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Comentario a "Apatita 4He/3He y (U-Th) /He evidencia de un antiguo Gran Cañón"
Karl E Karlstrom1, John Lee, Shari Kelley
1University of New Mexico, Albuquerque, NM 87131, USA. kek1@unm.edu
Science (New York, N.Y.)
|April 17, 2013
Resumen
El Gran Cañón es el Gran Cañón.
Área de la Ciencia:
- Geología Geología Geología.
- Ciencias de la Tierra Ciencias de la Tierra Ciencias de la Tierra
- Geomorfología Geomorfología.
Sus antecedentes:
- Existen modelos de edad contrastantes para el Gran Cañón: 70 millones de años frente a 6 millones de años.
- Investigaciones anteriores proponían paleocaniones a 70 Ma y 55 Ma.
Objetivo del estudio:
- Para conciliar los modelos de edad conflictivos para el Gran Cañón.
- Proponer una línea de tiempo revisada para la formación del Gran Cañón.
Principales métodos:
- Análisis de los modelos de refrigeración.
- Evaluación de datos geológicos.
Principales resultados:
- Un paleocanyon poco profundo existía en el este del Gran Cañón hace 25 a 15 millones de años (Ma).
- Este hallazgo niega las propuestas anteriores de paleocaniones de 70 Ma y 55 Ma.
- Los modelos de enfriamiento y los datos geológicos apoyan una edad de 5 a 6 Ma para el oeste del Gran Cañón y el Cañón de Mármol.
Conclusiones:
- La formación del Gran Cañón se explica mejor por una combinación de un paleocanión oriental más antiguo y un cañón occidental más joven.
- El Gran Cañón occidental y el Cañón de Mármol probablemente se formaron hace entre 5 y 6 millones de años.
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