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The Eocene/Oligocene boundary event in the deep sea.
Science (New York, N.Y.)
|November 16, 1984
Summary
The Eocene/Oligocene boundary shows gradual microfossil changes, not a mass extinction. Paleoclimate shifts, not a bolide impact, drove late Paleogene biotic changes.
Area of Science:
- Paleontology
- Micropaleontology
- Paleoceanography
Background:
- The Eocene/Oligocene boundary is a critical interval in Earth's history.
- Previous hypotheses suggested a catastrophic event, possibly a bolide impact, at this boundary.
Purpose of the Study:
- To analyze biotic changes across the Eocene/Oligocene boundary.
- To investigate the causes of biotic changes during the late Paleogene.
Main Methods:
- Analysis of calcareous microfossils.
- Analysis of siliceous microfossils.
Main Results:
- Observed gradual biotic changes, with no evidence of a massive extinction event.
- Identified biotic shifts correlating with changing paleoclimatic and paleoceanographic conditions.
- Found no support for a bolide impact event causing a catastrophic biotic event.
Conclusions:
- Biotic changes across the Eocene/Oligocene boundary were gradual and driven by environmental shifts.
- The late Paleogene experienced significant paleoceanographic and paleoclimatic changes impacting marine life.
- The data refutes the hypothesis of a bolide impact-induced mass extinction at the Eocene/Oligocene boundary.
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