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Composiciones isotópicas y orígenes probables de las moléculas orgánicas en el esquisto Messel del Eoceno
J M Hayes1, R Takigiku, R Ocampo
1Department of Chemistry, Indiana University, Bloomington 47405-5101, USA.
Nature
|September 3, 1987
Resumen
El esquisto de Messel es un esquisto de Messel.
Área de la Ciencia:
- La geoquímica es la geoquímica.
- La paleolimnología.
- La geoquímica orgánica es la geoquímica orgánica.
Sus antecedentes:
- Los sedimentos de esquisto de Messel se formaron hace 47 millones de años en un lago con condiciones anaerobias.
- Se observa una excelente conservación de la materia orgánica (hasta un 25% de carbono orgánico).
- Las geoporfirinas indican una zona fótica anaeróbica en el antiguo lago.
Objetivo del estudio:
- Identificar las fuentes de materia orgánica y reconstruir el flujo de carbono en el ecosistema del lago Messel.
- Para utilizar las composiciones isotópicas de carbono de los biomarcadores para la reconstrucción paleoambiental.
Principales métodos:
- Aislamiento e identificación de 16 geoporfirinas diferentes.
- Análisis de las composiciones isotópicas de carbono (13C) de las geoporfirinas y otros biomarcadores.
- Estimación del contenido de 13C de los productores primarios basado en derivados de la clorofila.
Principales resultados:
- Fuentes específicas de materia orgánica identificadas y vías de flujo de carbono reconstruidas.
- Estimó el contenido de 13C de los productores primarios lacustres.
- Se observó un agotamiento de 13C de seis partes por mil en la materia orgánica total en comparación con los insumos de los productores primarios.
Conclusiones:
- El agotamiento del 13C no se explica por la pérdida selectiva de compuestos enriquecidos con 13C.
- Los insumos de las plantas terrestres circundantes o las bacterias metanogénicas no explican el agotamiento observado del 13C.
- El estudio proporciona información sobre el ciclo del carbono en antiguos entornos lacustres.
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