Mineral exchange

Many more high-precision whole-rock analyses of both Mg and O isotope ratios for chondrite components would help to establish whether or not the mixing trends in Figure 15 are valid, or even if the concept of mixing is useful. Bulk objects are desirable because their isotopic compositions are not affected by secondary inter-mineral exchange reactions that are know to be important for both the Mg and O isotopic systems in CAIs and chondrules. 

Ion-exchange processes on clay minerals moving from riverwater to seawater (Section 6.2.3) remove about 26% of the river flux of Na+ to the oceans and are significant removal processes for K+ and Mg2+ (Table 6.3). To balance this removal, clay minerals exchange a significant amount of Ca2+ to the oceans, adding an extra 8% to the river flux (Table 6.3). These modern values are,... 

The theoretical models of inter-mineral and intra-mineral exchange provide a foundation for the interpretation of fractionation data for thermometry. However,... 

Here the rate, of the k fluid-mineral exchange reaction is compared to the pore velocity of the fluid, Vp. A high Damkohler I number implies fast reaction kinetics... 

There are several causes of the generally poor correlation between the extractable quantity of a heavy metal and soil pH or availability to plants. Varying amounts of carbonates, organic matter, hydrous oxides of manganese and iron, as well as soil Eh values all affect the amounts of these metals which are extractable. Much better correlations than those obtained would be expected if the heavy metals were located on clay mineral exchange sites or were complexed by organic matter. 

The fact that in fully mineralized bone the hydration shell is minimized considerably influences the mineral exchanges between bone and plasma and bone composition. 

World Mineral Exchange http //www.niineralszone.coin/minerals/... 

Doherty, S. B., (1990). An Experimental Investigation of Supercritical Alkali Halide Mineral Exchange Equilibria. Master s Degree, Univ. Calif., Los Angeles, 40 pp. 

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