Carbonate muds

Shallow water carbonate (reefs carbonate muds) Reservoir quality governed by diagenetic processes and structural history (fracturing). Prolific production from karstified carbonates. High and early water production possible. Dual porosity systems in fractured carbonates. Dolomites may produce H S. 

Table 3.8 lists the arsenic concentrations of different types of marine and estuary sediments from various locations. Overall, low organic-carbon carbonate muds, oxidizing sands, and coarser-grained sediments have relatively little arsenic. In contrast, reducing marine sediments may contain as much as 3000 mg kg-1 of arsenic (Mandal and Suzuki, 2002), 202. Arsenic also tends to be enriched in fine-grained silicate-rich sediments, such as deep-sea clays and marine muds. In most cases, arsenic-rich sediments contain abundant arsenic-accumulating (oxy)(hydr)oxides, organic matter, or sulfides. 

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... 

Walter and co-workers (Walter and Burton, 1990 Walter et al., 1993 Ku et al., 1999) have made extensive efforts to demonstrate the importance of dissolution of calcium carbonate in shallow-water carbonate sediments. Up to — 50% carbonate dissolution can be driven by the sulfate reduction-sulfide oxidation process. In calcium carbonate-rich sediments there is often a lack of reactive iron to produce iron sulfide minerals. The sulfide that is produced by sulfate reduction can only be buried in dissolved form in pore waters, oxidized, or can diffuse out of the sediments. In most carbonate-rich sediments the oxidative process strongly dominates the fate of sulfide. Figure 6 (Walter et al., 1993) shows the strong relationship that generally occurs in the carbonate muds of Florida Bay between total carbon dioxide, excess dissolved calcium (calcium at a concentration above that predicted from salinity), and the amount of sulfate that has been reduced. It is noteworthy that the burrowed banks show much more extensive increase in calcium than the other mud banks. This is in good agreement with the observations of Aller and Rude (1988) that in Long Island Sound siliciclas-tic sediments an increased bioturbation leads to increased sulfide oxidation and carbonate dissolution. 

Shallow marine environments include coral and algal reefs as well as other bioherms and many favour calcification by benthic fauna. Stromatolites and stromatolitic environments are also typical shallow marine formations. The shallow marine carbonate environment may be subdivided into more or less agitated waters with dominantly benthic fauna, calm shallow areas with carbonate muds (e.g. Bahama Banks) with ooids as typical forms of deposits and reef areas with their complicated patterns of calcification and deposition (Bathurst, 1975 Kinsey and Davies, Chapter 2.5). 

Microcrystalline fabric (Figure 7.6C), not to be confused with the randomly orientated crystals of carbonate mud-micrite textures, has been discriminated from columnar fabric on the basis of the irregular stacking of crystallites and the high density of crystal defects. It has been observed in annually laminated alpine stalagmites, where it forms milky, opaque and porous layers. The misorientation of some crystallites with respect to their substrate yields composite crystals with serrated to interfingered... 

Although abundant skeletal bioclastic fragments play an important part in the development of calcite-cemented sandstones, they should not be considered as the only source of such cements. Evidence for this is the common presence of calcite-cemented sandstones in Precambrian sequences. Additional evidence is the absence of bioclastic carbonates in Jurassic sandstones with strata-bound calcite cements (Bjorkum Walderhaug, 1993 Prosser et al., 1993). This suggests that other sources such as sea water and carbonate mud... 

Micrites are limestones originating from carbonate mud or silt. 

The muddy textures (mudstone-wackestone with mud-supported / grains siqiported texture) are characterized by two primary pore-types intramatrix (within carbonate mud) ai intragranular of small size (carbonate grains). Their pore n wmks are monomodal, with low porosity-low perm ility trends. In this Uthofodes the reservoir properties are nudnly controlled by muddy matrix size. 

The sweetened off pressure-treated filter cake of the carbonization mud from beet as well as cane processing is to be used as agricultural soil fertilizer. Cane filter cake is also used for fuel, manure, cane wax, dye-stuffs, metal polish. 

Juice nitration and purification Pulp particles are filtered off, and the raw juice is treated in a two-step process with slaked lime and then carbonated by introduction of carbon dioxide. This procedure serves to neutralize and remove acids and colloids, to destroy nonsucrose components and to remove excess lime. Finally, the carbonation mud is filtered off. The thin juice contains 11-14% sucrose. Finther purification may be achieved by ion exchange treatment. 

Yield 100 kg fresh beet can be worked up to 12-15 kg sucrose, 3.5 kg molasses, 4.5 kg dried pulp (cossettes), and varying amounts of carbonization mud (filter cake). 

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