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El grosor de la corteza en la cordillera del Atlántico medio: anomalías de la gravedad de ojo de toro y acreción
Science (New York, N.Y.)
|October 29, 1993
Resumen
Los segmentos de extensión de la cresta del Atlántico Medio exhiben anomalías de gravedad negativa debido a las variaciones en el grosor de la corteza. Una corteza más gruesa en los centros de los segmentos y una corteza más delgada en los extremos, impulsada por las variaciones de la capa 3, explica estos hallazgos.
Área de la Ciencia:
- La geofísica es la geofísica.
- Geología marina Geología marina.
- La tectónica de placas es la tectónica de placas.
Sus antecedentes:
- Los segmentos que se extienden de la cresta del Atlántico medio se caracterizan por anomalías negativas del ojo de toro en el campo de gravedad del manto Bouguer.
- Comprender la fuente de estas anomalías gravitacionales es crucial para interpretar la estructura de la corteza y los procesos de acreción en las cordilleras oceánicas medias.
Objetivo del estudio:
- Para investigar la causa de las anomalías gravitatorias negativas del ojo de toros a lo largo de un segmento de la cresta del Atlántico Medio.
- Determinar la relación entre las variaciones de espesor de la corteza terrestre y las anomalías de la gravedad utilizando datos de refracción sísmica.
Principales métodos:
- Adquisición y análisis de datos de refracción sísmica a 33 grados S en la cresta del Atlántico Medio.
- Modelado de anomalías gravitatorias basadas en variaciones en el grosor de la corteza y en la capa 3.
Principales resultados:
- Las anomalías negativas de la gravedad del ojo de toros se explican por las variaciones en el grosor de la corteza a lo largo del segmento de propagación.
- El grosor de la corteza es mayor en el centro del segmento y disminuye hacia los extremos del segmento.
- Estas variaciones de grosor se atribuyen principalmente a cambios en el grosor de la capa 3.
Conclusiones:
- La acreción de la corteza se centra en este segmento de cresta de expansión lenta.
- La profundidad del valle axial está directamente relacionada con el grosor de la corteza subyacente.
- Las variaciones de densidad a lo largo del eje deben considerarse al interpretar los datos de gravedad de las crestas oceánicas medias.
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