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Relict sediments

Coral reefs and mangrove swamps Modern lithogenous sediment Relict sediment (continental shelf)... [Pg.517]

Relict sediment Sediments that are no longer forming. Most of the sediments on the continental margins are presently relict. Some are even eroding. [Pg.886]

Approximately 70 % of the continental shelf surface is covered with relict sediment, i.e. sediment deposited during the last glacial period under conditions different from today s, especially at times when the sea level was comparatively low (Emery 1968). It has to be assumed that there is a kind of textural equilibrium between these relict sediments and recent conditions. The fine-grained constituents of shelf sediments were eluted during the rise of the sea level in the Holocene and thereafter deposited, over the edge of the shelf onto the upper part of the continental slope, so that extended modem shelf surface areas became covered with sandy relict sediment (Milliman et al. 1972 Milliman and Summerhays 1975). [Pg.17]

Emery, K.O., 1968. Relict sediments on continental shelves of the world. Bull. Am. Assoc. Petrol. Geologists, 52 445-464. [Pg.25]

McManus, D.A. 1975. Modern versus relict sediment on the continental shelf. Geological Society of America Bulletin, 86 1154-1160. [Pg.495]

Where the waves and currents weaken, resuspended sediment settles back down to the seafloor. Given the small particle sizes of the suspended material (mostly 3 to 10 pm), redeposition can take many years. The resulting redistribution of sediments creates patches of clay, mud, and exposed rock on the continental margins. In other words, resuspension from waves and currents can cause some sediments to become reUct deposits. Hard bottoms can serve as good habitats for some members of the benthos as they promote the formation of coral reefs. For paleoceanographers, relict deposits are problematic because they represent gaps, or imconformities, in the sedimentary record. [Pg.347]

Compositional and isotopic studies have shown that a wide range of organic materials are sequestered in marine sediments. These include direct or indirect products of marine photoautotrophy, vascular plant debris, and relict OC derived from sedimentary rock weathering. [Pg.3016]

Carbonate sediments can be subdivided into skeletal and nonskeletal components. Nonskeletal carbonate grains have been divided into five major types mud, pellets, ooids, lithoclasts, and relict. Carbonate muds are common deposits in low-energy environments, such as tidal flats and subtidal areas. Pellets are formed by the ingestion of sediment by marine organisms and excretion... [Pg.3541]

The trapping of pore fluids as sediments are buried may potentially preserve fluid from a time when ocean composition differed from the present, such as the last glacial period when salinity should have been greater than at present and the isotopic composition of water should have been heavier. However, pore water is an open system, and diffusion facilitates the re-equilibration between fossil pore water and bottom waters. Consequently, relict signals may be difficult to detect, even in the absence of any influence of diagenetic reactions. [Pg.382]

The Changjiang River-derived sediments are mostly confined to the south and seasonally transported offshore by a plume event. The east of the Changjiang River mouth is covered with sandy sediments, either relict sands of the continental shelf or an active offshore tidal sand sheet. [Pg.33]


See other pages where Relict sediments is mentioned: [Pg.331]    [Pg.344]    [Pg.519]    [Pg.50]    [Pg.502]    [Pg.331]    [Pg.344]    [Pg.519]    [Pg.50]    [Pg.502]    [Pg.517]    [Pg.520]    [Pg.85]    [Pg.327]    [Pg.336]    [Pg.65]    [Pg.104]    [Pg.182]    [Pg.441]    [Pg.180]    [Pg.814]    [Pg.2998]    [Pg.2999]    [Pg.3002]    [Pg.3025]    [Pg.3250]    [Pg.3541]    [Pg.4465]    [Pg.176]    [Pg.4]    [Pg.30]    [Pg.65]    [Pg.84]    [Pg.95]    [Pg.126]    [Pg.445]    [Pg.112]    [Pg.374]    [Pg.123]    [Pg.314]    [Pg.3]    [Pg.341]    [Pg.60]    [Pg.387]    [Pg.584]   
See also in sourсe #XX -- [ Pg.344 ]




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