A hydrothermal system near the coast of Mexico, caused by the same asteroid event that killed the dinosaurs, lasted 700,000 years after the impact, according to an April 8 international study involving UT researchers. The study will further the understanding of how marine life in the Chicxulub crater reacted to the asteroid and provide clues to how life may have started on Earth.
“Crater-produced hydrothermal systems are places that people are really interested in understanding because they are one of the places that life could have first developed on Earth,” said Chris Lowery, research assistant professor at the Jackson School of Geosciences and one of the researchers involved in the study.
The hydrothermal system was created when the asteroid hit the ocean floor and shattered the crust, Lowery said. A hydrothermal system is when ocean water seeps deeper down the crust, closer to the mantle, which heats up the water. In the Chicxulub system, the water heated up and collected osmium, a metallic element found in asteroids and ocean crust, and other minerals in the rocks and moved up to the surface. Then the osmium was deposited on the seafloor, which allowed the researchers to trace it in the samples, Lowery said.
When the asteroid hit the Chicxulub area, a plume of dust, soot and minerals high in sulfur blanketed the Earth, causing a global cooling event that caused 75% of life to go extinct, said Sean Gulick, a professor at the Jackson School of Geosciences and researcher in this study. Understanding the hydrothermal system is important to understanding how the ecosystem reacted to the asteroid, Gulick said.
“The whole ecosystem that developed in the subsurface is only there because of the hydrothermal system,” Gulick said.
Lowery said there is still some research needed to find the exact relationship between marine life and the hydrothermal system, but the study shows evidence for the hydrothermal system at the same time as high marine life productivity. He said this research will further the understanding of life after the asteroid impact.
“Regardless of what effect (the hydrothermal vent) had on plankton living up in the surface ocean — hydrothermal systems are really important for life on the seafloor,” Lowery said.
The researchers drilled 1,500 meters into the Chicxulub crater to collect samples of rock containing osmium to analyze how long the hydrothermal system was active, Lowery said.
The researchers chose to trace osmium because it exists in other parts of the world, making it easy to compare future studies, said Honami Sato, assistant professor at Kyushu University in Japan.
“It’s very important for future works to discuss the marine ecosystem after the impact event,” said Sato, the lead author of the study.
