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Fluctuaciones de isótopos de azufre en el agua de mar en el Cretácico
Adina Paytan1, Miriam Kastner, Douglas Campbell
1Department of Geological and Environmental Sciences, Stanford University, Stanford CA 94305-2115, USA. apaytan@pangea.stanford.edu
Science (New York, N.Y.)
|June 12, 2004
Resumen
El ciclo del azufre del Cretácico muestra isótopos de azufre más ligeros, posiblemente de la actividad volcánica. Los cambios en los isótopos de azufre sugieren cambios en el enterramiento de carbono orgánico y los niveles de oxígeno atmosférico.
Área de la Ciencia:
- Ciencias de la Tierra Ciencias de la Tierra Ciencias de la Tierra
- Biogeoquímica La biogeoquímica es la bioquímica.
- Paleoclimatología Paleoclimatología
Sus antecedentes:
- El ciclo de azufre exogénico es parte integral de la biogeoquímica de la Tierra, estrechamente vinculado con los ciclos de carbono y oxígeno.
- La comprensión de los ciclos de azufre pasados proporciona información sobre la dinámica ambiental global.
Objetivo del estudio:
- Presentar un registro de alta resolución de la composición isotópica de azufre del sulfato del agua de mar durante el período Cretácico.
- Investigar los impulsores e implicaciones de las variaciones del ciclo del azufre en el Cretácico.
Principales métodos:
- Análisis de la composición isotópica del azufre en el sulfato de agua de mar.
- Reconstrucción de registro geoquímico de alta resolución.
Principales resultados:
- Un enriquecimiento general de azufre isotópicamente ligero durante el Cretácico, potencialmente relacionado con el aumento de la actividad volcánica e hidrotermal.
- Dos excursiones distintas hacia isótopos de azufre más ligeros indican tasas reducidas de enterramiento de pirita.
- Los cambios simultáneos en los isótopos de azufre y carbono inorgánico sugieren fluctuaciones a corto plazo del oxígeno atmosférico.
Conclusiones:
- Las variaciones del ciclo del azufre del Cretácico fueron influenciadas por la actividad volcánica y los cambios en los lugares de enterramiento de carbono orgánico.
- Las fluctuaciones en los isótopos de sulfato del agua de mar proporcionan evidencia de cambios dinámicos en los sistemas biogeoquímicos de la Tierra y la composición atmosférica.
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