A short duration of the Cretaceous-Tertiary boundary event: Evidence from extraterrestrial helium-3
A short duration of the Cretaceous-Tertiary boundary event: Evidence from extraterrestrial helium-3
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DOI：
10.1126/science.291.5510.1952
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发表时间：
2001-03-09
期刊：
影响因子：
56.9
通讯作者：
Montanari, A
中科院分区：
文献类型：
--
作者：
Mukhopadhyay, S;Farley, KA;Montanari, A
对6390万至6540万年前的海洋碳酸盐的分析表明，地外氦-3的通量几乎是恒定的，这是行星际尘埃向地球吸积速率的示踪剂。这一观测结果表明，与第三纪灭绝事件（K-T）相关的火流星并没有伴随着太阳系尘埃的增加，因此不可能是彗星雨的成员。使用氦-3作为沉积速率的恒定通量代用指标意味着K-T边界粘土在（10 +/- 2）x 10（3）年内沉积，排除了边界长间断的可能性，并需要极快速的动物群更替。
Analyses of marine carbonates through the interval 63.9 to 65.4 million years ago indicate a near-constant flux of extraterrestrial helium-3, a tracer of the accretion rate of interplanetary dust to Earth. This observation indicates that the bolide associated with the Cretaceous-Tertiary (K-T) extinction event was not accompanied by enhanced solar system dustiness and so could not have been a member of a comet shower. The use of helium-3 as a constant-flux proxy of sedimentation rate implies deposition of the K-T boundary clay in (10 +/- 2) x 10(3) years, precluding the possibility of a Long hiatus at the boundary and requiring extremely rapid faunal turnover.