GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Document type
Keywords
Language
  • 1
    Keywords: Aufsatzsammlung ; Kontinentalabhang ; Schwemmfächer ; Suspensionsströmung ; Unterwasserboden ; Suspensionsströmung
    Type of Medium: Book
    Pages: XIV, 351 S , Ill., graph. Darst., Kt , 1 Kt , 29 cm
    ISBN: 0387961429 , 3540961429
    Series Statement: Frontiers in sedimentary geology
    DDC: 552'.5
    RVK:
    RVK:
    Language: English
    Note: Teilw. aus: Geo-marine letters. 3,2-4. 1984. - Literaturangaben
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    facet.materialart.
    Unknown
    PANGAEA
    In:  Supplement to: Cyamex Scientific Team; Francheteau, Jean; Needham, H D; Choukroune, P; Juteau, Thierry; Séguret, Marie J M; Ballard, R D; Fox, P J; Normark, William R; Carranza, A; Cordoba, D; Guerrero, Gerardo; Rangin, Claude (1981): First manned submersible dives on the East Pacific Rise at 21�N (project RITA): General results. Marine Geophysical Research, 4(4), 345-379, https://doi.org/10.1007/BF00286034
    Publication Date: 2023-08-28
    Description: A submersible study has been conducted in February - March 1978 at the axis of the East Pacific Rise near 21°N. The expedition CYAMEX, the first submersible program to be conducted on the East Pacific Rise, is part of the French-American-Mexican project RITA (Rivera - Tamayo), a 3-year study devoted to detailed geological and geophysical investigations of the East Pacific Rise Crest. On the basis of the 15 dives made by CYANA in the axial area of the Rise, a morphological and tectonic zonation can be established for this moderately-fast spreading center. A narrow, 0.6 to 1.2 km wide zone of extrusion (zone 1), dominated by young lava flows, is flanked by a highly fissured and faulted zone of extension (zone 2) with a width of 1 to 2 km. Further out, zone 3 is dominated by outward tilted blocks bounded by inward-facing fault scarps. Active or recent faults extend up to 12 km from the axis of extrusion of the East Pacific Rise. This represents the first determination from direct field evidence of the width of active tectonism associated with an accreting plate boundary. Massive sulfide deposits, made principally of zinc, copper and iron, were found close to the axis of the Rise. Other signs of the intense hydrothermal activity included the discovery of benthic fauna of giant size similar to that found at the axis of the Galapagos Rift. We emphasize the cyclic character of the volcanicity. The main characteristics of the geology of this segment of the East Pacific Rise can be explained by the thermal structure at depth below this moderately-fast spreading center. The geological observations are compatible with the existence of a shallow magma reservoir centered at the axis of the Rise with a half-width of the order of 10 km.
    Keywords: CY78-16DF; CY78-17V; CY78-18V; CYAMEX; Cyana (Submersible); Deposit type; DEPTH, sediment/rock; Description; East Pacific Rise; Event label; Identification; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; OBSE; Observation; Position; Quantity of deposit; Sediment sample; Sediment type; SES; Substrate type; Visual description
    Type: Dataset
    Format: text/tab-separated-values, 21 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    facet.materialart.
    Unknown
    PANGAEA
    In:  Supplement to: Juteau, Thierry; Eissen, Jean-Philippe; Francheteau, Jean; Needham, David; Choukroune, P; Rangin, Claude; Séguret, Marie J M; Ballard, R D; Fox, P J; Normark, William R; Carranza, A; Cordoba, D; Guerrero, J (1980): Homogeneous basalts from the East Pacific Rise at 21° N: seady state magma reservoirs at moderately fast spreading centers. Oceanologica Acta, 3(4), 487-503, https://archimer.ifremer.fr/doc/00323/43430/
    Publication Date: 2023-08-28
    Description: Forty basaltic rocks collected by submersible during the Cyamex expedition (1978) on the East PacifIc Rise at 21°N, a moderately fast spreading segment (6 cm/year opening rate) of the mid-ocean ridge, consist of angular pillow fragments and glass buds, sheet-flow slabs and samples of columnar pillars standing in collapsed fossillava pools. Most of the rocks are from the crestal are a of the Rise. The collection shows a striking petrographic homogeneity wh en compared with the range of basalts found on other segments of midocean ridges: olivine-phyric, or highly plagioclase-phyric rocks, so common in the slowspreading Famous are a in the Atlantic, are absent. All samples are typical lowpotassium oceanic tholeiites with a limited fractionation trend. Pillow-lavas, thin and thick sheet-flows cannot be distinguished by their major element compositions, as in the Galapagos rift which has the same spreading rate as the EPR at 21°N. Further, ferrobasalts have been described from the Galapagos rift, but do not appear in the Cyamex rocks. In the Cyamex area, olivine and plagioclase are the main silicate phases, and clinopyroxene is absent. In the pillows and sheet-flow samples, four generations of olivine and plagioclase crystals are distinguished. Samples from the fossillava pools are aphyric. The corresponding magma batches are presumed to have migrated rapidly through the magma chamber, and to have been extruded in large volumes, possibly during episodes ofhigh instantaneous opening rate. Fe-Ni and Fe-Cu-rich sulphide phases are common in an lava types as massive globules scatterred through the glass, or as microglobules decorating the walls of empty vesicles. Palagonite and Fe-Mn oxide thicknesses across the strike of the Rise indicate relative ages compatible with successive extrusions at the Rise axis.
