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Una perspectiva de isótopos de litio en la evolución de los ciclos de carbono y silicio
Boriana Kalderon-Asael1, Joachim A R Katchinoff2, Noah J Planavsky3
1Earth and Planetary Sciences, Yale University, New Haven, CT, USA. boriana.kalderon-asael@yale.edu.
Nature
|July 15, 2021
Resumen
El registro de isótopos de litio revela cambios a largo plazo en los ciclos de carbono y silicio de la Tierra, lo que indica un cambio desde el Precámbrico a los procesos modernos. Esta evolución está relacionada con los controles biológicos del silicio y el aumento de las plantas terrestres.
Área de la Ciencia:
- Geoquímica
- Paleoclimatología
- Ciencias de la Tierra
Sus antecedentes:
- Los ciclos globales de carbono y silicio influyen en la estabilidad climática a largo plazo de la Tierra.
- Los mecanismos de retroalimentación y las restricciones cuantitativas de estos ciclos siguen siendo poco conocidos.
- El registro de isótopos de litio ofrece un nuevo sustituto para rastrear estos ciclos elementales.
Objetivo del estudio:
- Para utilizar el registro de isótopos de litio para investigar la evolución del ciclo de carbono y silicio a largo plazo.
- Para establecer un registro completo de isótopos de litio basados en carbonato que abarca los últimos 3 mil millones de años.
- Comprender las causas de las tendencias observadas en los valores de isótopos de litio.
Principales métodos:
- Análisis de más de 600 muestras de carbonato marino de aguas poco profundas de diversas unidades estratigráficas.
- Construcción de un registro de isótopos de litio basado en carbonato de 3 mil millones de años.
- Modelado de equilibrio de masas para interpretar las tendencias isotópicas.
Principales resultados:
- Se identificó un aumento significativo de los valores de isótopos de litio en el tiempo geológico.
- Esta tendencia se atribuye a la evolución de las condiciones isotópicas de litio en el agua de mar.
- Los datos sugieren una transición desde el Precámbrico al ciclo moderno de carbono y silicio.
Conclusiones:
- El registro de isótopos de litio proporciona información crucial sobre la evolución de los ciclos de carbono y silicio de la Tierra.
- Las tendencias observadas reflejan un cambio fundamental en estos ciclos biogeoquímicos.
- Esta transición puede estar relacionada con el surgimiento del ciclo de silicio mediado biológicamente y la vida vegetal terrestre.
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