https://www.livescience.com/46312-popigai-crater-linked-eocene-mass-extinction.html
Russia's Popigai Meteor Crash Linked to Mass Extinction | Live Science
Jun 13, 2014 - New evidence implicates one of Earth's biggest impact craters, the Popigai crater in Russia, in a mass extinction that occurred 33.7 million years ago.
mass extinctionrussiameteorcrash
https://ntrs.nasa.gov/citations/19940007621
Age of Popigai impact event using the Ar-40 - Ar-39 method - NASA Technical Reports Server (NTRS)
The Popigai impact structure of central Siberia is the largest known impact crater in the Commonwealth of Independent States with an original diameter of some...