    Keywords: CY-78-07-12D; CY-78-10-17D; CY-78-10-18D; CY-78-11-26D; CY-78-12-35D; CY-78-13-42D; CY-78-13-43D; CY-78-13-44D; CY-78-15-55D; CY-78-15-56D; CY-78-16-57D; CY-78-16-58D; CY-78-17-60D; CY-78-17-61D; CY-78-18-63D; CY-78-18-65D; CY-78-18-66D; CY-78-19-69D; CY-78-20-76D; CYAMEX; Cyana (Submersible); Deposit type; DEPTH, sediment/rock; Description; East Pacific Rise; Elevation of event; Event label; Identification; Latitude of event; Longitude of event; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; Percentage; Position; ROBA; Robotic arm; Sediment type; Substrate type; Visual description
    Type: Dataset
    Format: text/tab-separated-values, 108 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    facet.materialart.
    Unknown
    PANGAEA
    In:  Supplement to: Stow, Dorrik A V; Cremer, Michel; Droz, Laurence; Meyer, Audrey W; Normark, William R; O'Connell, Suzanne B; Pickering, Kevin T; Stelting, Charles E; Angell, S A; Chaplin, C (1986): Facies, composition, and texture of Mississippi Fan sediments, Deep Sea Drilling Project Leg 96, Gulf of Mexico. In: Bouma, AH; Coleman, JM; Meyer, AW; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office), 96, 475-487, https://doi.org/10.2973/dsdp.proc.96.121.1986
    Publication Date: 2024-06-25
    Description: Eight lithologic facies recognized in the Mississippi Fan sediments drilled during DSDP Leg 96 are defined on the basis of lithology, sedimentary structures, composition, and texture. Of these, the calcareous biogenic sediments are of minor importance, volumetrically, as compared with the dominant resedimented terrigenous facies. Clay, mud, and silt are the most abundant sediments at all the sites drilled, with some sand and gravel in the midfan channel fill and an abundance of sand on the lower fan. Facies distribution and vertical sequences reflect the importance of sediment type and supply in controlling fan development. Sea-level changes and diapiric activity have also played an important role. Clay and sand fraction mineralogy closely mirror the dominant sediment source, namely, the Mississippi River system and adjacent continental shelf. Local and regional variation in composition on the fan mostly reflects facies differences.
    Keywords: 96-614; 96-614A; 96-615; 96-616; 96-617; 96-620; 96-621; 96-622; 96-623; Deep Sea Drilling Project; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Elevation of event; Event label; Facies name/code; Glomar Challenger; Grain size, sieving; Grain size, sieving/settling tube; Gulf of Mexico/FAN; Latitude of event; Leg96; Longitude of event; Sample code/label; Sand; Silt; Size fraction 〈 0.002 mm, clay
    Type: Dataset
    Format: text/tab-separated-values, 480 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    AAPG
    In:  AAPG Bulletin, 85 (8). pp. 1407-1438.
