Carbonate thermometry

Ge resistors are specifically produced for low-temperature thermometry carbon and Ru02 resistors are commercial products for electronics. Pure carbon is not a semiconductor. The negative slope R(T) is due to the production process which consists in pressing and sinterization of carbon particles with glue. The resulting resistance is probably determined by the contact resistance between the particles. The cost of the carbon resistor thermometer is very low. Manufacturers such as Speer, Allen-Bradley and Matsushita have produced in the past carbon resistors for many years. Most of firms have now ceased manufacture, although their products may still be found in the storerooms of research laboratories. 

Kitchen NE, Valley JW (1995) Carbon isotope thermometry in marbles of the Adirondack Mountains, New York. J metamorphic Geol 13 577-594 Kiyosu Y, Krouse HR (1990) The role of organic acid in the abiogenic reduction of sulfate and the sulfur isotope effect. Geochem J 24 21-27... 

Carbonate clumped isotope thermometry is based on the temperature dependence of the abundances of bonds between 13C and lsO in carbonate minerals. This temperature sensitivity stems from the fact that isotope exchange reactions such as ... 

Figure 12. Apparent growth temperatures for various Altiplano carbonates based on clumped isotope thermometry, plotted as a function of estimated maximum burial depth. Symbols discriminate among soil carbonates from sections near Callapa, Corque and Salla and lacustrine carbonates from near Tambo Tambillo, as indicated by the legend. The heavy solid line indicates an estimated burial geotherm, assuming a surface temperature of 20 °C and a gradient of 30 °C per km. The dashed lines define a 10° offset from this trend, which we consider a reasonable estimate of its uncertainty. Carbonates deposited within the last 28.5 Ma and buried to 5000 meters or less exhibit no systematic relationship between apparent temperature and burial depth, and show no evidence for pervasive resetting of deeply buried samples. Error bars are la (when not visible, these are approximately the size of the plotted symbol).

Similar to the catalyst of the catalytic thermometry sensor, the catalytic activity of the CTL-based sensor depends not only on the kind of catalyst material and the surface-to-volume ratio of the powder but also on the preparation procedure of the powder. In considering these conditions, a detailed comparison of the CTL catalytic activity has not been reported so far. The present authors and coworkers observed the CTL emission by ethanol vapor on y-aluminum oxide, barium sulfate, calcium carbonate, and zirconium oxide at a few hundred degrees. On the other hand, CTL emission is not observed during the catalytic oxidation on metal and semiconductive materials, e.g., tin oxide, zinc oxide, and copper oxide. 

Kitchen NE, Valley JW (1995) Carbon isotope thermometry in marbles of the Adirondack Mountains, New York. J Metam Geol 13 577-594... 

Wada H, Suzuki H (1983) Carbon isotopic thermometry cahbrated by dolomite-calcite solvus temperatirres. Geochim Cosmochim Acta 47 697-706. 

The organization of this paper will be to discuss the assumptions of thermometry, processes of isotope exchange, and approaches for recovering temperature estimates of identifiable geological events. This is followed by applications of oxygen and carbon isotope thermometry to metamorphic and igneous rocks. While many careful studies have been published since 1947, emphasis will be placed on studies that have benefited from technical, experimental, and theoretical advances of the past decade. 

Figure 19. Carbon isotope thermometry for Adirondack marbles. (19A) Plot of 8 C(calcite) vs. 5 C(graphite). Open symbols are for upper the amphibolite facies NW Adirondacks and closed symbols are for the granulite facies Adirondack Highlands. (19B) Values of A(Cc-Gr) in per mil and resulting isopleths for 675°C parallel the strike of the terrane and, show lower metamorphic temperatures centered on Gouvemeur and increasing towards granulite facies rocks to the SE and to NW. Note outcrop tests at Fish Creek (FC), the Train Wreck (TW) and the Valentine Mine (VM) (from Kitchen and Valley 1995).

Morrison J, Barth AP (1993) Empirical tests of carbon isotope thermometry in granulites from southern California. J Metamor Geol 11 789-800... 

Duim SR, Valley JW (1992) Calcite-graphite isotope thermometry a test for polymetamorphism in marble, Tudor gabbro aureole, Ontario, Canada. J Metamorph Geol 10 487-501 Eiler JM, Mojzsis SJ, Arrhenius G (1997) Carbon isotope evidence for early life. Nature 396 665 Elderfield H, Schultz A (1996) Mid-ocean ridge hydrothermal fluxes and the chemical composition of the ocean. Aim Rev Earth Planetary Sci 24 191-224... 

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