Tag Archives: Deccan Traps

It wasn’t just an asteroid that killed the dinosaurs

Scientists have now obtained enough solid data to confirm that the large extinction of the dinosaurs 65 million years ago was caused not just by the Yucatan asteroid impact but also by the gigantic volcanic event in India called the Deccan Traps.

The researchers said the asteroid strike occurred 66.04 million years ago, plus or minus about 30,000 years. They said eruptions in a region called the Deccan Traps were already underway at a lower intensity but dramatically accelerated after the asteroid strike as if the powerful impact triggered it. The dating method they used found this acceleration began within 50,000 years of the impact, but it could have been in the mere days, months or years afterward. “Within measurement error, they’re simultaneous,” said volcanologist Loÿc Vanderkluysen of Philadelphia’s Drexel University. “The two processes in tandem caused the extinctions,” added Paul Renne, director of the Berkeley Geochronology Center and a University of California, Berkeley geologist, who led the study in the journal Science.

Though many planetary scientists have discounted the Deccan Traps for decades, paleontologists have tended to favor it as a major factor in the extinction. This new study suggests that both were involved, which was the theory held by most of the more reasonable scientists in both fields. While many liked to push one or the other theory in the press, the better scientists considered both a possible factor and have been working to determine this possibility.

New data says volcanoes, not asteroids, killed dinosaurs

The uncertainty of science: A careful updating of the geological timeline has strengthened the link between the dinosaur extinction 66 million years ago and a major volcanic event at that time.

A primeval volcanic range in western India known as the Deccan Traps, which were once three times larger than France, began its main phase of eruptions roughly 250,000 years before the Cretaceous-Paleogene, or K-Pg, extinction event, the researchers report in the journal Science. For the next 750,000 years, the volcanoes unleashed more than 1.1 million cubic kilometers (264,000 cubic miles) of lava. The main phase of eruptions comprised about 80-90 percent of the total volume of the Deccan Traps’ lava flow and followed a substantially weaker first phase that began about 1 million years earlier.

The results support the idea that the Deccan Traps played a role in the K-Pg extinction, and challenge the dominant theory that a meteorite impact near present-day Chicxulub, Mexico, was the sole cause of the extinction. The researchers suggest that the Deccan Traps eruptions and the Chicxulub impact need to be considered together when studying and modeling the K-Pg extinction event.

The general public might not know it, but the only ones in the field of dinosaur research that have said the asteroid was the sole cause of the extinction have been planetary scientists.