    Publication Date: 2020-04-22
    Description: Most submarine fans are supplied with both sand and mud, but these become segregated during transport, typically with the sand becoming concentrated in channels and channel-termination lobes. New data from high-resolution seismic reflection surveys and Deep Sea Drilling Project (DSDP)/Ocean Drilling Program (ODP) wells from a variety of fans allow a synthesis of the architecture of those submarine fans that have important sand deposits. By analyzing architectural elements, we can better understand issues important for petroleum geology, such as the reservoir properties of the sand bodies and their lateral continuity and vertical connectivity. Our analysis of fan architecture is based principally on the Amazon and Hueneme fans, generally perceived to be classic examples of muddy and sandy systems, respectively. We recognize depositional elements, for example, channel deposits, levees, and lobes, from seismic reflection data and document sediment character in different elements from DSDP/ODP drill cores. We show the utility for petroleum geology of evaluating sandy and muddy elements rather than characterizing entire fans as sand rich or mud rich. We suggest that fan classification should include evaluation of source-sediment volumes and grain size, as well as the probable processes of turbidity-current initiation, because these factors control the character of fan elements and their response to changes in sea level, sediment supply, and autocyclic changes in channel pattern. Basin morphology, controlled by tectonics, influences overall geometry, as well as the balance between aggradation and progradation.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Sedimentology 31 (1984), S. 0 
    ISSN: 1365-3091
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: Several Holocene turbidites can be correlated across much of Navy Fan through more than 100 sediment core localities. The uppermost muddy turbidite unit is mapped throughout the northern half of the fan; its volume, grain-size distribution and the maximum height of deposition on the basin slopes are known. These parameters can be related to the precise channel morphology and mesotopography revealed by deep-tow surveys. Thus there is sufficient information to estimate detailed flow characteristics for this turbidity current as it moved from fan valley to distal basin plain.On the upper fan, the gradient and the increasing downstream width of the channel and only limited flow overspill suggest that the flow had a Froude number close to 1.0. The sediment associated with the channel indicates friction velocities of about 0.06 m s−1 and flow velocities of about 0.75 m s−1. Using this flow velocity and channel dimensions, sediment concentration (∼2×10−3) and discharge are estimated, and from a knowledge of the total volume of sediment deposited, the flow duration is estimated to be from 2 to 9 days. It is shown that the estimates of Froude number, drag coefficient, and sediment concentration are not likely to vary by more than a factor of 2.On the mid-fan, the flow was much thicker than the height of the surface relief of the fan and it spread rapidly. The cross-flow slope, determined from the horizontal extent of turbidite sediment, is used to estimate flow velocity, which is confirmed by consideration of both sediment grain size and rate of deposition. This again allows sediment concentration and discharge to be estimated. The requirements of flow continuity, entrainment of water during flow expansion, and observed sediment deposition provide checks on all these estimates, and provide an integrated picture of the evolution of the flow. The flow characteristics of this muddy turbidity current are well constrained compared to those for more sand-rich late Pleistocene and early Holocene turbidity currents on the fan.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Sedimentology 30 (1983), S. 0 
    ISSN: 1365-3091
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The late Pleistocene and Holocene stratigraphy of Navy Fan is mapped in detail from more than 100 cores. Thirteen 14C dates of plant detritus and of organic-rich mud beds show that a marked change in sediment supply from sandy to muddy turbidites occurred between 9000 and 12,000 years ago. They also confirm the correlation of several individual depositional units. The sediment dispersal pattern is primarily controlled by basin configuration and fan morphology, particularly the geometry of distributary channels, which show abrupt 60° bends related to the Pleistocene history of lobe progradation. The Holocene turbidity currents are depositing on, and modifying only slightly, a relict Pleistocene morphology.The uppermost turbidite is a thin sand to mud bed on the upper-fan valley levées and on parts of the mid-fan. Most of its sediment volume is in a mud bed on the lower fan and basin plain downslope from a sharp bend in the mid-fan distributary system. Little sediment occurs farther downstream within this distributary system. It appears that most of the turbidity current overtopped the levée at the channel bend, a process referred to as flow stripping. The muddy upper part of the flow continued straight down to the basin plain. The residual more sandy base of the flow in the distributary channel was not thick enough to maintain itself as gradient decreased and the channel opened out on to the mid-fan lobe.Flow stripping may occur in any turbidity current that is thick relative to channel depth and that flows in a channel with sharp bends. Where thick sandy currents are stripped, levée and mid-fan erosion may occur, but the residual current in the channel will lose much of its power and deposit rapidly. In thick muddy currents, progressive overflow of mud will cause less declaration of the residual channelised current. Thus both size and sand-to-mud ratio of turbidity currents feeding a fan are important factors controlling morphologic features and depositional areas on fans. The size-frequency variation for different types of turbidity currents is estimated from the literature and related to the evolution of fan morphology.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1365-3091
