Revised onset age of magnetochron M0r: Chronostratigraphic and geologic implications
| العنوان: | Revised onset age of magnetochron M0r: Chronostratigraphic and geologic implications |
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| المؤلفون: | Youjuan Li, Huafeng Qin, Brian R. Jicha, Magdalena H. Huyskens, Corey J. Wall, Robin B. Trayler, Qing-Zhu Yin, Mark Schmitz, Yongxin Pan, Chenglong Deng, Brad S. Singer, Huaiyu He, Rixiang Zhu |
| المصدر: | Geology. 51:565-570 |
| بيانات النشر: | Geological Society of America, 2023. |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Geology |
| الوصف: | The timing of the onset of magnetochron M0r and its duration are disputed, reflecting both a limited set of radioisotopic dates and uncertain magnetostratigraphic correlations. We present a chronostratigraphic framework for a reversed polarity interval based on two chronometers (40Ar/39Ar, U-Pb) and newly published paleomagnetic data from the Qingshan Group, Jiaolai Basin, China. Bayesian modeling of U-Pb zircon and 40Ar/39Ar sanidine dates suggests a minimum duration of 540 ± 37 k.y. (95% credible interval) for the reversed polarity interval. These findings are compatible with an astrochronologic age model for M-sequence seafloor magnetic anomalies, indicating that the reversely magnetized sediments correspond to magnetochron M0r rather than the shorter chron “M-1r.” Integration of U-Pb and 40Ar/39Ar ages constrains the onset of M0r to 120.29 ± 0.09 Ma, which is ~1 m.y. younger than that inferred in the current geologic time scale (GTS 2020). This finding also implies that the Cretaceous normal superchron (CNS) began at 119.70 ± 0.12 Ma and that the average seafloor spreading rate during the CNS was ~3.5% higher than that inferred from GTS 2020. It also suggests that oceanic anoxic event 1a began at 119.40 ± 0.12 Ma, thereby providing an updated chronologic basis for exploring the primary trigger of this carbon cycle perturbation. |
| تدمد: | 1943-2682 0091-7613 |
| DOI: | 10.1130/g50873.1 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::41b04ff2884214a36da67fe99494fabc https://doi.org/10.1130/g50873.1 |
| رقم الانضمام: | edsair.doi...........41b04ff2884214a36da67fe99494fabc |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 19432682 00917613 |
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| DOI: | 10.1130/g50873.1 |