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Evidencia de un gran impacto de meteorito en la Tierra hace 34 millones de años: implicación para las extinciones del
Science (New York, N.Y.)
|May 21, 1982
Resumen
Un impacto masivo de meteorito hace 34 millones de años probablemente causó extinciones, como lo demuestran los sedimentos ricos en iridio y las microtektitas encontradas en un núcleo de aguas profundas del Caribe.
Área de la Ciencia:
- Geología Geología Geología.
- Paleontología Paleontología.
- Ciencias planetarias Ciencias planetarias.
Sus antecedentes:
- Los núcleos de sedimentos de aguas profundas proporcionan archivos invaluables de la historia de la Tierra.
- El período Paleógeno experimentó eventos geológicos y biológicos significativos.
- Los escombros meteoríticos se pueden utilizar para datar eventos geológicos e identificar cráteres de impacto.
Objetivo del estudio:
- Para investigar la causa de un evento de extinción masiva hace aproximadamente 34 millones de años.
- Para analizar la composición de una capa de sedimento única en un núcleo de aguas profundas del Caribe.
- Para correlacionar los hallazgos geológicos con las extinciones biológicas.
Principales métodos:
- Análisis del núcleo del sedimento.
- Análisis geoquímico para el enriquecimiento de iridio.
- Identificación y datación de la microtektita.
- Análisis de fósiles radiolarios para patrones de extinción.
Principales resultados:
- Se identificó una capa de sedimento distinta altamente enriquecida en iridio meteorítico.
- Esta capa de iridio se encontró debajo de microtektitas norteamericanas fechadas hace 34,4 millones de años.
- La capa de iridio coincidió con la extinción de cinco especies principales de Radiolaria.
Conclusiones:
- Los hallazgos sugieren que un impacto masivo de meteorito ocurrió hace unos 34 millones de años.
- El evento de impacto probablemente produjo las microtektitas observadas y la anomalía de iridio.
- Este impacto se propone como la causa de las extinciones masivas observadas en Radiolaria.
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