ALBERT

Description: 1. 52 species of Crustacea Decapoda Reptantia, one of which new, were obtained on the cruises of R. V. "Meteor" dealt with in this paper. 2. The status of Euchirograpsus liguricus and E. americanus is discussed in some detail. It is shown that E. americanus is restricted to the western Atlantic, while E. liguricus occurs only in the eastern Atlantic. Records of E. americanus outside the western Atlantic are due to confusions with E. liguricus or other new species which have been described elsewhere (TÜRKAY 1975). 3. 3 species ( Polycheles crucifera, Munida iris ruttlandi, Cymonomus normani) are recorded for the first time from the Portuguese and 4 species ( Polycheles granulatus, Munida iris ruttlandi, Jaxea nocturna1, Macropipus rugosus) from the Moroccan coast. 4. The characterization of the Moroccan and Lusitanic province may be performed quantitatively rather than qualitatively. Further investigations are needed in order to get complete results.

Description: This paper deals with Euphausiacea collected in the upwelling region off Northwest Africa between Cap Blanc and Cap Mirik (Timiris) during the voyages 19 (1970) and 26 (1972) of the research vessel "Meteor". 20 species have been recorded, 4 of these dominate in the area under study. Euphttsia krohnii, Nematoscelis megalops and Thysanoessa gregaria are atlantic temperate species, whereas Nyctiphanes capensis inhabits neritic areas around the edge of the Banc d' Arguin, together with Euphausia hanseni from the Southern Atlantic. The population density of the euphausiids in the upwelling area is very high. The vertical distribution of the dominant species E. krohnii and N. megalops reveal significant differences. E. krohnii occurs down to a depth of 200 m, whereas N. megalops lives between 100 and 300 m. The shelf and the edge of the shelf (down to 2000 m) are populated by different species. On the shelf, adult and juvenile N. capensis predominate, but great numbers of juvenile N. megalops have also been found. Along the edge of the shelf E. krohnii, N. megalops and T. gregaria are most abundant. E. hanseni was represented by juveniles, both on the shelf and along its edge. Comparing the species composition of the area under study with that of other regions of the North Atlantic, the dominant species exhibit certain similarities with the species present near Cap Verde and Canary Island, but none similarities could be established with the Great Meteor Seamount. The reasons for this situation are discussed.

Description: On the cruises 3 and 15 of R. V. "Meteor" a number of benthic abyssal gastropods has been collected. Two of the species found in these samples belong to the subgenus Theta CLARKE, 1959 of the genus Pleurotomella. One of the species is Pleurotomella (Theta) lyronuclea CLARKE, 1959, hitherto only known by one single specimen from off Bermuda; CLARKE's description is completed, based on the additional specimens now available. The other one is a new species named Pl. (Theta) bathyiberica, which is described and photographed.

Description: Twentyone species of euthecosomes were present in the IIOE collections and most of them were very abundant in the upwelling and divergence areas such as the Somali coast, the South Arabian coast, the areas around India and Ceylon and off Java. The seasonal changes in the above areas were prominent. A gradual reduction in the number of species was found from South to North with the maximum (20) in the West Australian sea and minimum (12) in the northern Arabian Sea. L. lesueuri is named as the indicator of the subtropical watermass, C. globu­losa, the equatorial watermass and C. uncinata, the watermass around Andaman Islands. Ten patterns of distribution were traced with the biohydrographic boundaries at Bab el Mandeb, around Gulf of Oman, off central west coast of India, around 10° N, 10° S and 40° S. A distinct hydrological barrier found around 10° N has not only helped to explain the unique pattern of distribution in the north Indian Ocean but also supports the theory that the faunistic barrier exists in the open ocean.

Description: In this account 101 species of fishes derived from the bottom hauls on the shelves of the coast of Portugal and of Morocco, the Great Meteor Seamount, the Josephine Seamount and the Gettysburg Bank have been identified and arranged in systematic order. For all a few of the most relevant synonyms are mentioned, the material is enumerated and measurements are given under the stations it has been taken at. Only some of the most common and well-known species were not described, for others a short to detailed description is given, and some taxonomical and morphological points are discussed. The range of distribution of each species has been treated as comprehensively as possible. The stations, their dates, exact positions, depths and gear are given in a list.

Description: The cruises "Valdivia" 10 and "Meteor" 39/1975 had geological and geophysical investigations as focal points. They covered the northwest African continental margin between Morocco (33.5° N) and the southernmost Senegal (12° N) with the purpose: 1) to fill gaps from previous "Meteor" cruises, 2) to contribute to post-site surveys for DSDP Leg 41 (sites 367-370) and 3) to provide pre-site surveys for DSDP Legs 47 and 51 and IPOD crustal site 7 area around 21° N/32° W. The equipment used was similar to "Meteor" cruise 25/1971 with the main exceptions being the new multi-channel, digital seismic system of the BGR (Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover) (Meteor 39-1), refraction seismic buoys, the Kiel multisonde for measuring physical oceanographic parameters (Meteor 39-2) and continuous television observations from a slowly moving ship (Valdivia 10-3). The activities are summarized in Table 1. The scien1ific goals, cruise log, equipment used, participants, profiles and station lists as well as some preliminary results form the contents of the report.

