On the viability of detrital biotite Rb–Sr geochronology
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Published:2024-07-02
Issue:3
Volume:6
Page:303-312
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ISSN:2628-3719
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Container-title:Geochronology
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language:en
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Short-container-title:Geochronology
Author:
Larson Kyle P.ORCID, Dyck Brendan, Shrestha Sudip, Button Mark, Najman Yani
Abstract
Abstract. Re-examination of International Ocean Discovery Program (IODP) sediment samples collected from the Bay of Bengal via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) Rb–Sr geochronology demonstrates the viability of the biotite Rb–Sr system for use as a detrital chronometer. The age population defined by the Rb–Sr dates essentially reproduces that previously published for detrital 40Ar/39Ar dates. The effect of unknown/assumed initial 87Sr/86Sr on the calculated population can be ameliorated by filtering for higher 87Rb/86Sr ratios. Such filtering, however, could introduce bias toward more radiogenic populations, especially in younger material that has not had time to accumulate radiogenic product (e.g. limiting the effect of initial 87Sr/86Sr to ∼ <5 % requires filtering of 87Rb/86Sr
>500 at 250 Ma and 87Rb/86Sr >50 at 2500 Ma). Finally, Ti-in-biotite temperatures calculated based on element concentration data collected during LA-ICP-MS overlap with those calculated for the same material based on electron probe microanalyzer data, demonstrating the potential for in situ biotite petrochronology based on the Rb–Sr system.
Funder
Natural Sciences and Engineering Research Council of Canada
Publisher
Copernicus GmbH
Reference53 articles.
1. Armstrong, R. L., Jäger, E., and Eberhardt, P.: A comparison of K-Ar and Rb-Sr ages on Alpine biotites, Earth Planet. Sc. Lett., 1, 13–19, 1966. 2. Camacho, A., Lee, J. K. W., Fitz Gerald, J. D., Zhao, J., Abdu, Y. A., Jenkins, D. M., Hawthorne, F. C., Kyser, T. K., Creaser, R. A., Armstrong, R., and Heaman, L. W.: Planar defects as Ar traps in trioctahedral micas: A mechanism for increased Ar retentivity in phlogopite, Earth Planet. Sc. Lett., 341–344, 255–267, 2012. 3. Camacho, A., Lee, J. K. W., Zhao, J., Abdu, Y. A., Fayek, M., and Creaser, R. A.: A test of the interlayer ionic porosity model as a measure of argon diffusivity in trioctahedral micas, Geochim. Cosmochim. Ac., 288, 341–368, 2020. 4. Crossingham, T., Sobczak, K., La Croix, A. D., Esterle, J., Dalton, H., and Hayes, P.: Detrital or reset? 40Ar/39Ar dating of mica from the Lower Jurassic Precipice Sandstone and Evergreen Formation in the Surat Basin, Aust. J. Earth Sci., 71, 585–599, https://doi.org/10.1080/08120099.2024.2319105, 2024. 5. Del Moro, A., Puxeddu, M., di Brozolo, F. R., and Villa, I. M.: Rb-Sr and K-Ar ages on minerals at temperatures of 300°–400° C from deep wells in the Larderello geothermal field (Italy), Contrib. Mineral. Petrol., 81, 340–349, 1982.
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