species. No Information on life-histories of marine cestodes was available, and determination of life-cycles under experimentally-controlled conditions was far in the future.

Description: Six spinose species of planktonic foraminifera (Hastigerina pelagica (d'Orbigny), Globigerinella aequilateralis (Brady), Globigerinoides ruber (d'Orbigny), Globigerinoides sacculifer (Brady), Globigerinoides conglobatus (Brady) and Orbulina universa d'Orbigny) are routinely collected by scuba diving in the Sargasso Sea off Bermuda and are maintained in the laboratory. These and non-spinose species can also be collected with plankton nets for laboratory culture. H. pelagica recovers extremely well from the net-towing operation. The mean survival times of H. pelagica, G. aequilateralis, G. ruber, G. sacculifer, G. conglobatus and O. universa in laboratory cultures are 21.1, 10.6, 6.2, 6.7, 11.8 and 8.8 days, respectively. These figures reflect in part the onset of gametogenesis, which terminates the life of the mother cell. During gametogenesis, which occurs over a period of about thirteen hours, the mother shell sinks and sheds its spines, and hundreds of thousands of gametes are released. Gametogenesis has been observed in nine species. All six spinose species possess one or more types of associated algae, which vary widely in size and number. The external ones are large dinoflagellates, such as Pyrocystis fusiformis, P. noctiluca and Dissodinium spp., which occur with H. pelagica. The smaller ones (zooxanthellae) in G. sacculifer, G. ruber and O. universa exhibit a circadian periodicity of ingress into the shell in the evening and egress to the rhizopodial network and the distal parts of the spines during the day. Some planktonic foraminiferal species are herbivorous, others are carnivorous, and still others are omnivorous. Copepods appear to be the main diet of G. aequilateralis and H. pelagica, both of which are fed Artemia nauplii in the laboratory. Shell and spine growth have been observed, and the formation of a new chamber in G. ruber takes place in about 90 minutes.

Description: Length distribution and reproductive biology of Illex argentinus in the Argentine Sea.(April 1978-April 1979). Size measurements of 13,989 specimens of Illex argentinus were made by japanese scientists on board of the R/V "Shinkai Maru", during the exploratory cruise carried out by that ship in the Argentine Sea from April 1978 to April 1979. Samples were analyzed by the author on land, with determination of size, sex and maturity stage.

Description: A heavy mineral study in Grays Harbor, Washington, was undertaken to determine the sources and dispersal patterns of sands in the estuary. Using conventional heavy mineral analysis three provinces of sand deposition were clearly outlined: marine, mixed and river. Sands with a heavy mineral suite characteristic of the marine province extend more than 11 km into the estuary, suggesting that the lower part of the estuary is being filled by marine sands. The results of this study suggest that routine heavy mineral analysis of sands in estuaries may have much practical importance to those interested in predicting the long term directions of dispersal of sands that may be dumped in the estuary as a consequence of dredging activity.

Description: Afferent activity in the stellar nerves of Octopus vulgaris has been recorded in response to a probe applying a mechanical stimulus of approximately 5 gm/mm2 to the inner surface of the mantle. Mechanical sensitivity is distributed throughout the mantle surface and there is a large degree of overlap between the peripheral fields of nearby stellar nerves but no overlap of either ventral or dorsal midline. The afferent activity probably results from stimulation of sensory receptors located in the mantle and skin, but antidromic discharge in motor fibres is also possible.

