Metamorphic water

The equation for an open system through which the water makes only a single pass is given, Taylor (1977) by  

Calculation of water/rock ratio from the equations of Taylor (1974, 1977) 

Final rock composition 5 0 = -4.0 Vm Initial fluid composition 5 0 - -14.0 Vie 

The equation for plagioclase (Ansol-water exchange, from Table 7.2, is  

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Connate water Water trapped in a sedimentary rock when its sediments were originally deposited. In most cases, the origin(s) of saline water in sedimentary rocks cannot be determined and they are simply identified as formation waters (compare with meteoric, juvenile, magmatic, and metamorphic waters). 

Metamorphic water Water that is expelled from minerals during metamorphism. 

In nature the Fe-rich illites (glauconite and celadonite) appear to progress from the lMd to the 1M polytype. The Al-rich illites are predominantly the lMd and 2M varieties. If the 1M polytype is an intermediate phase, it is surprising that it is not more abundant in sediments. Recent studies of unmetamorphosed Precambrian sediments (Reynolds,1963 Maxwell and Hower,1967) have shown that the lMd polytype is relatively abundant in ancient sediments, particularly in the extremely fine fraction. The senior author has noted the relative abundance of the lMd polytype in the fine fraction of most Paleozoic rocks but has considered most of it to be mixedlayered illite-montmorillonite rather than illite. Weaver (1963a), Reynolds (1965), and Maxwell and Hower (1967) have shown that during low-grade metamorphism water is squeezed from the expanded layers and the lMd polytype is transformed into the stable 2M polytype. 

Continuous sedimentation forms a layer of deposition which comes towards its base under increasing pressure and temperature with increasing load. The average gradient of rising pressure and temperature with depth is 0.3 kb km and 20 °C km respectively. Only minor chemical reactions occur in the majority of sediments up to temperatures of 200 °C. In the range of 300 to 800 °C, former sediments approach new equilibria by various reactions this process is called regional metamorphism. Water in the porous volume of rocks activates these mate-... 

Meteoric water Magmatic water Metamorphic water... 

Soil water flow is decidedly episodic. During dry times the water solutions in the soil are probably fairly concentrated and not very reactive. Time-averaged reaction rates should be roughly proportional to the fraction of time reacting minerals are in contact with thermodynamically imdersaturated (and reactive) water. In a study of the relationship between denudation rate and runoff for rivers draining igneous and metamorphic rock in Kenya, Dunne (1978) obtains the relationship of (denudation rate in tons/km per year) = 0.28 (runoff in mm/ year)°. ... 

The sediment reservoir (1) represents all phosphorus in particulate form on the Earth s crust that is (1) not in the upper 60 cm of the soil and (2) not mineable. This includes unconsolidated marine and fresh water sediments and all sedimentary, metamorphic and volcanic rocks. The reason for this choice of compartmentalization has already been discussed. In particulate form, P is not readily available for utilization by plants. The upper 60 cm of the soil system represents the portion of the particulate P that can be transported relatively quickly to other reservoirs or solubilized by biological uptake. The sediment reservoir, on the other hand, represents the particulate P that is transported primarily on geologic time scales. 

Soil is a mixture of solid materials, air and, usually, water and organic matter. The radium content of soil often reflects that of the rocks from which the solid materials are derived by physical and chemical activity. The observed ranges are from 0 to 20 Bq kg for ultrabasic rocks (dunite) to 1 to 1835 Bq kg for igneous metamorphic rocks (gneiss) (Wollenberg, 1984). While these ranges are broader than those for measured for soils, the mean values for rocks, excluding alkali rocks, is consistent with the means observed for soils. 

The names of van t Hoff, Arrhenius, Ostwald, and Nernst dot the pages of Van Hise s work and with good reason. His understanding of the effects of temperature and pressure on chemical reactions and of the roles of water and ionic equilibria in metamorphic processes was derived largely from his reading of the work of these physical chemists. "The handling of the problems of rock alteration with fairly satisfactory results," he later wrote, "was possible because of the rise of physical chemistry. 

The importance of aqueous solutions in geochemistry can be appreciated if we recall that two-thirds of the surface of our planet is covered by water and that aqueous fluids of various salinities are determinant in the development of volcanic and metamorphic processes in the earth s upper mantle and crust. 

Mel nik Y. P. (1972). Thermodynamic parameters of compressed gases and metamorphic reactions involving water and carbon dioxide. Geochem. Int., 9 419-426. 

Carbon and oxygen isotopic analyses show that marbles from the Iratsu and Tonaru areas in the Sambagawa metamorphic belt have 6 Cpdb values close to zero, similar to most marine carbonates. These data suggest that these marbles have precipitated from sea water. 

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