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A reconnaisance survey of the environment of Recent carbonate sedimentation along the Trucial coast, Persian Gulf
T044
Oceanographic Abstracts
EVANS G., D. J. J. KINSMAN and. D, J, SHEARMArq, 1964. A re,~onnaisance survey of the environmerit of Recent carbonate sedimentation along the Trucial coast, Persian Gulf. In : Developments in Sedimentology, L.M.J.U. Van Straaten, Editor, Elsevier, I : 129-135. The physiographic setting of an area of Recent carbonate sedimentation along the Trucial Coast, Persian Gulf is described. Previous work on the sediments and waters of the Persian Gulf is briefly reviewed. The paper forms the background for the description of the sediments of part of the area discussed (see KINSMAN, 1963)~ EvZTr W~H,JAM R. and SUSAN E. DAVIDSON, 1964. Dinoflagellate studies. I. Dinoflagcltalc cysts and thecae. Stanfi~rd Unit,. Pubis. Geol, Sei., 10 (1): 1-12. Studies of the thecae and resting cysts of four modern dinoflagellates- Gonyaulax polyedra Stein, G. digitale (Pouchet) Kofoid, Protocertatium retieulatum Ctapar~de and Lachmann, and Peridinium leonis Pavillard -- support earlier hypotheses, based on morphological studies of fossils, that hystrichospheres are dinoflagellate cysts and that fossil dinoflagellates are fossil cysts rather than fossil thecae. Hystrichosphaera is identified as one of the types of cyst of Gonyaulax. Problems and opportunities in the systematics and nomenclature of dinoflagellates are pointed out. EWING MAURICE and .IOHN EWlNG, 1964. Distribution of oceanic sediments. In: Stttdic.~ on Oceanography dedicated to Profi'ssor Hidaka in Commemoration of his Sixtieth Birthday, 525-537 Sediment thickness and stratification show a surprising degree of variation in the ocean sediments. Seismic profiler data obtained on Columbia University expeditions are described for crossings of all the world's oceans. The paucity of sediments is a significant observation. The thickest sedimenls are near continental masses, accessible to terrigenous sediments. Most sediments in the Atlantic basins were deposited in a manner that produced horizontal interfaces. An extensive, smooth s-ub. bottom horizon was observed in the Atlantic. Large areas of the Pacific and Indian Ocean basins have an exceedingly thin sediment cover. Except for gentle crustal warping, there is little evidence of deformation after or during sedimentation. FLEMINGER ABRAHAMand ROB[!RI I. CI,UrTt-R, 1965. Avoidance of towed nets by zooplankto~ ~, Limnol. Oceanogr., I 0 (I) : 96 104. Experiments were conducted to determine the effect of behaviour on the accuracy of sampling populations composed of several species of marine copepods and mysids held in a large, enclosed seawater pool. Plankton nets having mouth areas of 1,600, 800 and 400 cmz were towed in replicate sets during midday and midnight under three light conditions in plankton populations of different densities. Statistical treatment of the results showed that smaller nets were more effectively avoided and that the degree of avoidance varied among species. Estimates of the peripheral escape zone werc obtained. More mysids, but not more copepods, were caught in darkness than in light, and avoidance tended to be less in denser populations. Time of day had no effect on avoidance behaviour. Escape mechanisms and the possible effect of population density are discussed. FLEMMING IN. C., 1964. Tank experiments on the sorting of beach material during cusp formatioz~ J, sedim. Petrol., 34 (1): 112-122. Nine experiments with 2-inch waves breaking for as much as 48 hours on a beach of pebbles and sand produced cusps in 8 cases. Seven runs produced cusps which changed continuously and one run became stable after two hours and unchanged for 24 hours. The stable beach was analysed for size and shape sorting in area and depth. Large particles were concentrated on the surface at the uppc~ and lower limits of the beach, and near the waterline the modal size increased verti:al!y downwards. There was no significant difference in the size sorting between cusps and bays. The most spherical particles concentrated at the foot of the beach, the plate-like ones at the back of the bays, and the cusp points were a mixture of plates and tetrahedra. This is explained in terms of transport up the beach by suspension, and down-beach by dragging and rolling. Stability was increased by the high permeability of the mixture on the cusp points. FOLSOM T. R., C. FELDMAN and T. C. RAINS, 1964. Variation of cesium in the ocean. Sciem~ ,, 144 (2618): 538-539. Samples of sea water from several oceans and several depths were analyzed for natural cesium b~ flame photometry with precision of about 3'5 ~ . The average of 16 assays of surface water from four oceans was 0.37 microgram per liter, somewhat less than the average previously reported. The average cesium concentration i n samples taken between 500 and 1500 m was about 14 % higher than the surface average, suggesting that cesium may be t r a n s p o r t e d downward by particulate material. Natural cesium is now somewhat easier to study in the ocean than radiocesium from fallout is, and information on one complements the other. FUNNELL B. M., 1964. Studies in North Atlantic geology and palaeontology: 1. Upper Cretaceous: Geol. Mag., 101 (5): 421-434. An Upper Maastrichtian assemblage of planktonic foraminifera is recorded from chalk dredged from Galicia Bank, a non-magnetic seamount off the west coast of Spain. The occurrence and dis-
