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Las relaciones isotópicas terrestres de carbono y nitrógeno de los nanodiamantes de la frontera entre el Cretácico y
Science (New York, N.Y.)
|December 4, 1992
Resumen
Los diamantes de tamaño nanométrico en el límite Cretácico-Terciario (K-T) no son interestelares. El análisis isotópico revela que son generados por el impacto, que difieren de los diamantes meteoríticos conocidos.
Área de la Ciencia:
- La geoquímica es la geoquímica.
- Cosmoquímica es la cosmoquímica.
- Ciencias planetarias Ciencias planetarias.
Sus antecedentes:
- Los diamantes de tamaño nanométrico se encuentran en el límite Cretácico-Terciario (K-T).
- Una hipótesis sugiere que estos diamantes son reliquias de granos interestelares del impacto de un asteroide.
Objetivo del estudio:
- Para investigar el origen de los diamantes de tamaño nanométrico en el límite K-T.
- Para determinar si estos diamantes son de origen interestelar o de impacto.
Principales métodos:
- Análisis de las relaciones isotópicas de carbono (13C/12C) y nitrógeno (15N/14N) en los diamantes límite K-T de América del Norte e Italia.
- Comparación de las firmas isotópicas con fuentes conocidas de diamantes meteoríticos y terrestres.
Principales resultados:
- Los diamantes de los yacimientos de América del Norte muestran mezclas de dos componentes con distintas composiciones isotópicas de carbono y nitrógeno y abundancias de nitrógeno.
- Los diamantes de un yacimiento italiano no muestran evidencia de estos componentes.
- Las firmas isotópicas de los diamantes K-T son distintas de los diamantes meteoríticos conocidos, incluidos los interestelares.
Conclusiones:
- Los nanodiamantes del límite K-T no son de origen interestelar.
- Los datos isotópicos sugieren fuertemente que los diamantes se formaron durante el evento de impacto de asteroides o su bola de fuego asociada.
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