Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1073/pnas.2020977118 |
Asteroid break-ups and meteorite delivery to Earth the past 500 million years | |
Fredrik Terfelt; Birger Schmitz | |
2021-06-15 | |
发表期刊 | Proceedings of the National Academy of Science
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出版年 | 2021 |
英文摘要 | The meteoritic material falling on Earth is believed to derive from large break-up or cratering events in the asteroid belt. The flux of extraterrestrial material would then vary in accordance with the timing of such asteroid family-forming events. In order to validate this, we investigated marine sediments representing 15 time-windows in the Phanerozoic for content of micrometeoritic relict chrome-spinel grains (>32 μm). We compare these data with the timing of the 15 largest break-up events involving chrome-spinel–bearing asteroids (S- and V-types). Unexpectedly, our Phanerozoic time windows show a stable flux dominated by ordinary chondrites similar to today’s flux. Only in the mid-Ordovician, in connection with the break-up of the L-chondrite parent body, do we observe an anomalous micrometeorite regime with a two to three orders-of-magnitude increase in the flux of L-chondritic chrome-spinel grains to Earth. This corresponds to a one order-of-magnitude excess in the number of impact craters in the mid-Ordovician following the L-chondrite break-up, the only resolvable peak in Phanerozoic cratering rates indicative of an asteroid shower. We argue that meteorites and small (<1-km-sized) asteroids impacting Earth mainly sample a very small region of orbital space in the asteroid belt. This selectiveness has been remarkably stable over the past 500 Ma. |
领域 | 地球科学 |
URL | 查看原文 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/329829 |
专题 | 地球科学 |
推荐引用方式 GB/T 7714 | Fredrik Terfelt,Birger Schmitz. Asteroid break-ups and meteorite delivery to Earth the past 500 million years[J]. Proceedings of the National Academy of Science,2021. |
APA | Fredrik Terfelt,&Birger Schmitz.(2021).Asteroid break-ups and meteorite delivery to Earth the past 500 million years.Proceedings of the National Academy of Science. |
MLA | Fredrik Terfelt,et al."Asteroid break-ups and meteorite delivery to Earth the past 500 million years".Proceedings of the National Academy of Science (2021). |
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