0000000000643325
AUTHOR
Anika C. Conrad
Refining the temperature dependence of the oxygen and clumped isotopic compositions of structurally bound carbonate in apatite
Abstract Clumped isotope data from carbonated apatite from in vivo and in vitro samples are presented to refine the relationship between mineral growth temperature and carbonate clumped isotopic composition (Δ47). Δ47, δ18O and δ13C data were obtained from phosphoric acid digestion (T = 110 °C) of chemically untreated teeth from an African elephant, Greenland sharks, sand tiger sharks and synthetic apatites. These data cover a temperature range between 1 °C and 80 °C and enlarge the calibration dataset presented in Wacker et al. (2016) by a factor of five. Taxon-specific analyses of tooth enamel(oid) and dentine reveal that both tissues show identical Δ47 values even though the content of o…
Clumped isotope thermometry of carbonate-bearing apatite: Revised sample pre-treatment, acid digestion, and temperature calibration
Abstract It has recently been shown that the clumped isotopic composition (Δ47) of carbonate-bearing hydroxyapatite (CHAP) from teeth and bones reveals important information about the body temperature of vertebrates (Eagle et al., 2010, 2011). In this study we reinvestigate the temperature dependence of Δ47 in CHAP, extending the temperature range from 2 to 59 °C. In addition, the effects of chemical pre-treatment of CHAP on its bulk and clumped isotopic composition are studied. CHAP is best reacted with phosphoric acid at 90 to 110 °C minimizing the potential of evolved CO2 or reaction intermediates to re-equilibrate with traces of water in the acid environment. Reaction at 110 °C ensures …