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Characterization of Calcification Events Using Live Optical and Electron Microscopy Techniques in a Marine Tubeworm
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Un ciclo dinámico de calcio marino durante los últimos 28 millones de años
Elizabeth M Griffith1, Adina Paytan, Ken Caldeira
1Department of Geological and Environmental Sciences, Stanford University, Building 320, Room 118, Stanford, CA 94305, USA. egriffith@ucsc.edu
Science (New York, N.Y.)
|December 17, 2008
Resumen
Las proporciones de isótopos de calcio en el agua de mar revelan cambios significativos en los últimos 28 millones de años. Un cambio notable hace unos 13 millones de años indica la evolución de las concentraciones de calcio y una reorganización del sistema biogeoquímico global.
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:
- La composición y concentración de isótopos de calcio del agua de mar han variado durante los últimos 28 millones de años.
- Estudios previos indican cambios en las proporciones isotópicas de calcio marino.
Objetivo del estudio:
- Para reconstruir una curva de relación de isótopos de calcio de agua de mar continua y de alta resolución.
- Identificar características distintas en la evolución de los isótopos de calcio del agua de mar e inferir cambios en las concentraciones de calcio.
Principales métodos:
- Análisis de la barita marina (pelágica) para la composición isotópica de alta resolución.
- Desarrollo de una curva continua de la proporción de isótopos de calcio del agua de mar (delta44/40Ca).
Principales resultados:
- Se generó una curva distinta de la relación de isótopos de calcio del agua de mar, que muestra características evolutivas significativas.
- Un aumento pronunciado de 0,3 por mil en delta44/40Ca se produjo durante aproximadamente 4 millones de años después de un período de bajos valores hace unos 13 millones de años.
Conclusiones:
- Los cambios observados en las proporciones de isótopos marinos de calcio se correlacionan con una importante transición climática y cambios en el ciclo global del carbono.
- Estos hallazgos sugieren una reorganización del sistema biogeoquímico global impulsada por cambios en el calcio del agua de mar.
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