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Un bosque lluvioso tropical en Colorado 1,4 millones de años después de la frontera Cretácico-Terciario
1Department of Earth Sciences, Denver Museum of Nature & Science, Denver, CO 80205, USA. kjohnson@dmns.org
Science (New York, N.Y.)
|June 29, 2002
Resumen
Un diverso sitio de hojas fósiles del Paleoceno inferior en Colorado revela inesperadas selvas tropicales que prosperaron solo 1,4 millones de años después del evento de extinción del Cretácico-Terciario. Este hallazgo desafía las suposiciones anteriores sobre la recuperación de la flora después de la extinción.
Área de la Ciencia:
- La paleobotánica es la paleobotánica.
- Paleoclimatología Paleoclimatología
- Geología Geología Geología.
Sus antecedentes:
- El evento de extinción del Cretácico-Terciario (K-T) impactó significativamente la flora global, lo que condujo a comunidades de plantas del Paleoceno pobres en especies.
- La comprensión previa atribuía la baja diversidad de la flora del Paleoceno a las secuelas de la extinción K-T.
Objetivo del estudio:
- Para investigar un inusualmente diverso sitio de hojas fósiles del Paleoceno inferior descubierto en Castle Rock, Colorado.
- Para entender las condiciones ambientales que apoyaron un ecosistema de selva tropical de alta diversidad poco después de la frontera K-T.
Principales métodos:
- Análisis de la basura de hojas fósiles del sitio de Castle Rock.
- Comparación de la flora fósil con el bosque tropical ecuatorial existente. basura.
- Análisis del contexto geológico de la elevación de la Cuenca de Denver y la Cordillera Frontal de Laramide.
Principales resultados:
- El sitio de Castle Rock exhibe una gran diversidad de residuos fósiles, comparables a los bosques tropicales ecuatoriales modernos.
- Esta flora de alta diversidad existió hace aproximadamente 64,1 millones de años, dentro de 1,4 millones de años del límite K-T.
- El bosque tropical estaba situado en el margen de la cuenca de Denver dentro de rocas sedimentarias sinorogénicas.
Conclusiones:
- Las condiciones orográficas locales creadas por el Laramide Front Range, junto con un clima equilibrado, facilitaron el establecimiento de la selva tropical.
- Los hallazgos sugieren que los factores ambientales localizados, en lugar de la recuperación generalizada después de la extinción, permitieron los primeros bosques tropicales del Paleoceno en esta región.
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