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The deep-tow instrument package of Scripps Institution of Oceanography provides a unique opportunity to delineate small-scale features of a size comparable to those features usually described from ancient deep-sea fan deposits. On Navy Fan, the deep-tow side-scanning sonar readily detected steep channel walls and steps and terraces within channels. The most striking features observed in side-scan are large crescentic depressions commonly occurring in groups. These appear to be large scours or flutes carved by turbidity currents. Four distinct acoustic facies were mapped on the basis of qualitative assessment of reflectivity of 4 kHz reflection profiles. There is a distinct increase in depth of acoustic penetration, number of sub-bottom reflectors, and reflector continuity from the upper fan-valley to the lower fan. These changes are accompanied by a decrease in surface relief.Navy Fan is made up of three active sectors. The active upper fan is dominated by a single channel with prominent levees that decrease in height downstream. The active mid-fan region or suprafan is where sand is deposited. Well defined distributary channels with steps, terraces, and other mesotopography terminate in depositional lobes. Interchannel areas are rough, containing giant scours as well as other relief. The active lower fan accumulates mud and silt and is without resolvable surface morphology.The morphological features seen on Navy Fan other than levees, interchannel areas, and lobes are principally erosional. The distributary channels are up to 0.5 km wide and 5–15 m deep. Such features, because of their large size and low relief, are rarely completely exposed or easily detectable in ancient rock sequences. Some flute-shaped scours are larger than channels in cross section but many are 5-30 m across and 1-2 m deep. If observed in ancient rocks transverse to palaeo-current direction, they would perhaps be indistinguishable from channels. Surface sediment distribution combined with fan morphology can be used to relate modern sediments to facies models for ancient fan sediments. Gravel and sand occur in the upper valley, massive sand beds in the mid-fan distributary channels, classical complete Bouma sequences on depositional lobes, incomplete Bouma sequences (lacking division a) on the lower mid-fan, and Bouma sequence with lenticular shape or other limited extent on mid-fan interchannel areas and on levees.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Sedimentology 23 (1976), S. 0 
    ISSN: 1365-3091
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The discharge of taconite tailings into Lake Superior at Silver Bay, Minnesota, produces turbidity current flow. The silty fine-sand tailings fraction transported to the deepest part of the lake has formed a small fan with valleys similar in gross morphology to a submarine fan. Current meters anchored 5 m above the lake floor over the wall and over the levee of a distributary valley on the fan recorded intermittent turbidity current flows during 30 weeks in 1972–73. At least twenty-five discrete periods of observation of turbidity current flow were obtained; single episodes lasted 4−328+ h. Only flows thick enough to overflow the eastern levee of the valley could be observed, and this accounts for the intermittent nature of our observations, as flow within the valleys is expected to be continuous as long as tailings are discharged. Flow velocities were higher near the valley axis where the flow is thicker. Velocities measured over the valley wall averaged 10.8 cm/s for eleven episodes; velocities measured over the levee, more than 1/2 km from the valley axis, only 3.3 cm/s. The maximum velocity during 1300 h of observation did not exceed 31 cm/s. This agrees reasonably well with velocities calculated from channel properties, as commonly done for turbidity currents on deep-sea fans. Current meters tethered above the bottom meters indicate that lake currents normally parallel the shore throughout the water column. With the onset of a turbidity current, currents higher in the water column remain unchanged but velocities near the bottom go to zero, currents then change azimuth by 90° to parallel the downslope (down-valley) direction of the fan, then increase in velocity. During a turbidity current episode, the direction of bottom flow stays relatively constant (± 20° of the down-valley trend) but the velocity oscillates (commonly with 10 cm/s amplitude), periods being of 1/2 h or less to several hours. Turbidity currents generated on Reserve Mining Company's delta are effective in carrying essentially all tailings discharged into the lake into deeper water, where they are deposited.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Sedimentology 35 (1988), S. 0 
    ISSN: 1365-3091
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The Sur debris slide and associated debris flow cover more than 1000 km2 of the eastern part of Monterey submarine fan and extend from the base of the continental slope near the apex of the fan to the Monterey fan valley. The flow is generally confined between the continental slope and remnants of an older channel (Monterey East fan valley). The hummocky surface of the debris slide and diffuse echo returns from the surface of the nearly acoustically transparent debris flow, as seen in 3.5 kHz profiles, are common to large submarine slides described from passive-margin continental-slope and rise deposits. Piston cores from the Sur slide recovered contorted and sheared fan turbidite units as well as clast- and matrix-supported mudlump debris flows. The cores show that the slide debris is overlain by 0.23–0.87 m of mud and turbidite sand that limit the age of the slide to latest Holocene, although more than one stage of emplacement is possible.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...