Oceanographic Abstracts
EVANS G., D. J. J. KINSMAN and. D, J, SHEARMArq, 1964. A re,~onnaisance survey of the environmerit of Recent carbonate sedimentation along the Trucial coast, Persian Gulf. In : Developments in Sedimentology, L.M.J.U. Van Straaten, Editor, Elsevier, I : 129-135. The physiographic setting of an area of Recent carbonate sedimentation along the Trucial Coast, Persian Gulf is described. Previous work on the sediments and waters of the Persian Gulf is briefly reviewed. The paper forms the background for the description of the sediments of part of the area discussed (see KINSMAN, 1963)~ EvZTr W~H,JAM R. and SUSAN E. DAVIDSON, 1964. Dinoflagellate studies. I. Dinoflagcltalc cysts and thecae. Stanfi~rd Unit,. Pubis. Geol, Sei., 10 (1): 1-12. Studies of the thecae and resting cysts of four modern dinoflagellates- Gonyaulax polyedra Stein, G. digitale (Pouchet) Kofoid, Protocertatium retieulatum Ctapar~de and Lachmann, and Peridinium leonis Pavillard -- support earlier hypotheses, based on morphological studies of fossils, that hystrichospheres are dinoflagellate cysts and that fossil dinoflagellates are fossil cysts rather than fossil thecae. Hystrichosphaera is identified as one of the types of cyst of Gonyaulax. Problems and opportunities in the systematics and nomenclature of dinoflagellates are pointed out. EWING MAURICE and .IOHN EWlNG, 1964. Distribution of oceanic sediments. In: Stttdic.~ on Oceanography dedicated to Profi'ssor Hidaka in Commemoration of his Sixtieth Birthday, 525-537 Sediment thickness and stratification show a surprising degree of variation in the ocean sediments. Seismic profiler data obtained on Columbia University expeditions are described for crossings of all the world's oceans. The paucity of sediments is a significant observation. The thickest sedimenls are near continental masses, accessible to terrigenous sediments. Most sediments in the Atlantic basins were deposited in a manner that produced horizontal interfaces. An extensive, smooth s-ub. bottom horizon was observed in the Atlantic. Large areas of the Pacific and Indian Ocean basins have an exceedingly thin sediment cover. Except for gentle crustal warping, there is little evidence of deformation after or during sedimentation. FLEMINGER ABRAHAMand ROB[!RI I. CI,UrTt-R, 1965. Avoidance of towed nets by zooplankto~ ~, Limnol. Oceanogr., I 0 (I) : 96 104. Experiments were conducted to determine the effect of behaviour on the accuracy of sampling populations composed of several species of marine copepods and mysids held in a large, enclosed seawater pool. Plankton nets having mouth areas of 1,600, 800 and 400 cmz were towed in replicate sets during midday and midnight under three light conditions in plankton populations of different densities. Statistical treatment of the results showed that smaller nets were more effectively avoided and that the degree of avoidance varied among species. Estimates of the peripheral escape zone werc obtained. More mysids, but not more copepods, were caught in darkness than in light, and avoidance tended to be less in denser populations. Time of day had no effect on avoidance behaviour. Escape mechanisms and the possible effect of population density are discussed. FLEMMING IN. C., 1964. Tank experiments on the sorting of beach material during cusp formatioz~ J, sedim. Petrol., 34 (1): 112-122. Nine experiments with 2-inch waves breaking for as much as 48 hours on a beach of pebbles and sand produced cusps in 8 cases. Seven runs produced cusps which changed continuously and one run became stable after two hours and unchanged for 24 hours. The stable beach was analysed for size and shape sorting in area and depth. Large particles were concentrated on the surface at the uppc~ and lower limits of the beach, and near the waterline the modal size increased verti:al!y downwards. There was no significant difference in the size sorting between cusps and bays. The most spherical particles concentrated at the foot of the beach, the plate-like ones at the back of the bays, and the cusp points were a mixture of plates and tetrahedra. This is explained in terms of transport up the beach by suspension, and down-beach by dragging and rolling. Stability was increased by the high permeability of the mixture on the cusp points. FOLSOM T. R., C. FELDMAN and T. C. RAINS, 1964. Variation of cesium in the ocean. Sciem~ ,, 144 (2618): 538-539. Samples of sea water from several oceans and several depths were analyzed for natural cesium b~ flame photometry with precision of about 3'5 ~ . The average of 16 assays of surface water from four oceans was 0.37 microgram per liter, somewhat less than the average previously reported. The average cesium concentration i n samples taken between 500 and 1500 m was about 14 % higher than the surface average, suggesting that cesium may be t r a n s p o r t e d downward by particulate material. Natural cesium is now somewhat easier to study in the ocean than radiocesium from fallout is, and information on one complements the other. FUNNELL B. M., 1964. Studies in North Atlantic geology and palaeontology: 1. Upper Cretaceous: Geol. Mag., 101 (5): 421-434. An Upper Maastrichtian assemblage of planktonic foraminifera is recorded from chalk dredged from Galicia Bank, a non-magnetic seamount off the west coast of Spain. The occurrence and dis-