Osmium isotope evidence for a large Late Triassic impact event
書誌事項
- 公開日
- 2013-09-16
- 資源種別
- journal article
- 権利情報
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- http://creativecommons.org/licenses/by-nc-sa/3.0
- DOI
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- 10.1038/ncomms3455
- 公開者
- Springer Science and Business Media LLC
説明
Anomalously high platinum group element concentrations have previously been reported for Upper Triassic deep-sea sediments, which are interpreted to be derived from an extraterrestrial impact event. Here we report the osmium (Os) isotope fingerprint of an extraterrestrial impact from Upper Triassic chert successions in Japan. Os isotope data exhibit a marked negative excursion from an initial Os isotope ratio ((187)Os/(188)Osi) of ~0.477 to unradiogenic values of ~0.126 in a platinum group element-enriched claystone layer, indicating the input of meteorite-derived Os into the sediments. The timing of the Os isotope excursion coincides with both elevated Os concentrations and low Re/Os ratios. The magnitude of this negative Os isotope excursion is comparable to those found at Cretaceous-Paleogene boundary sites. These geochemical lines of evidence demonstrate that a large impactor (3.3-7.8 km in diameter) produced a global decrease in seawater (187)Os/(188)Os ratios in the Late Triassic.
収録刊行物
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- Nature Communications
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Nature Communications 4 (1), 2455-, 2013-09-16
Springer Science and Business Media LLC
