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La glaciación criogénica y el inicio del desacoplamiento de isótopos de carbono
Nicholas L Swanson-Hysell1, Catherine V Rose, Claire C Calmet
1Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.
Science (New York, N.Y.)
|May 1, 2010
Resumen
Los cambios globales en el ciclo del carbono están vinculados a la historia de la Tierra. Nuevos datos de isótopos de carbono revelan la disociación entre el carbonato y la materia orgánica durante el período criogénico, lo que sugiere cambios en las condiciones del océano.
Área de la Ciencia:
- La geociencia es la ciencia de la tierra.
- Paleoclimatología Paleoclimatología
- Biogeoquímica La biogeoquímica es la bioquímica.
Sus antecedentes:
- Las perturbaciones del ciclo global del carbono están vinculadas a la paleogeografía, la glaciación y la oxigenación del océano.
- Una notable excursión de isótopos de carbono de carbonato del Período Ediacárico fue explicada previamente por una gran reserva oceánica de carbono orgánico.
Objetivo del estudio:
- Para investigar el desacoplamiento de isótopos de carbono durante el período criogénico.
- Para probar modelos de crecimiento de la piscina de carbono orgánico y su relación con la química del océano.
Principales métodos:
- Análisis de datos de isótopos de carbono de carbonato y materia orgánica.
- Reconstrucción de la química del océano y las condiciones de flujo de los ríos.
Principales resultados:
- No se observó desacoplamiento de isótopos de carbono desde hace aproximadamente 820 a 760 millones de años.
- El desacoplamiento completo de los isótopos de carbono se produjo entre los eventos glaciales de Sturtian y Marinoan (período criogénico).
- El crecimiento de la piscina de carbono orgánico puede estar relacionado con las condiciones oceánicas profundas ricas en hierro y pobres en sulfatos.
Conclusiones:
- Los hallazgos desafían los modelos anteriores para las excursiones de isótopos de carbono de Ediacaran.
- La química oceánica, particularmente la relación Fe:S, jugó un papel crucial en la regulación de la piscina de carbono orgánico durante el período criogénico.
- Los eventos glaciales impactaron significativamente las condiciones del océano y el ciclo global del carbono.
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