Pleistocene deltaic progradation of continental terrace, Costa de Nayarit, Mexico : Curray J. R. and D. G. Moore, 1964. In: Marine geology of the Gulf of California, a symposium. Amer. Ass. Petrol. Geol., Memoir, (Edited by van Andel T., and George G. Shor Jr.), 3: 193–215

576 Oceanographic Abstracts COPELAND B. J. and W. R. DUFFER, 1964. Use of a clear plastic dome to measure gaseous diffusion rates in natural waters. Limnol. Oceanogr., 9 (4): 494-499. Experiments were conducted in both standing and moving water communities to evaluate the use of a plastic dome for correcting diurnal oxygen curves for diffusion of oxygen between the air- water interface. Diurnal oxygen curves in systems where diffusion of oxygen through the air-water boundary occurs were corrected by means of data from the plastic dome experiments to obtain curves in agreement with those from closed systems with no diffusion. The upstream-downstream diurnal oxygen curve method for running water ecosystems was modified to yield diurnal rate-of- change curves like those in still water. COQUEMA C., R. CO~LOMa et J. Ros, 1963. l~tude g6ochemique de deux carottes de s6diment du bassin occidental de la M6diterran6e. Rapp. Prec. Verb. Rdunions, Comm. Int., Exp. Sci., Met Mdd., Monaco, 17 (3): 1009-1019. Les s6diments 6tudi6s sent compos6s d'une partie biog6ne et d'une partie minerale. La partie biog6ne est compos6¢ presque exclusivement du carbonate de calcium provenant des tests de foraminif6res et des pt6ropodes. La pattie min6rale, pour les 616ments principaux, a une composition chimique analogue a celles du Pacifique et de l'Atlantique et ne pr6sente pas de calcaire d6tritique en quantit6 appr6ciable. La faible teneur en mangan6se des s6diments analys6s peut 6tre due ~t la plus grande vitesse de s6dimentation en M6diterran6¢ que dans les oc6ans. Les pies observ6s dans la distribution du mangan6se et du phosphore peuvent 6tre dus ~ la migration de ces ions dans la colonne s6dimentaire. CORCORAN E. F. and J. E. ALEXANDER, 1963. Nutrient, chlorophyll and primary production studies in the Florida current. Bull. Mar. Sci., Gulf Caribb., 13 (4): 527-541. Inorganic and total phosphates, Kjeldahl nitrogen, ammonia, nitrite and nitrate nitrogen, iron and silicate have been measured at a station in the Florida current 40 miles east of Miami, Florida in 738 m of water. This station has been occupied at monthly intervals for 31 months. Standing crop and primary production have been measured by chlorophyll and 14C methods for 9 months. Nutrient concentrations were low in the upper waters. Phosphates and nitrates ranged from 0.0 to 0"3/~g-at P/L and from 0"0 to 10/~g-at N/L. Ammonia and Kjeldahl nitrogen ranged 0.3 to 0.4/~g-at N/L. Silicate was generally not detectable and iron was principall~ present in particulate state with concentration ranging up to 6/~g/L. Standing crop ranged from 0"05-0"Stag, chlorophyll a/m a. Net production ranged from 0"2-0.5 mg C/ma/day. Factors controlling production in this region and which differentiate it from those of higher latitudes are (l) shallow winter mixed layer, (2) low concentration of nutrients, and (3) a rapid re-cycling of nutrients. CRISAH P. Les Cop6podes pelagiques du detroit de Messine Pleuromamma abdominalis [.Lubbock) et Pleuromamma gracilis (Claus) (Copepoda, Calanoida). Morphologie, d6veloppement et frequenee. Rapp. Proc. Verb., Comm. Int. Exp. Sci., Mer Mdd., Monaco, 1963, 17 (2): 555-561. Genus Pleuromamma is represented in the straits of Messina by both the species Pleuromamma abdominalis and Pleuromamma gracilis. Copepodite stages and the frequency of males, females and copepodite stages were studied. CURRAV J. R. and D. G. MOORE, 1964. Pleistocene deltaic progradation of continental terrace, Costa de Nayaxit, Mexico. In: Marine geology of the Gulf of California, a symposium. Amer. Ass. Petrol Geol., Memoir, (Edited by VAN ANDEL T., and GEORGE G. SHOR JR.), 3:193-215. The sedimentary structure of the continental terrace of the Costa de Nayarit, on the west coast of mainland Mexico, has been investigated geophysically by means of continuous acoustic reflection profiling. Facies interpretations are made from these records and profiles on the basis of shape, attitude, nature of internal reflecting horizons, and relationship to adjacent facies. The framework of this continental terrace is composed of a sequence of wedges of deltaic sediments, interspersed with strata of other paralic and open-shelf facies, which grade seaward into continental-slope facies. The deltaic platforms are correlated and matched with flanking erosional shorelines to obtain a chronology of deltaic progradation to the edge of the terrace. Low positions of sea level below -- 65 fins are postulated for early Wisconsin time. Younger sequences, believed to be of late Wisconsin age, were formed during fluctuations of sea level between - - 35 and -- 68 fins. The youngest low stand of sea level at -- 68 fins is dated 17,600 yr B.P. The northern part of this terrace is nondeltaic and consists of a thick section of open-shelf sediments grading seaward over a deep, rounded shelf-break into a thick section of slope sediments. Faulting in the reitection records shows that this thick section was deposited on a subsiding platform. It is concluded that shelf and slope deposits are volumetrically very important in regions like the Costa de Nayarit. The break in slope at the edge of the southern and central Costa de Nayarit shelf is very complex in origin, but is primarily controlled by Pleistocene deltas. The edge of the