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Published on: July 1, 2019
La evidencia del isótopo de neodimio para una composición condrítica de la Luna
K Rankenburg1, A D Brandon, C R Neal
1NASA Johnson Space Center, Mail Code KR, Houston, TX 77058, USA. kai.rankenburg1@jsc.nasa.gov
Resumen
La Luna La Luna es la Luna.
Área de la Ciencia:
- La geoquímica es la geoquímica.
- Cosmoquímica es la cosmoquímica.
- Geología de Isótopos Geología de Isótopos.
Sus antecedentes:
- La Tierra y la Luna probablemente se formaron en la misma región de la nebulosa solar.
- Comprender la composición isotópica de la Luna proporciona información sobre la formación y evolución de los planetas.
- El sistema de isótopos Samario-Neodimio (Sm/Nd) es una poderosa herramienta para la datación de la diferenciación planetaria.
Objetivo del estudio:
- Para determinar la composición isotópica de samario-neodimio (Sm/Nd) de la mayor parte de la Luna.
- Para restringir la edad de formación del manto lunar.
- Investigar las implicaciones para la diferenciación temprana de la Tierra y la Luna.
Principales métodos:
- Análisis de las proporciones de isótopos de samario-neodimio (Sm/Nd) en seis muestras de basalto lunar.
- Cálculo de la relación 142Nd/144Nd para el bulto de la Luna.
- Modelado del intervalo de formación del manto lunar.
Principales resultados:
- El bulto de la Luna exhibe una proporción de 142Nd/144Nd indistinguible de los meteoritos condríticos.
- El manto lunar se formó 215(-21)(+23) millones de años después del inicio de la condensación del sistema solar.
- La relación 142Nd/144Nd de la Luna es aproximadamente 20 partes por millón más baja que la mayoría de las muestras terrestres.
Conclusiones:
- La Tierra y la Luna probablemente comparten un origen condrítico común.
- Un depósito complementario con un valor más bajo de 142Nd/144Nd debe existir dentro del manto de la Tierra para equilibrar el presupuesto de neodimio.
- Estos hallazgos tienen implicaciones significativas para los modelos de diferenciación planetaria temprana y la evolución isotópica de los planetas terrestres.
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