Muscovite Quartz

Hence, it is assumed that the minerals in equilibrium with geothermal waters are albite, K-feldspar, muscovite, quartz, calcite, anhydrite, chlorite and wairakite. 

Fig. 2.7. Relation between the pH and CP concentration of geothermal waters. The solid line indicates the albite-K-feldspar-muscovite-quartz-solution equilibrium at 250°C. For symbols used see caption to Fig. 2.2. (Shikazono, 1978a).

Fig. 2.8. Relation between the Ca and CR concentrations of geothermal waters and inclusion fluids. Solid lines indicate (1) albite-K-feldspar-muscovite-quartz-caleite-solution equilibrium at OHaCOs = 10 (2) albite-K-feldspar-muscovite-quartz-calcite-solution equilibriumn at oh2C03 = 10 (3) anhydrite-solution at SSo (total dissolved sulfate concentration) = 10 and (4) anhydrite-solution equilibrium at SSq = 10. For symbols used see caption to Fig. 2.2 (Shikazono, 1978a).

Fig. 25.1. Mineralogical consequences of mixing the two fluids shown in Table 25.1 at 60 °C in the presence of microcline, muscovite, quartz, and dolomite. Results shown as the volume change for each mineral (precipitation is positive, dissolution negative), expressed per kg of pore water.

Kerrick D. M. (1972). Experimental determination of muscovite + quartz stability with P(H20) < P (total). Amer. Jour. Set, 272 946-958. 

Oxygen thermometry for minerals in igneous and metamorphic rocks was surveyed by Epstein and Taylor (1967). These authors reviewed older analytical and experimental work and showed how useful many equilibrium silicate and oxide pairs (quartz-muscovite, quartz-magnetite, quartz-gamet among many others) can be for recalculation of equilibration temperatures. 

In the /iXRF map at spot 2 both Pb and Fe are present however, no Pb mineral species are identified in the /tXRD pattern collected from that area. Instead, the tXRD pattern is dominated by muscovite, quartz, calcite, poorly crystalline iron oxides and peaks attributed to unidentified alumino-sificates. We attribute the absence of a Pb mineral phase in a region of the pXRF map where Pb XRF counts... 

KAl2[Si3A10io](OH)2 + Si02 — KAlSi30g -I- Al2Si05 -I- H2O Muscovite Quartz K-feldspar Sillimanite... 

The solid line indicates the aibite-K-feidspar-muscovite-quartz-solution equilibrium at 250 °C (Shikazono 1978a, b). 

Alnmiiiium group Strontium group Bauxite Kaolinite Muscovite Quartz... 

Lead group Tungsten group Albite Barium tungstate Lead tungstate Muscovite Quartz Raspite Scheelite Tungsten white Bersch (1901) 128 Bywater(1983) Kilias Konnerup-Madsen (1997) Plakhov et al. (1971) Riffault et al (1874) 159-160 Salter (1869) 414 15... 

KAl2(AlSi20 Q)(0H)2 + SiO = KAlSi Og + Al SiO + H O (2T), muscovite quartz sanidine andalusite steam... 

The columns reacting the muscovite/quartz mixture with the young (Na-K-Ca-OH) fluid showed a similar pattern to that of the albite columns. 

The predicted reaction of the muscovite/ quartz mixture with the evolved fluid was much simpler than the above. Dissolution was predicted to take place along the entire length of the column but at about half the rate found with the young fluid, and with more variation between the inlet and outlet ends. The only products expected to be found in this experiment were hillebrandite, which was predicted to form over the first 240 mm of the column, and foshagite, predicted to form from then on. It was predicted that there would be small net reductions in the porosity throughout the column. 

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