Carbonate minerals origin

The most common source is the supersaturation and subsequent scaling of minerals originating in the MU water. Insoluble calcium carbonate in the form of calcite (CaC03) resulting from the thermal decomposition of soluble calcium bicarbonate [Ca(HC03)2] is a classic example. Calcium carbonate quickly forms a white, friable deposit. In addition, the hydrolysis of excess bicarbonate increases... 

Of mineral origin inorganic chemistry is the study of all chemical elements and compounds, except carbon and its compounds certain simple carbon compounds, e.g., oxides and sulphides,... 

The subsurface generally is an open system. The presence of CO and other gases in the atmosphere affects the partial pressure of gas constiments in the subsurface. For example, carbonate mineral dissolution in a system open to atmospheric COj does not achieve equilibrium. However, higher local subsurface CO concentrations can originate from biological activity and other oxidation processes. 

The major components CaO and MgO in dolomite have a minimal range indicative of very small variation in Ca/(Ca+Mg+Fe) ratios, whereas the minor elements such as SrO and MnO have a wide variation. Therefore trace components in carbonate minerals can be used as discriminant parameters to determine the origin of the carbonate rocks (cf. Yang LeBas 2004). Compositional variation of carbonate minerals from Chehelkureh on the basis of MnO or SrO (wt%) versus [Ca/(Ca+Mg+Fe)j (atoms per formula unit, a.f.u.) diagrams (Fig. 4) show that the MnO and SrO contents in dolomite-ankerite are higher than those in siderite-magnesite and accessory calcite. 

A large number of distinct mineral phases have been reported in various coals (Table 5.1), although lists of minerals in coal may contain as many as 50 to 60 minerals, most fall into one of five groups (1) aluminosilicate minerals (clay minerals), (2) sulfide and sulfate minerals, (3) carbonate minerals, (4) silicate minerals (principally quartz), and (5) other minerals that include minerals that may occur in trace amounts or may be specific to a particular coal having originated because of the localized deposition and maturation conditions (Speight, 1994, and references cited therein). 

Whereas the basic principles for calculating the composition of a solution in equilibrium with a carbonate mineral are relatively straightforward, the application of these types of calculations to real world situations is commonly less obvious and fraught with difficulties. Consequently, we will present a series of calculations applied to natural geochemical systems, inspired by those originally... 

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