Conodont apatite d88/86Sr and d44/40Ca compositions and implications for the evolution of Palaeozoic to early Mesozoic seawater
© 2017 Elsevier B.V. We present high precision (TIMS double spike) stable isotope measurements of both d44/40Ca and d88/86Sr together with radiogenic87Sr/86Sr ratios determined from conodont apatite. These data represent five intervals ranging from the early Ordovician to late Triassic. The conodont...
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| Format: | Journal Article |
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Elsevier Science BV
2017
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| Online Access: | http://hdl.handle.net/20.500.11937/70982 |
| _version_ | 1848762357475442688 |
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| author | Le Houedec, S. McCulloch, M. Trotter, J. Rankenburg, Kai |
| author_facet | Le Houedec, S. McCulloch, M. Trotter, J. Rankenburg, Kai |
| author_sort | Le Houedec, S. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © 2017 Elsevier B.V. We present high precision (TIMS double spike) stable isotope measurements of both d44/40Ca and d88/86Sr together with radiogenic87Sr/86Sr ratios determined from conodont apatite. These data represent five intervals ranging from the early Ordovician to late Triassic. The conodont d44/40Ca values (relative to NIST 915a) range from - 0.47‰ to + 0.15‰, with an apparent shift to more positive values between the early Silurian and late Devonian/early Carboniferous, similar to the brachiopod-based marine d44/40Ca record (Farkaš et al., 2007a). We calculated a d44/40Ca seawater-bio-apatite fractionation factor of about - 1.9‰, which allowed us to reconstruct a palaeo-seawater d44/40Ca record from bio-apatites. Despite a slightly positive offset of about + 0.2 to + 0.5‰, the d44/40Ca record obtained from bio-apatites is consistent with the previously reported d44/40Ca seawater record inferred from carbonates. We find that unlike the carbonate d44/40Ca records, the d88/86Sr measurements from conodont apatite show unexpectedly large variations (up to ~ 1‰), with ratios ranging from - 0.6‰ to 0.3‰. These reconnaissance data reveal a reasonable correlation between d88/86Sr and radiogenic87Sr/86Sr* (r2 = 0.60, n = 13, p = 0.002), suggesting that the controls from differential weathering regimes and/or continental crustal compositions buffered ancient seawater compositions. |
| first_indexed | 2025-11-14T10:46:17Z |
| format | Journal Article |
| id | curtin-20.500.11937-70982 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:46:17Z |
| publishDate | 2017 |
| publisher | Elsevier Science BV |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-709822023-08-02T06:39:12Z Conodont apatite d88/86Sr and d44/40Ca compositions and implications for the evolution of Palaeozoic to early Mesozoic seawater Le Houedec, S. McCulloch, M. Trotter, J. Rankenburg, Kai © 2017 Elsevier B.V. We present high precision (TIMS double spike) stable isotope measurements of both d44/40Ca and d88/86Sr together with radiogenic87Sr/86Sr ratios determined from conodont apatite. These data represent five intervals ranging from the early Ordovician to late Triassic. The conodont d44/40Ca values (relative to NIST 915a) range from - 0.47‰ to + 0.15‰, with an apparent shift to more positive values between the early Silurian and late Devonian/early Carboniferous, similar to the brachiopod-based marine d44/40Ca record (Farkaš et al., 2007a). We calculated a d44/40Ca seawater-bio-apatite fractionation factor of about - 1.9‰, which allowed us to reconstruct a palaeo-seawater d44/40Ca record from bio-apatites. Despite a slightly positive offset of about + 0.2 to + 0.5‰, the d44/40Ca record obtained from bio-apatites is consistent with the previously reported d44/40Ca seawater record inferred from carbonates. We find that unlike the carbonate d44/40Ca records, the d88/86Sr measurements from conodont apatite show unexpectedly large variations (up to ~ 1‰), with ratios ranging from - 0.6‰ to 0.3‰. These reconnaissance data reveal a reasonable correlation between d88/86Sr and radiogenic87Sr/86Sr* (r2 = 0.60, n = 13, p = 0.002), suggesting that the controls from differential weathering regimes and/or continental crustal compositions buffered ancient seawater compositions. 2017 Journal Article http://hdl.handle.net/20.500.11937/70982 10.1016/j.chemgeo.2017.02.013 Elsevier Science BV restricted |
| spellingShingle | Le Houedec, S. McCulloch, M. Trotter, J. Rankenburg, Kai Conodont apatite d88/86Sr and d44/40Ca compositions and implications for the evolution of Palaeozoic to early Mesozoic seawater |
| title | Conodont apatite d88/86Sr and d44/40Ca compositions and implications for the evolution of Palaeozoic to early Mesozoic seawater |
| title_full | Conodont apatite d88/86Sr and d44/40Ca compositions and implications for the evolution of Palaeozoic to early Mesozoic seawater |
| title_fullStr | Conodont apatite d88/86Sr and d44/40Ca compositions and implications for the evolution of Palaeozoic to early Mesozoic seawater |
| title_full_unstemmed | Conodont apatite d88/86Sr and d44/40Ca compositions and implications for the evolution of Palaeozoic to early Mesozoic seawater |
| title_short | Conodont apatite d88/86Sr and d44/40Ca compositions and implications for the evolution of Palaeozoic to early Mesozoic seawater |
| title_sort | conodont apatite d88/86sr and d44/40ca compositions and implications for the evolution of palaeozoic to early mesozoic seawater |
| url | http://hdl.handle.net/20.500.11937/70982 |