Dolomite irregular

The lower unit of the Ohio Shale which is present in the outcrop area of eastern Kentucky is the Huron Member. Primarily, the Huron consists of black to brownish-black to gray-black, laminated, siliceous, OM-rich shales. Calcareous laminae, cone-incone limestone, dolomitic gray shales, dolomite beds and biotur-bated greenish-gray shales occur as interbeds and laminae in the lower parts of the member. Pyrite occurs as framboids, nodules, and irregular forms. 

Dolomite/ankerite D2 occurs as blocky to poikilotopic, irregularly zoned rhombs (90-200 pm) which marginally replace and cover, and thus postdate, D1 (Fig. 7F). Samples cemented mainly by D2 show moderate packing, indicating a dominantly... 

The poikilotopic dolomite cement occurs in irregular patches (Fig. 10A) and locally completely cements the rock (Fig. lOB). The cement is common... 

Gregg, J.M. Hagni, R.D. (1987) Irregular cathodoluminescent banding in late dolomite cements evidence for complex faceting and metalliferous brines. Geol. Soc. Am. Bull., 98, 86-91. 

Due to the presence of variable stoichiometric coefficients, regular and irregular dolomites are distinguished. In regular or stoichiometric dolomite cation and anion layers alternate in the order Ca "- CO3 - Mg "-CO3 - Ca ", etc. The structure of such dolomite is similar to the structure of calcite except that Ca and Mg atoms are positioned in a different layer. 

With irregular dolomite, Ca and Mg in cation positions are not ordered, which is accompanied by a positional disorder in the placement of. Such disordered modification of dolomite is protodolomite, which usually contains more Ca and less Mg compared with the theoretical formula. 

The equilibrium between calcite and irregular dolomite is defined by activities of Ca, Mg and in the solution according to the equation... 

Figure 2.57 Diagram of thermodynamical stability for CaCO -Ca MgfCOD, -H O system (Machel, and Mountjoy, 1986 Braithwaite et al, 2004). Lines (1-3) are experimentally calculated equilibrium between 1. calcite and completely regular dolomite 2. calcite and regular dolomite with small excess of Ca 3. calcite and completely irregular protodolomite.

Thickness of such covers and layers vary from several centimeters to 10-15 meters. So compound conditions caused by 1) irregular alternation of carbonate and terrigenous units, 2) initial and secondary mineral heterogeneity of carbonate rocks (silicification/dolomitization prevent hmestones... 

A wide variety of materials have been classified with the TrtboClassifier with positive results. These include separation of natural from synthetic diamonds, classification of electroluminescent powder, removal of dust from dolomite, removal of irregular shapes from bronze cut wire, removal of Irregular shapes from granules of hard alloys, size classification of calcium carbonate, fly ash, copper particles etc. 

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