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Atom Probe Tomography Analysis of Exsolved Mineral Phases
Published on: October 25, 2019
Extenso vulcanismo asociado con la separación de Australia y la Antártida
Science (New York, N.Y.)
|October 19, 1984
Resumen
La ceniza volcánica del Eoceno tardío se alteró en ópalo-CT en Australia del Sur, reflejando los depósitos globales. Esto indica una amplia actividad volcánica al sur de Australia durante ese período.
Área de la Ciencia:
- Geología Geología Geología.
- Paleontología Paleontología.
- Volcanología Volcanología.
Sus antecedentes:
- La Formación Blanche Point en Australia del Sur contiene capas duras y blandas que se alternan.
- Estas capas están compuestas de ceniza volcánica, espículas de esponja y restos fósiles.
- La silicificación selectiva más tarde formó las capas duras.
Objetivo del estudio:
- Para analizar la composición y el origen de la Formación Blanche Point.
- Para comparar estos depósitos del sur de Australia con formaciones geológicas similares a nivel mundial.
- Para inferir el alcance y la causa de la actividad volcánica del Eoceno tardío.
Principales métodos:
- Análisis sedimentario de las rocas Gull Rock y Tuit Members.
- Investigación geoquímica de los procesos de alteración de minerales.
- Estratigrafía comparativa con depósitos del Cretácico y el Eoceno.
Principales resultados:
- La alteración de la ceniza volcánica produjo smectita y clinoptilolita, liberando sílice.
- La sílice se cristalizó como ópalo-CT, formando las capas duras.
- Se han encontrado depósitos similares desde Nueva Zelanda hasta Australia Occidental.
Conclusiones:
- El proceso de alteración es consistente en todas las ubicaciones geográficamente diversas.
- Extensa actividad volcánica del Eoceno tardío se produjo al sur de Australia.
- Este vulcanismo está vinculado a la ruptura y separación de la Antártida.
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