Description: Sedimentological and biostratigraphic investigations of 15 cores (total length: 88 m) from the vicinity of Great Meteor Seamount (about 30° N, 28° W) showed that the calcareous oozes are asymmetricaly distributed around the seamount and vertically differentiated into two intervals. East and west of the seamount, the upper "A"-interval is characterized by yellowish-brown sediment colors and bioturbation; ash layers and diatoms are restricted to the eastern cores. On both seamount flanks, the sediments of the lower "B"-interval are white and very rich in CaC03 with a major fine silt (2-16 μ) mode (mainly coccoliths). Lamination, manganese micronodules, Tertiary foraminifera and discoasters, and small limestone and basalt fragments are typical of the "B"-interval of the eastern cores only. The sediments contain abundant displaced miaterial which was reworked from the upper parts of the seamount. The sedimentation around the seamount is strongly influenced by the kind of displaced material and the intensity of its differentiated dispersal: the sedimentation rates are generally higher on the east than on the west flank (e.g. in "B" : 0.9 cm/1000 y in the W; 3.1 cm/1000 y in the E), and lower for the "A" than for the "B"-interval. The lamination is explained by the combination of increased sedimentation rates with a strong input of material poor in organic carbon producing a hostile environment for benthic life. The CaC03 content of the cores is highly influenced by the proportion of displaced biogenous carbonate material (mainly coccoliths). The genuine in-situ conditions of the dissolution fades are only reflected by the minimum CaCOs values of the cores (Fig. 23; CCD = about 5,500 m; first bend in dissolution curve = 4,000 m; ACD = about 3,400 m). The preservation of the total foraminiferal association depends on the proportion of in-situ versus displaced specimens. In greater water depths (stronger dissolution), for example, the preservation can be improved by the admixture of relatively well preserved displaced foraminifera. Carbonate cementation and the formation of manganese micronodules are restricted to microenvironments with locally increased organic carbon contents (e.g. pellets; foraminifera). The ash layers consist of redeposited, silicic volcanic glass of trachytic composition and Mio-Pliocene age; possibly, they can be derived from the upper part of the seamount. Siliceous organisms, especially diatoms, are frequent close to the ash layers and probably also redeposited. Their preservation was favoured by the increase of the Si02 content in the pore water caused by the silicic volcanic glass. The cores were biostratigraphically subdivided with the aid of planktonic foraminifera and partly also coccoliths. In most cases, the biostratigraphically determined cold- and warm sections could be correlated from core to core (Fig. 21). Almost all cores do not penetrate the Late Pleistocene. All Tertiary fossils are reworked. In general, the warm/cold boundary W2/C2 corresponds with the lithostratigraphic A/B boundary. Benthonic foraminifera indicate the original site of deposition of the displaced material (summit plateau or flanks of the seamount). The asymmetric distribtttion of the sediments around the seamount east and west of the NE-directed antarctic bottom current (AABW) is explained by the distortion of the streamlines by the Coriolis force; by this process the current velocity is increased west of the seamount and decreased east of it (Fig. 25). The different proportion of displaced material within the "A" and "B" interval is explained by changes of the intensity of the oceanic circulation. At the time of "B" the flow of the AABW around the seamount was stronger than during "A"; this can be inferred from the presence of characteristic benthonic foraminifera. The increased oceanic circulation implies an enhanced differentiation of the current velocities, and by that, also of the sedimentation rates, and intensifies the winnowing processes on the seamount plateau. The winnowed sediment material was transported downslope by turbid layers into the deep-sea, incorporated into the current system of the AABW, and asymmetrically deposited around the seamount.

Description: By critical examination of the stratigraphical methods and interpretations applied to Eastern Mediterranean Quaternary sediments, "endemic" (Mediterranean) and "foreign" (non-Mediterranean) data are separated. Basing on the "endemic" data, cores of various authors are correlated by lithology as well as by Foraminifera frequency curves. Using "cycles" (containing a basal warm and the following cold period) a chronological interpretation of Foraminifera frequency curves, similar to that of PARKER (1958) is given. lt is applicable to curves of all authors.

Description: In the sediments of the NW African continental margin the mainly biogenic carbonate constituents become increasingly diluted with terrigenous material as one approaches the coast, as indicated by the carbonate-C02 content, the Al20a/Si02-ratios, and the presence of ammonia fixed to alumino-silicates, predominantly to illites. In the northern area of investigation - off Cape Blanc and Cape Bojador - the terrigenous constituents are mainly quartz from the Sahara Desert, whereas in the south - off Senegal - more alumino-silicates as clay minerals are admixed with the carbonate constituents. The organic carbon content of the continental slope sediments off Senegal is higher than in samples of the continental rise or of the shelf, indicating optimal conditions for the preservation of organic matter as a result of high production and relatively rapid sedimentation. The zone of manganese-oxide enrichment follows the redox potential of + 330 m V from the surface (0-5 cm) into the sediments (20-30 cm deep) at 2000-3000 m and 3700 m of water depths, respectively. At shallower water depths, low redox potentials preclude deposition of manganese oxides and cause their mobilization from the sediments. About 1/3 of the total sedimentary Zn and 1/4 of the Cu is associated with the carbonate mineral fraction, probably in calcium phosphate overgrowths as a result of the mineralization of phosphorus-containing organic matter. Besides the precipitation of calcium phosphate, the mineralization of organic matter mediated by bacterial sulfate reduction also results in calcium carbonate precipitation and the exchange of ammonia for potassium on illites. Because of these simultaneous reactions, the depth distribution of all mineralization constituents in the interstitial water can be determined using the actual molar carbon-to-nitrogen-to-phosphorus ratios of the sedimentary organic matter. The amount of sulfide sulfur in this process indicates the predominance of bacterial sulfate reduction in the sediments off NW Africa. This process also preferentially decomposes nitrogen- and phosphorus-containing organic compounds so organic matter deficient in these elements is characteristic for the rapidly accumulating sediments. During the last glacial stage there were more biogenic carbonates and organic matter accumulating in the sedimcnts than today, indicating there was increased production of organic carbon compounds and more favorable conditions for their preservation. During the last interglacial times conditions were similar to those of today. This differentiation with time has also been observed in sediments from thc Argentine Basin and from the slope off South India indicating perhaps world-wide environmental changes throughout Late Quaternary times.