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Composición isotópica de azufre del sulfato de agua de mar cenozoica
1A. Paytan, M. Kastner, and D. Campbell are in the Geosciences Research Division, Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093, USA. M. H. Thiemens is in the Chemistry Department, University of California, San Dieg.
Science (New York, N.Y.)
|November 20, 1998
Resumen
Este estudio presenta una curva de isótopos de sulfato de azufre del agua de mar del Cenozoico, que revela cambios significativos en millones de años. Los hallazgos sugieren que los ciclos de azufre y carbono no solo controlaban el oxígeno atmosférico en el Cenozoico.
Área de la Ciencia:
- La geoquímica es la geoquímica.
- La paleoceanografía es la paleoceanografía.
- Geoquímica de isótopos La geoquímica de isótopos es la química de los isótopos.
Sus antecedentes:
- Comprender el ciclo del azufre del Cenozoico es crucial para reconstruir las condiciones oceánicas pasadas y la composición atmosférica.
- La barita marina sirve como un valioso archivo para la composición isotópica del sulfato del agua de mar.
Objetivo del estudio:
- Para generar una curva de isótopos de azufre de alta resolución para el sulfato de agua de mar del Cenozoico.
- Investigar la relación entre los ciclos de azufre y carbono y su influencia en los niveles de oxígeno atmosférico.
Principales métodos:
- Análisis de muestras de barita marina para determinar las composiciones de isótopos de azufre.
- Comparación de la curva de isótopos de azufre generados con los registros de isótopos de carbono de carbonato marino existentes.
Principales resultados:
- Una detallada curva de isótopos de sulfato de azufre del agua de mar del Cenozoico (aprox. 1 millón de años de resolución) fue establecido.
- La curva muestra una disminución de 65-55 Ma, un aumento abrupto de 55-45 Ma, estabilidad de 35-2 Ma, y una disminución reciente.
- No se encontró un acoplamiento sistemático claro entre los ciclos de azufre y carbono durante millones de años.
Conclusiones:
- Los cambios en las tasas de enterramiento de pirita de azufre y carbono orgánico no solo dictaron el oxígeno atmosférico en cortas escalas de tiempo del Cenozoico.
- Estos hallazgos impactan los modelos de regulación del oxígeno atmosférico y la dinámica climática del Cenozoico.
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