[Rockhounds] Asteroid that doomed the dinosaurs halted a key process for life

[Kreigh Tomaszewski]

The age of the dinosaurs ended 66 million years ago when a city-size
asteroid struck a shallow sea off the coast of what is now Mexico.

But exactly how the mass extinction of 75% of the species on Earth unfolded
in the years that followed the cataclysmic impact has remained unclear.

Previous research suggested that sulfur released during the impact, which
left the 112-mile-wide (180-kilometer-wide) Chicxulub crater, and soot from
wildfires triggered a global winter, and temperatures plunged.

However, a new study published Monday
<https://www.nature.com/articles/s41561-023-01290-4> in the journal Nature
Geoscience suggests that fine dust made from pulverized rock thrown up into
Earth’s atmosphere in the wake of the impact likely played a greater role.
This dust blocked the sun to an extent that plants were unable to
photosynthesize, a biological process critical for life, for almost two
years afterward.

“Photosynthesis shutting down for almost two years after impact caused
severe challenges (for life),” said lead study author and planetary
scientist Cem Berk Senel, a postdoctoral researcher at the Royal
Observatory of Belgium. “It collapsed the food web, creating a chain
reaction of extinctions.”

https://www.cnn.com/2023/10/30/americas/asteroid-dust-dinosaur-extinction-photosynthesis-scn/index.html