Sediment deltaic

Bushinskiy GI (1964) On shdlow water origin of phosphorite sediments, deltaic and shallow marine deposits. Develop Sediment 1 62-70... 

Since faults are zones of inherent weakness they may be reactivated over geologic time. Usually, faulting occurs well after the sediments have been deposited. An exception to this is a growth feu/f (also termed a syn-sedimentary fault), shown in Figure 5.7. They are extensional structures and can frequently be observed on seismic sections through deltaic sequences. The fault plane is curved and in a three dimensional view has the shape of a spoon. This type of plane is called listric. Growth faults can be visualised as submarine landslides caused by rapid deposition of large quantities of water-saturated... 

Growth faulted deltaic areas are highly prospective since they comprise of thick sections of good quality reservoir sands. Deltas usually overlay organic rich marine clays which can source the structures on maturation. Examples are the Niger, Baram or Mississippi Deltas. Clays, deposited within deltaic sequences may restrict the water expulsion during the rapid sedimentation / compaction. This can lead to the generation of overpressures. 

Sediment reference materials should be developed for both open-ocean and coastal areas. Open-ocean sediments should include carbonate-rich, silicate-rich, and clay mineral-rich types. Coastal sediments should be of the same types and should include a deltaic sediment that has not been in contact with seawater. Taken together with the algal-based materials, these sediment materials would represent a wide range of diagenetic states. The committee recommends that each of these solid... 

Deltaic sediment-based reference material (that has not contacted seawater). 

Corroded quartz grains have been reported in association with chert in modern carbonates (Bartholome, 1966), and they are known to occur in sand and salt deposits (Dapples, 1959, 1962 Braitsch, 1971). Chalcedony is found associated with quartz in marine sediments formed from devitri-fied glass (Muller, 1961). Amorphous silica is common in recent ocean sediments (Biscaye, 1965 High and Picard, 1965 Calvert, 1971) and has also been identified in deltaic terriginous sediments (Millot, 1964). 

FRE1DMAN (G.M.) and GAVISH (E.), 1970. Chemical changes in intersticial waters from sediments of lagoonal, deltaic, river,estuarine and salt water marsh and cove environments. Journ. Sed. Petr. 40, 930-53. 

Figure 13.19 Depth profiles of ECO2 and

Coleman, J.M., and Gagliano, S.M. (1964) Cyclic sedimentation in the Mississippi River deltaic plain. Trans. Gulf Coast Assoc. Geol. Soc. 14, 67-80. 

The effect of waves on the seashores, including the delta coasts, depends on the energy of waves. Waves are capable of destroying the deltaic deposits in the periods of low sediment load and to slow down the progradation of deltas into the sea, as well as to transport sandy sediments along the delta coastlines and to form beaches and sand coastal bars. In some cases, separate deltaic lobes were completely destroyed after the water and sediment input to the deltas had ceased (the deltas of the Danube, Rioni rivers). 

Amazon deltaic deposits are reworked extensively by tides and waves (Geyer et al. 1996, Kineke et al. 1996, Sternberg et al. 1996). Over 10% of the Amazon subaqueous delta is covered by fluid muds (suspended solid concentration > 10 g L O, which can be several meters thick in some places. These sediments and the water contained therein can be mobilized by changes in frontal dynamics or by fortnightly tidal cycles (Kineke et al. 1996, Geyer et al. 1996). Even in nonfluid mud areas, the sediment can be... 

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