northern subsiding portion of the shelf is also depositional in origin, but is only indirectly controlled by lowered sea Oceanographic Abstracts 577 level. Long-term balance between deposition and removal of sediment, controlled by wave action well below surf-base (about 5 fins), and by surf erosion during past transgressions and regressions, must form terrace structures of this northern type. These may have been processes of geological importance in pre-Quaternary time. Thus the explanation for the world-wide origin of the sbelf- break as caused primarily by surf erosion during lowered sea level appears oversimplified. Cvnc V., 1963. Distribution des bact6ries et de la biomasse bact6rienne dans rAdriatique. m6ridionale. (In Jugoslavian; French resume). Acta Adriatica, 10 (7): 15 pp. Dans ce travail on presente la distribution des bact6ries h6t6rotropbes. I.¢ nombre de bact6ries h6t6rotrophes/t un cm s va de I ~ 7.200 de cellules bact6riennes et le d6veloppement de la population bact6rienne atteint hahituellement son maximum dans la coucbe de 0 /t 100 m. Le maximum estival et hivernal, ainsi que le minimum printanier et automnal sont clairement exprim6s. La population bact6rienne des bact6ries h6t6rotropbes dans rAdriatique m6ridionale est con- sid6rablement plus pauvre que celle de l'Adriatique moyenne. La distribution de la biomasse bact6rienne dans les eaux de l'Adriatique m6ridionale pr6sentait commesa caract6ristique quelques minima (0-100, 3(D--400 et sur le fond) dont celui constat6 pendant la croisi6re de juin etait le plus fortement exprim6. La biomasse moyenne allait de 13.60/t 17-68 et la biomasse la plus riche trouv6¢ au cours de ces quatre croisi6res rut celle constat6o en juin 1957. On a constat6 un¢ oscillation saisonni6re de la biomass¢ bact6rienne clairement exprim6e, pr6sentant des valeurs maxima et 6t6 et en hirer et des valeurs minima au printemps et en automne. 11 ¢st int6ressant de remarquer que la biomasse bact6rienne attegnait le maximum de son d6veloppe- ment dans les zones des thermoclines. DAL PONT G. and B. NEWELL, 1963. SuspEnded organic matter in the Tasman Sea. Aust. J. Mar. Freshwat. Res., 14 (2): 155-165. Samples of particulate material were collected down to 4500 m at a station in the Tasman Sea. The material was analysed for its carbon and nitrogen content. Determinations of total organic phosphorus were also made on water samples collected at the same depths. Some 400 g of carbon were found under 1 m ~ of sea surface, and the vertical distribution of particulate carbon, nitrogen, and organic phosphorus was closely related to the hydrological structure. DARBYSHtgE J., 1963. A study of microseisms in South Africa. Geophys. J. Roy. Astron. See., Lend., 8 (2): 165-175. Microseisms have been recorded at Hermanus near Cape Town since October 1961, using an N.I.O. two-component~ horizontal seismograph. Wave records have also been taken by means of a ship- borne wave recorder aboard R.S. Africana H. The spectra of waves and microseisms due to a storm in April 1962 arc conipared and there is a two to one frequency relationship as would be expected from the wave interference theory of microseism generation. Estimates were made of the direction of approach of the microseisms, assuming various models and allowing for the effect of refraction. The evidence on the whole suggests that the microseisms consist of a mixture of Rayleigh and Love waves coming from the same range of directions. DAgBYSmgE J., 1964. A hydrological investigation of the Agulhas Current. Deep-Sea Res., 11 (5): 781-815. The results of six cruises of S.A.S. Natal, two during the I.G.Y. and four during 1962-63 in the Agnlhas Current area are examined. These are supplemented by the results of one of the Africans H cruises to Marion and Crozet Is. The results show a marked seasonal variation in the Agulhas Current, which is strongest in April and weakest in October. A strong return flow in 25°-30°E, 35°-40°S is observed in all cases. Examination of the data taken simultaneously by Natal and Afrtcana H shows that the return flow merges with the west wind drift and also indicates the areas of the Agulhas and Sub-tropical convergences. Numerous large eddies are seen to be contained in the current system, particularly in the area east of Durban. The current system appears to be modified only very little by the local winds and is affected mainly by the variations in the South Equatorial Current and the west wind drift. Oxygen and phosphate determinations were obtained during the cruises and their distribution is discussed and compared with that of the water temperature. DAY J. A., 1964. Production of droplets and salt nuclei by bursting of air-bubble films. Quart. J. Roy. Met. See., 90 (383): 72-78. Air bubbles which burst at the surface of a liquid give rise to an array of small bubble-film droplets and subsequent jet drops. Both are of meteorological significance in that they are the major means by which salt particles arc injected into the atmosphere. Counts are made of the numbers of film droplets produced by bubbles of known diameter as they burst in the highly supersaturated environment of a water diffusion cloud chamber. It is found that, (1) the number of film droplets produced is dependent on bubble size, ranging from none for 0"1 mm diameter bubbles to 300-400 for 4mm diameter bubbles in salt water; (2) the mean number of film droplets is proportional to the one-half power of the bubble cap area; (3) larger numbers of film droplets are produced when bubbles burst in three per cent NaCI solution