Diamonds isotopic composition

Fig. 18-23 Observed correlation of isotopic composition of precipitation with ground temperature (gray diamonds Jouzel et ah, 1987), and predictions of simple isotopic models. A, prediction with constant a B, prediction with temperature-dependent a.

Figure All.l. A plot of the difference (residuals) between observed collagen 5 C values and values calculated from the DIFF for dp = +5, dn = +2, and f(F) = F , as a function of the dietary protein carbon content. Due to the eombination of eomposition and manipulated isotopic compositions of the different diets, some diets test the predictions of the DIFF more precisely than others. These are represented as squares (the remainder are represented as diamonds). Although the differenee has been minimized, it is not zero. Nevertheless, and especially for the more reliable reetangular points, the differenee is small, for a wide range of diets and collagen 8 values. Other combinations of dp, ds. and 1(F) give greater residuals.

Fig. 2.57. Pb isotopic compositions in volcanogenic Cu sulfide deposits in Japan. Diamond shape K], K2 and K3 indicate average values of Kuroko-type deposits Ki Taro (Cretaceous) K2 Northeast Japan (Miocene) K3 southwest Japan (Miocene). Note that the Shimokawa ores (solid square, Besshi subtype) and Yanahara ores (open square, Hitachi subtype), closely associated with sediments, tend to have slightly more radiogenic values than the others (solid circles) (Sato and Kase, 1996).

Figure 12. Extent of dissolution and re-precipitation between aqueous Fe(III) and hematite at 98°C calculated using Fe-enriched tracers. A. Percent Fe exchanged (F values) as calculated for the two enriched- Fe tracer experiments in parts B and C. Large diamonds reflect F values calculated from isotopic compositions of the solution. Small circles reflect F values calculated from isotopic compositions of hematite, which have larger errors due to the relatively small shifts in isotopic composition of the solid (see parts B and C). Curves show third-order rate laws that are fit to the data from the solutions. B. Tracer experiment using Fe-enriched hematite, and isotopically normal Fe(lll). C. Identical experiment as in part B, except that solution Fe(lll) is enriched in Te, and initial hematite had normal isotope compositions. Data from Skulan et al. (2002).

Ott U (1993) Physical and isotopic properties of surviving interstellar carbon phases. In Protostars Planets III. Levy Hand Lunine JI (eds) University of Arizona Press, Tucson, p 883-902 Ott U (1996) Interstellar diamond xenon and timescales of supernova ejecta. Astrophys J 463 344-348 Ott U, Begemann F, Yang J, Epstein S (1988) S-process krypton of variable isotopic composition in the Murchison meteorite. Nature 332 700-702... 

Virag A, Zinner E, Lewis RS, Tang M (1989) Isotopic compositions of H, C, and N in C8 diamonds from the Allende and Murray carbonaceous chondrites. Lunar Planet Sci XX 1158-1159 Volkening J, Papanastassiou DA (1989) Iron isotope anomalies. Astrophys J 347 L43-L46 Volkening J, Papanastassiou DA (1990) Zinc isotope anomalies. Astrophys J 358 L29-L32 Wadhwa M, Zinner EK, Crozaz G (1997) Manganese-chromium systematics in sulfides of unequilibrated enstatite chondrites. Meteorit Planet Sci 32 281-292... 

Figure 19. Plot of Li isotopic composition vs. inverse Li concentration for lakes and basinal/oilfield brines. Lakes open circle = major global lakes (Chan and Edmond 1988 Falkner et al. 1997) semi-open circle = western U.S. closed basin lakes (Tomascak et al. 2003). Oilfield brines inverted triangle = Williston basin, Saskatchewan (Bottomley et al. 2003) diamond = Israeli oilfields (Chan et al. 2002d). Mine waters (Canadian Shield basinal brines) square = Yellowknife, NWT (Bottomley et al. 1999) triangle = Sudbury, Ontario, area (Bottomley et al. 2003) star = Thompson, Manitoba, area (Bottomley et al. 2003). Average composition of seawater is included for reference.

Boyd SR, PUlinger CT, Mflledge HJ, Mendelssohn MJ, Seal M (1992) C and N isotopic composition and the infrared absorption spectra of coated diamonds evidence for the regional uniformity of CO2-H2O rich fluids in lithospheric mantle. Earth Planet Sci Lett 109 633-644... 

Deines P, Haggerty SE (2000) Small-scale oxygen isotope variations and petrochemistry of ultradeep (>300 km) and transition zone xenohths. Geochim Cosmochim Acta 64 117-131 Deines P, Gurney JJ, Harris JW (1984) Associated chemical and carbon isotopic composition variations in diamonds from Finsch and Premier Kimberhte, South Africa. Geochim Cosmochim Acta 48 325-342... 

Standard states. The standard or reference state of each of the elemental substances is taken to be that physical state (or one of them, if there are two or more) in which the element naturally exists at a pressure, or a fugacity, of one atmosphere and at a temperature of 18°. The isotopic composition of each element in its standard state is understood to be the naturally existing one. For the element carbon, we have selected its form as diamond, C (c, diamond), as the standard state because no other form of solid carbon is at present a reproducible and invariable one. 

Figure 19. Comparison of Miocene wet season average bivalve isotopic compositions from Dettman et al. (2001) (dark gray squares) with averaged soil carbonate compositions from Bakia Khola (gray diamonds) reported by Harrison et al. (1993) from the Siwaliks. The difference between these is taken as a measure of A(818Omw) and hence can be used to estimate the precipitation weighted hypsometric mean elevations of drainages sampled by the bivalve shells. Note that in modem world the wet season amount weighted mean...

Figure 6. Topography (solid), precipitation (gray), and 8180 and 8D values along a transect across the southern South Island of New Zealand. The modern Southern Alps create a strong rain shadow on the eastern side of the mountain range that is characterized by a reduction in rainfall from up to 3000 mm/a on the western side to values <300 mm/a on the eastern side of the range. Similarly, hydrogen and oxygen isotopic compositions of meteoric water are strongly depleted in D and 180, and decrease by ca. —40%o and -4.5%o, respectively. Circles SlsO values, diamonds 8D values. Data from Chamberlain et al. (1999) and Stewart et al. (1983). After Chamberlain et al. (1999).

C60 has not yet been detected in primitive meteorites, a finding that could demonstrate its existence in the early solar nebular or as a component of presolar dust. However, other allotropes of carbon, diamond and graphite, have been isolated from numerous chondritic samples. Studies of the isotopic composition and trace element content and these forms of carbon suggest that they condensed in circumstellar environments. Diamond may also have been produced in the early solar nebula and meteorite parent bodies by both low-temperature-low-pressure processes and shock events. Evidence for the occurrence of another carbon allotrope, with sp hybridized bonding, commonly known as carbyne, is presented. 

Figure 6.13 Kr isotopic ratios in MORB, OIB, diamond, and mantle xenolith are plotted as percentage deviation from the air Kr isotopic composition. MORB Hiyagon et al. (1992). OIB Hiyagon et al. (1992). Diamond Ozima and Zashu, 1991. Xenolith Poreda and Farley (1992). N number of data analyzed.

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