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Evidencia para el control glacial de los rápidos cambios en el nivel del mar en el Cretácico temprano
1Department of Geological and Geophysical Sciences, Princeton University, Princeton, NJ 08544-1003, USA.
Science (New York, N.Y.)
|June 21, 1996
Resumen
Los picos repentinos de estroncio en los sedimentos del Cretácico Inferior sugieren rápidos cambios en el nivel del mar. Los isótopos de oxígeno indican que el crecimiento de la capa de hielo continental, potencialmente incluyendo una capa de hielo antártica, impulsó estas fluctuaciones.
Área de la Ciencia:
- La geoquímica es la geoquímica.
- La paleoceanografía es la paleoceanografía.
- Ciencias del clima Ciencias del clima Ciencias del clima Ciencias del clima
Sus antecedentes:
- Los sedimentos de aguas profundas del Cretácico Inferior contienen estroncio, lo que indica cambios en la exposición de la plataforma continental.
- Las fluctuaciones globales del nivel del mar son un área clave de la investigación paleoclimática.
Objetivo del estudio:
- Para investigar las causas de los rápidos cambios en el nivel del mar durante el Cretácico Temprano.
- Para correlacionar los datos de los isótopos de estroncio y oxígeno con los modelos existentes del nivel del mar.
Principales métodos:
- Análisis de las concentraciones masivas de carbonato de estroncio en sedimentos de aguas profundas.
- Medidas de isótopos de oxígeno de fósiles marinos.
Principales resultados:
- Los datos del estroncio revelan fluctuaciones globales del nivel del mar de aproximadamente 50 metros en escalas de tiempo de 200.000-500.000 años.
- Los datos de isótopos de oxígeno sugieren que estas fluctuaciones fueron impulsadas por el crecimiento y la desintegración de las capas de hielo continentales.
- Los hallazgos se alinean con la curva del nivel del mar de Exxon, lo que implica eventos de glaciación significativos.
Conclusiones:
- Los rápidos cambios en el nivel del mar en el Cretácico Temprano fueron causados principalmente por la glaciación.
- La existencia de una capa de hielo antártica es plausible, incluso durante períodos de calentamiento global general.
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