Coral, Glaciers and Arctic Willow
You can see signs of 220 million years of climate change from Grey Mountain.
Canyon Mountain, more commonly known as Grey Mountain. Photo: John Meikle, Government
of Yukon
220 Million Years Ago…
Warm: The grey limestone rocks of Canyon Mountain, also known as Grey Mountain, to the southeast were formed in coral reefs that grew in a tropical sea.
2.6 million to 12,000 Years Ago…
Cold & Warm: Glaciers covered this area repeatedly during the last glacial age, when temperatures were as much as 5°C (9°F) colder than today. At the same time, to the northwest, Beringia was ice-free. Recurring glaciations scoured the surface of Grey Mountain, erasing traces of the previous glaciations and the warmer interglacials that separated them.
12,000 to 10,000 Years Ago…
Warm: As the temperature warmed, huge lakes of glacial meltwater formed near the shrinking glaciers. You are standing on the bed of Glacial Lake Champagne, a lake that may have extended as far as 200 km (125 miles) to the west. The white cliffs around Whitehorse are its exposed lake bottom silts. The glaciers also left chunks of ice and debris behind that melted slowly to form small pothole lakes and gently rolling land.
Brain coral fossil, Grey Mountain. Photo: Peter Long
Recent Past…
Warming Quickly: Low-growing alpine plants such as moss campion, blackish crazyweed and dwarf willows have colonized the soil that has collected among the rocks on the dry, cool, windswept mountaintop.
Left: Arctic willow. Photo: John Meikle, Government of Yukon
Right: Blackish crazyweed. Photo: Bruce Bennett
Will these plants be able to adapt to the warming climate, or will they be replaced as the alpine treeline moves higher?