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Geochemical evidence for a comet shower in the late Eocene

Science

By:
, , , and
DOI: 10.1126/science.280.5367.1250

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Abstract

Analyses of pelagic limestones indicate that the flux of extraterrestrial helium-3 to Earth was increased for a 2.5-million year (My) period in the late Eocene. The enhancement began ~1 My before and ended ~1.5 My after the major impact events that produced the large Popigai and Chesapeake Bay craters ~36 million years ago. The correlation between increased concentrations of helium-3, a tracer of fine-grained interplanetary dust, and large impacts indicates that the abundance of Earth-crossing objects and dustiness in the inner solar system were simultaneously but only briefly enhanced. These observations provide evidence for a comet shower triggered by an impulsive perturbation of the Oort cloud.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Geochemical evidence for a comet shower in the late Eocene
Series title:
Science
DOI:
10.1126/science.280.5367.1250
Volume
280
Issue:
5367
Year Published:
1998
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Science
First page:
1250
Last page:
1253
Number of Pages:
4