Topper site in middle of comet controversy

(Phys.org)—Did a massive comet explode over Canada 12,900 years ago, wiping out both beast and man in North America and propelling the earth back into an ice age?

Long-lost Lake Agassiz offers clues to climate change

Not long ago, geologically speaking, a now-vanished lake covered a huge expanse of today's Canadian prairie. As big as Hudson Bay, the lake was fed by melting glaciers as they receded at the end of the last ice age. At its ...

Impact hypothesis loses its sparkle

Shock-synthesized diamonds said to prove a catastrophic impact killed off North American megafauna can't be found.

Charcoal evidence tracks climate changes in Younger Dryas

A new study reports that charcoal particles left by wildfires in sediments of 35 North American lake beds don't readily support the theory that comets exploding over the continent 12,900 years ago sparked a cooling period ...

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