Asteroid impact, volcanism were one-two punch for dinosaurs

[Demeter]

http://www.eurekalert.org/pub_releases/2015-10/uoc--aiv092315.php

Berkeley geologists have uncovered compelling evidence that an asteroid impact on Earth 66 million years ago accelerated the eruptions of volcanoes in India for hundreds of thousands of years, and that together these planet-wide catastrophes caused the extinction of many land and marine animals, including the dinosaurs.

For 35 years, paleontologists and geologists have debated the role these two global events played in the last mass extinction, with one side claiming the eruptions were irrelevant, and the other side claiming the impact was a blip in a long-term die-off. The new evidence includes the most accurate dates yet for the volcanic eruptions before and after the impact. The new dates show that the Deccan Traps lava flows, which at the time were erupting at a slower pace, doubled in output within 50,000 years of the asteroid or comet impact that is thought to have initiated the last mass extinction on Earth. Both the impact and the volcanism would have blanketed the planet with dust and noxious fumes, drastically changing the climate and sending many species to an early grave.

"Based on our dating of the lavas, we can be pretty certain that the volcanism and the impact occurred within 50,000 years of the extinction, so it becomes somewhat artificial to distinguish between them as killing mechanisms: both phenomena were clearly at work at the same time," said lead researcher Paul Renne, a UC Berkeley professor-in-residence of earth and planetary science and director of the Berkeley Geochronology Center. "It is going to be basically impossible to ascribe actual atmospheric effects to one or the other. They both happened at the same time."

The geologists argue that the impact abruptly changed the volcanoes' plumbing system, which produced major changes in the chemistry and frequency of the eruptions. After this change, long-term volcanic eruptions likely delayed recovery of life for 500,000 years after the KT boundary, the term for the end of the Cretaceous and the beginning of the Tertiary period when large land animals and many small sea creatures disappeared from the fossil record...

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[MisterP]

1. while the Elder Things and Yithians preferred wilderness management

http://castlegreifenghast.deviantart.com/art/Strange-Aeons-561522672

[longship]

2. Sounds like Gerta Keller.

Who is one of the only scientists on the planet who dismisses the asteroid in the Yucatan as the coup de grasse for the dinosaurs. Almost all the geologic evidence says it was the asteroid, whose iridium layer worldwide shows dinosaurs below and no dinosaurs above. And no unexplainable exceptions.

Gerta Keller soldiers on, but her opinion is in the minority.