Isotope in carbonate

Gussone N, Eisenhauer A, Heuser A, Dietzel M, Bock B, Bohm E, Spero H, Lea D, Buma J, Nagler, TF (2003) Model for kinetic effects on calcium isotope fractionation (6 Ca) in inorganic aragonite and cultured planktonic foraminifera. Geochim Cosmochim Acta 67 1375-1382 Halicz L, Galy A, Belshaw NS, O Nions RK (1999) High precision measurement of calcium isotopes in carbonates and related materials by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS). J Anal Atom Spectr 14 1835-1838... 

The lead isotope ratios indicate an upper cmstal source for the lead and are consistent with mineralization at 800 Ma. Tracer isotopes in carbonates and chalcocite concentrates indicate that an external fluid altered the dolomitic unit changing its isotopic composition as well as deposited copper mineralisation. 

Figure 19.15. The liquid thermal diffusion system for the recovery of heavy sulfur isotope in carbon disulfide. The conditions prevailing at the time after 90% 34S is reached. Each rectangle in the cascades represents a column, each height being proportional to the length of the column. The two cascades have a combined height of 14 m, annular dia 25.4 mm, and annular width 0.18-0.3 mm. Production rate of 90% concentrate of 34S was 0.3 g/day [IV. M. Rutherford, Ind. Eng. Chem. Proc. Des. Dev. 17, 17-81 (1978)].

Keith, M. L., and Weber, J. N. Systematic relationships between carbon and oxygen isotopes in carbonates deposited by modern corals and algae. Science 150, 498-501 (1965). 

Oxygen isotopes have been the most thoroughly studied isotopes in carbonate mineral systems. There are three stable isotopes of oxygen 160 = 99.763%, 170 = 0.0375% and 180 = 0.1995% (Garlick, 1969). The fractionation of 180 relative to 160 is commonly measured and reported as the value of 8180 relative to a standard. Two standards have been widely used in reporting 8180 values. The most common one in general usage now is "SMOW," which stands for standard mean ocean water. 

One of the most important uses of oxygen isotopes in carbonates is as geothermometers. Isotope fractionation is pressure independent (Clayton et al., 1975), giving it an advantage over other geothermometers which are generally both temperature and pressure dependent. The equation for calculating the temperature at which calcite precipitates from water is ... 

Table 10.2. Factor analyses of the relations among the age curves of strontium isotopes in carbonate, carbon isotopes in carbonate, sulfur isotopes in sulfate, and sea level for the Phanerozoic (from Holser et al., 1988).

Challa S.R., Sholl D.S., Johnson J.K., Adsorption and separation of hydrogen isotopes in carbon nanotubes Multicomponent grand canonical Monte Carlo simulations, J.Chem.Physics, 2002,116(2) 814-824. 

Wachter, E. A. J. M. Hayes, 1985. Exchange of oxygen isotopes in carbon-dioxide-phosphoric acid systems. Chem. Geol. (Isot. Geosci. Sect.) 52 365-374. 

Hansteen, H., and Fisenhauer, A. (2008) An alternative data acquisition and evaluation strategy for improved isotope ratio precision using LA-MC-ICP-MS applied to stable and radiogenic strontium isotopes in carbonates. 

Finally, the use of isotopes in carbon-acid substrates is an invaluable tool for the determination of the stereochemistry of the enzymatic proton transfer. In contrast to organic reactions, stereospecific proton transfers are the rule, rather than the exception, in enzymatic reactions, owing to the inherently asymmetric nature of the protein surface. An example is the pair of isotopic exchange reactions between dihydroxyacetone phosphate and tritiated water catalysed by the enzymes aldolase and triose phosphate isomerase [17]. In the two cases a different a-hydrogen of the ketone is exchanged with water, leading to the two discrete monotritiated derivatives 1 (labelled by the isomerase) and 2 (labelled by the aldolase) ... 

---