Fossil pollen records indicate that Patagonian desertification was not solely a consequence of Andean uplift
The Patagonian steppe—a massive rain-shadow on the lee side of the southern Andes—is assumed to have evolved ~15–12 Myr as a consequence of the southern Andean uplift. However, fossil evidence supporting this assumption is limited. Here we quantitatively estimate climatic conditions and plant richne...
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| Autores principales: | , , , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
2014
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| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/95476 https://ri.conicet.gov.ar/11336/7533 http://www.nature.com/articles/ncomms4558 |
| Aporte de: |
| Sumario: | The Patagonian steppe—a massive rain-shadow on the lee side of the southern Andes—is assumed to have evolved ~15–12 Myr as a consequence of the southern Andean uplift. However, fossil evidence supporting this assumption is limited. Here we quantitatively estimate climatic conditions and plant richness for the interval ~10–6 Myr based on the study and bioclimatic analysis of terrestrially derived spore–pollen assemblages preserved in well-constrained Patagonian marine deposits. Our analyses indicate a mesothermal climate, with mean temperatures of the coldest quarter between 11.4 °C and 16.9 °C (presently ~3.5 °C) and annual precipitation rarely below 661 mm (presently ~200 mm). Rarefied richness reveals a significantly more diverse flora during the late Miocene than today at the same latitude but comparable with that approximately 2,000 km further northeast at mid-latitudes on the Brazilian coast. We infer that the Patagonian desertification was not solely a consequence of the Andean uplift as previously insinuated. |
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