McArthur, JM;
Millar, IL;
Drury, AJ;
Wagner, D;
(2025)
Strontium-isotope stratigraphy: methodology, standard values (SRM987, EN-1, E&A), a new Neogene curve of 87Sr/86Sr against time, its implications for astrochronology ([I]ODP Sites 1146, 1264, U1337, and U1338), and its application to ODP Site 758 (Indian summer monsoon) and IODP Site 1120 (a new age-model).
Palaeogeography, Palaeoclimatology, Palaeoecology
, 669
, Article 112907. 10.1016/j.palaeo.2025.112907.
Preview |
PDF
McArthur et al., 2025 - Neogene SIS, P3 2025.pdf - Published Version Download (4MB) | Preview |
Abstract
For the standards SRM(NIST) 987, EN-1, and E&A, we present compilations of 87Sr/86Sr from the literature, and 125 new measurements of 87Sr/86Sr, to arrive at recommend values of 0.710 248, 0.709 172, and 0.708 021 respectively, for normalising 87Sr/86Sr data for use in Sr-isotope stratigraphy. Using these standards, interlaboratory comparison of 87Sr/86Sr data is, nevertheless, impaired by residual bias of up to 0.000 072 that is not removed by normalisation of 87Sr/86Sr data to accepted values for standards. We also provide a new reference curve of 87Sr/86Sr against time for the period 11 to 20 Ma that is based on high-precision (± 0.000 003, 2 s.e.) analysis of 8 7Sr/86Sr in microfossil calcite from the ODP Sites 1146 and 1264, and IODP Sites U1337 and U1338. Ages for Site U1338 are calibrated by bio-magnetostratigraphy, whilst the others are calibrated by astrochronology, within which anomalies of up to 1.0 myrs are noted. With literature data, we extend the curve to 0 and 32 Ma. We show that the previous 87Sr/86Sr reference curve for the interval 0 – 7 Ma, that of Farrell et al. (1995) for Site 758 in the southern Bay of Bengal, is compromised by riverine influences from the Ganges/Brahmaputra rivers: differences between that curve and our new curve are interpreted to be a proxy for the intensity of the Indian summer monsoon. Finally, for Site 1120, a new age-model is presented, based on 87Sr/86Sr, in order to test the biostratigraphic age-model for the site, which is found to be good. This work shows that integrated approaches to improving the chronological framework of Cenozoic successions should include Sr-isotope stratigraphy.
| Type: | Article |
|---|---|
| Title: | Strontium-isotope stratigraphy: methodology, standard values (SRM987, EN-1, E&A), a new Neogene curve of 87Sr/86Sr against time, its implications for astrochronology ([I]ODP Sites 1146, 1264, U1337, and U1338), and its application to ODP Site 758 (Indian summer monsoon) and IODP Site 1120 (a new age-model) |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.palaeo.2025.112907 |
| Publisher version: | https://doi.org/10.1016/j.palaeo.2025.112907 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | EN-1, SRM987, E&A, SIS, Sr-isotope, 87Sr/86Sr, Neogene, Site 758, Site 1120, Site 1264, Site U1337, Site U1338, Indian summer monsoon |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10207433 |
Archive Staff Only
 |
View Item |
