First Snowball Earth
Transition from Archean to Proterozoic Eons
2.5 billion years ago
La Cloche Mountains Mrspaceweb.jpg

The high-standing ridges of the Lorrain Formation of the La Cloche

Mountains and the lake-filled valleys of the easily eroded rocks of the

Gowganda Formation. The transition from the Archean to the Proterozoic Eons runs between them.  (Photo by Mrspaceweb)

La Cloche Mountains Ryan Hodnett.jpg

La Cloche Mountains (Photo by Ryan Hodnett)

La Cloche Mountains Mensilater.jpg

Quartzite ridges of the Lorrain formation on the La Cloche Silhouette Trail (Photo by Mensilater)