Description: Great Belt, Vejsnäs Rinne and Boknis Rinne form a major interconnected channel System of approximately 80 km length and 30 m depth on the Kiel Bay sea floor, which generally is only some 10 to 20 m deep. 1971 to 1973, 32 transects were sampled across the channel slopes using narrow Station distances and systematically adding data (T°, S°/oo) from 5 hydrographic cross sections over a one and a half year period. A quantitative, combined study of the molluscan fauna, dead shells and Sediments yielded the following results. 30 species of bivalves and 19 of gastropods were sampled as livingspecimens. According to their long life span, Cypritta islandica is dominant in the deep and the Astarte species on the upper part of the channel slope. Macoma baltica is dominantin a third, more shallow Zone, which is actually outside of the channels. Abra alba is the most persistent species of the channels being present in 86% of all samples. Except for Hydrobia, gastropods display low numbers of presence and abundance and are almost never dominant. The bottom level of the thermohaline pycnocline impinges on the channel slope as a rule between (15-)18 and 22 (-25) m depth. This boundary layer is clearly reflected by the fauna, i.e. by maximum numbers of species and species richness, of species presence and abundance, as well as of the biomass of total molluscs and of most of the single mollusc species. The faunal Optimum is explained by the favourable combination of a suite of factors, such as relatively stable temperatures and increased salinity, sufficient aeration, and a strong “rain” of larvae and nutrition where the upper water mass is barred by the pycnocline. Substrate conditions (± 50 % of Sediment 〈 63 p) might be favourable as well. The deeper water mass of the channel System is increasingly plumbed by the pycnocline and correspondingly poor in oxygen concentration towards the inner end of the bay. The oxygen deficiency more and more confines the Optimum beit of the molluscs from below, and causes a distinct elevation of the maximum numbers of species, species richness, species dominance and biomass from the entrance towards the inner part of the bay from 20-24 to 15 -20 m depth. Increasing distance from the bay ’s entrance , (the Great Belt) does not exert any other influence on the molluscan fauna. Averaging the whole transects, the mean numbers of species, species richness, species presence and biomass stay constant in line with constant T-S conditions. The molluscan Optimum belt is widened on the slope towards the deep and partly doubled at current and water exposed parts of the slope, where it also achieves its absolute maximum numbers. No molluscan species is bound to a specific type of Sediment, though eventually certain Sediments may be preferred. Mud forms an exception in showing a clear decrease of the number of specimens (by an overlap with the factor oxygen deficiency). Except for the well known general reduction of species in the Kiel Bay, the distribution pattern of temp erature and salinity exerts only minor influences on the fauna. The dead-shell species as semblage generally reflects the living one. On the whole, they correspond with their composition of species, the zonation of dominant species (middle, emergent Astarte beit) and the distribution and elevation pattern of the maxima of species, species richness and dead-shell quantities. A downslope transport of shells is inferred, among other things, from a stronger presence of (dead-shell) species in the deeper part of the channel. As measured by the lateral displacement of the mollusc maximum belts, the transport amounts 1 to 3 m in vertical distance, rarely up to 7 m at current exposed slopes. These numbers correspond to 30-75 m horizontal distance. Besides currents, extreme wave action is a possible cause. Current induced long-distance transport of dead shells generates increased numbers of species, species presence and dead-shell quantities at the channel bottom, especially behind narrow passes. Hotvever, taking into account the undisturbed distribution of dominant species, the quantity of reworked shells must be insignificant. First indications of the shell production can be derived from the living-dead ratio of shell samples — notwithstanding the varying amounts of carbonate dissolution. For instance, the production of Astarte species is some 13 times smaller than the one of Abra alba and 7 times smaller than that of Cyprina islandica. — A general strong change from living to dead-shell dominance occurs below the pycnocline at 20 to 24 m depth. In the case of a fossil analogue of a Baltic Sea channel, marked shell horizons with a broad species spectrum most probably correspond to a molluscan zone at the level of the mean pycnocline Position.

Description: Mass occurrences of the blue-green algae Aphanizomenon flos-aquae and Nodularia spumigena have been observed more often in the Baltic proper during the last few years. The present paper touches on some questions connected with the mass production of Cyanophyceae, such as the origin of the blue-green algae blooms, their limitation by nutrients, their nitrogen fixation and their role as nitrate suppliers. The agglomeration of blue-green algae is shown to be a biotic community, and some relations of these algae in the food web are examined. Some results of in sitt1 experiments and recent laboratory investigations are given.

Description: The ommastrephid squids are large active animals occurring in most of the world's oceans. Luminous organs or bioluminescence have been observed only in members of the subfamily Sthenoteuthinae, containing the genera Ornithoteuthis, Symplectoteuthis (= Eucleoteuthis), Hyaloteuthis, Ommastrephes and Dosidicus. The light organs of Ommastrephes pteropus are small sub-spherical bodies randomly distributed over the ventral surface of the mantle, head, arms and tentacles (Roper, 1963) and are aggregated dorsally to form a large luminous patch (Clarke, 1965). Relatively little is known about the organs, capabilities and biochemistry of luminescence in cephalopods (Harvey, 1952; Herring, in Press), and the size of the light organ and availability of O. pteropus provide an unusual opportunity for such studies. Although among the molluscs the luminescent systems of the gastropod Latia and the bivalve Pholas have been partially characterized (Shimomura & Johnson, 1968; Henry, Isambert & Michelson, 1970, 1973) the only cephalopod system which has been investigated to date is that of the enoploteuthid Watasenia scintillans (Goto et al., 1974; Inoue et al., 1975). This investigation examines the anatomy and biochemistry of the dorsal light organ of O. pteropus, which differs markedly in these respects from the brachial organs of Watasenia.

Description: Squids (teuthoids) fall into two distinct groups according to their density in sea water. Squids of one group are considerably denser than sea water and must swim to stop sinking; squids in the other group are nearly neutrally buoyant. Analyses show that in almost all the neutrally buoyant squids large amounts of ammonium are present. This ammonium is not uniformly distributed throughout the body but is mostly confined to special tissues where its concentration can approach half molar. The locations of such tissues differ according to the species and developmental stage of the squid. It is clear that the ammonium-rich solution are almost isosmotic with sea water but of lower density and they are present in sufficient volume to provide the main buoyancy mechanism of these squids. A variety of evidence is given which suggests that squids in no less than 12 of the 26 families achieve near-neutral buoyancy in this way and that 14 families contain squids appreciably denser than sea water [at least one family contains both types of squid]. Some of the ammonium-rich squids are extremely abundant in the oceans.