Just out | Miocene flooding events of western Amazonia @ Science Advances

Just out @ Science Advances

Miocene flooding events of western Amazonia


Carlos Jaramillo, Ingrid Romero, Carlos D’Apolito, German Bayona, Edward Duarte, Stephen Louwye, Jaime Escobar, Javier Luque, Jorge D. Carrillo-Briceño, Vladimir Zapata, Alejandro Mora, Stefan Schouten, Michael Zavada, Guy Harrington, John Ortiz and Frank P. Wesselingh


There is a considerable controversy about whether western Amazonia was ever covered by marine waters during the Miocene [23 to 5 Ma (million years ago)]. We investigated the possible occurrence of Miocene marine incursions in the Llanos and Amazonas/Solimões basins, using sedimentological and palynological data from two sediment cores taken in eastern Colombia and northwestern Brazil together with seismic information. We observed two distinct marine intervals in the Llanos Basin, an early Miocene that lasted ~0.9 My (million years) (18.1 to 17.2 Ma) and a middle Miocene that lasted ~3.7 My (16.1 to 12.4 Ma). These two marine intervals are also seen in Amazonas/Solimões Basin (northwestern Amazonia) but were much shorter in duration, ~0.2 My (18.0 to 17.8 Ma) and ~0.4 My (14.1 to 13.7 Ma), respectively. Our results indicate that shallow marine waters covered the region at least twice during the Miocene, but the events were short-lived, rather than a continuous full-marine occupancy of Amazonian landscape over millions of years.

Keywords: amazonia, biodiversity, miocene, climate, biogeography, landscape

DOI: 10.1126/sciadv.1601693

READ IT HERE: http://advances.sciencemag.org/content/3/5/e1601693.full

(Image credit)

Lurdes Fonseca

Assistant Professor and Researcher at University of Lisbon
Sociologist (PhD), Paleontologist (Researcher in Micropaleontology), Majors in Sociology and Biology, Minor in Geology. Main interests in Paleontology: Microfossils, Molecular fossils, Paleobiology and Paleoecology. (read more about me)