Diagenesis sedimentary

Neumeier, U. (1999) Experimental modelling of beachrock cementation under microbial influence. In Camoin, G.F. (Ed.) Microbial Mediation in Carbonate Diagenesis. Sedimentary Geology 126, 35-46. 

Matthew RK (1968) Carbonate diagenesis Equihbration of sedimentary mineralogy to the subaerial environement coral cap of Barbados, West Indies. J Sed Petrol 38 1110-1119 McCulloch MT, Esat T (2000) The coral record of last interglacial sea levels and sea surface temperatures. ChemGeol 169 107-129... 

Once the radionuclides reach the sediments they are subject to several processes, prime among them being sedimentation, mixing, radioactive decay and production, and chemical diagenesis. This makes the distribution profiles of radionuclides observed in the sediment column a residuum of these multiple processes, rather than a reflection of their delivery pattern to the ocean floor. Therefore, the application of these nuclides as chrono-metric tracers of sedimentary processes requires a knowledge of the processes affecting their distribution and their relationship with time. Mathematical models describing some of these processes and their effects on the radionuclide profiles have been reviewed recently [8,9,10] and hence are not discussed in detail here. However, for the sake of completeness they are presented briefly below. 

Diagenesis is the set of processes by which sediments evolve after they are deposited and begin to be buried. Diagenesis includes physical effects such as compaction and the deformation of grains in the sediment (or sedimentary rock), as well as chemical reactions such as the dissolution of grains and the precipitation of minerals to form cements in the sediment s pore space. The chemical aspects of diagenesis are of special interest here. 

Bethke, C. M., M.-K. Lee and R. F. Wendlandt, 1992, Mass transport and chemical reaction in sedimentary basins, natural and artificial diagenesis. In M. Quintard and M. S. Todorovic (eds.), Heat and Mass Transfer in Porous Media. Elsevier, Amsterdam, pp. 421 —434. 

Runnells, D. D., 1969, Diagenesis, chemical sediments, and the mixing of natural waters. Journal of Sedimentary Petrology 39, 1188-1201. 

V Diagenesis refers to the sum total of processes that bring about charges in sediment or sedimentary rock subsequent to deposition in water. The processes may be physical or chemical or biological in nature and may occur at any time (Berner, 1986). 

Measurements of radionuclides and metals in marine sediments and particulate matter are conducted for a variety of purposes, including the determination of sedimentation rates, trace metal and radionuclide fluxes through the water column, enrichment of metals in specific phases of the sediments, and examination of new sedimentary phases produced after sediment deposition. Such studies address fundamental questions concerning the chronology of deep-sea and near-shore sedimentary deposits, removal mechanisms and cycling of metals in the ocean, and diagenesis within deep-sea sediments. 

Following burial, marine sediments are recycled via two pathways a crustal route or a mantle route. In the crustal route, burial followed by diagenesis, catagenesis, and metagenesis transfers sediments into either sedimentary or metamorphic rocks. These rocks are eventually uplifted onto land by crustal motions associated with plate tectonics. In the mantle recycling route, sediments and sedimentary rocks are subducted at... 

In order to determine the source composition of sediments using trace elements, it is necessary to ascertain that the element is immobile under conditions of diagenesis and weathering (Spalletti 2008). Several ratios and plots may be used to define the source rocks. The felsic source rock compositions are found in the Co/Th vs. La/Sc diagram (Fig. 3 Table 1). Other trace element characteristics of sedimentary rocks also place some constrains on the nature of the source rock. Floyd Leveridge (1987) used a La/Sc vs. Hf plot to discriminate between different source compositions. In this plot, most data fall in the felsic source to mixed felsic/basic source field (Fig. 4 Table 1). 

During conversion of goethite to hematite only small fractionation effects seem to occur, because most of the oxygen remains in the solid (Yapp 1987). Thus, in principle it should be possible to reconstruct the sedimentary environment of iron oxides from Precambrian banded iron formations (BIF). By analyzing the least metamorphosed BlFs, Hoefs (1992) concluded, however, that the situation is not so simple. Infiltration of external fluids during diagenesis and/or low temperature metamor-... 

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