Research Finds Closure of Panama Seaway Occurred 10 Million Years Earlier Than Previously Thought
Discovery Challenges Paradigms of Modern Climate and Biologic Evolution
The closure of the Panama Seaway has long been considered to have occurred 3 million years ago; however, recent research suggests the final closure took place 15 to 13 million years ago.
Juan Carlos Silva-Tamayo, assistant professor of sedimentology and environmental geology at University of Houston’s Department of Earth and Atmospheric Sciences, participated in research that focused on the precise timing of the interaction between Central and South America and on the closure of the Panama Seaway. Results from this research published in the April 10 issue of Science magazine. The article is titled “Middle Miocene Closure of the Central American Seaway.”
The closure of the Panama Seaway, which separated the Pacific Ocean from the Atlantic Ocean, is associated with one of the biggest biological exchanges in Earth history, i.e., the Great American Biological Interchange. The closure of the Panama Seaway during the Late Pliocene is also considered to have triggered the expansion of northern hemisphere glaciers and to have been one of the major mechanisms leading to the onset of the modern climate.
“Timing of the closure of the Panama Seaway has been a topic of great debate among the scientific community,” Silva-Tamayo said. “Determining the precise timing of the closure is vital for understanding the establishment of the modern climate and the evolutionary pathways of modern Inter-Americas biodiversity.”
The hypothesis of an early collision between Central and South America, leading to an earlier closure of the Panama Seaway, goes back to 2008 when Silva-Tamayo (see below, Silva-Tamayo et al., 2008) suggested that changes in the sedimentary patterns of continental siliciclastic successions cropping out along northern South America resulted through the combined action of regional tectonics (i.e., the Central America and South America collision) and tropical climatic changes.
The early closure of the Panama Seaway opens new questions about the evolution of the Inter-Americas fauna, specifically about the precise paths that controlled the Great American Biological Interchange. It also opens questions about the actual mechanisms triggering the expansion of northern hemisphere glaciers 3 million years ago.
According to Silva-Tamayo, the early closure of the Panama Seaway may explain some evolutionary pathways of marine life along the Caribbean, i.e., a major extinction and wipeout of Caribbean coral reefs between 13 and 10 million years ago.
In addition to Silva-Tamayo, the research team consisted of scientists from Washington State University, the Smithsonian Tropical Research Institute in Panama, and several universities in Colombia.