Visit volcanic deposits, landslide rubble and more in southern Alberta

With scorching temperatures expected this weekend, what could be better than hopping into an air-conditioned vehicle and going for a road trip through Alberta?

Calgary geologist Dale Leckie, author of The Scenic Geology of Alberta: A Roadside Touring and Hiking Guide has suggestions for what to visit.

He joined The Homestretch on Thursday to share some of these landscapes and explain how they came to be.

Crowsnest volcanics 

Volcanoes are very rare in Alberta's history, but west of Coleman in Crowsnest Pass, you can see deposits of an ancient volcanic explosion, said Leckie.

More than 100 million years ago, a volcano exploded where Cranbrook, B.C. is now.

"The best way to describe it is it just wreaks havoc on the landscape," said Leckie.

Superheated gases — estimated to be 1,000 C — flowed down the volcano slope, instantly charring trees. Deposits from the eruption covered 1,800 square kilometres and were buried kilometres deep.

As mountains formed, those deposits were pushed 90 kilometres to where they are now exposed in Crowsnest Pass in a place called Iron Ridge.

Frank Slide

In the middle of the night on April 29, 1903, Crowsnest Pass shook.

Turtle Mountain, long called "the mountain that moves" by Blackfoot people, let loose with Canada's largest landslide.

"It only took it took 100 seconds for all those rocks to come plummeting down, and it left a layer of boulders almost 45 metres thick," said Leckie.

"The debris went down into the valley and up the other side of the slope, which is pretty amazing."

The rubble, largely unmoved today, destroyed half the mining town of Frank and killed more than 90 people. It created a lake in the valley and covered the road and railroad.

Canadian Pacific Railway brought in 1,100 men to clear the tracks in 17 days, but it took three years to rebuild the road, said Leckie.

The landslide was caused by geologic processes.

"Those rocks there have been folded, bent, thrust, pushed on top of one another," said Leckie. "And when that happens, they get fractured, they get broken up, they get weakened."

The Alberta climate's freeze-thaw cycles also helped to loosen the rocks.

Legend of the Lost Lemon Gold Mine

In the mid-1800s, two trappers named Blackjack and Lemon discovered a rich deposit of gold. Some say it was east of the Continental Divide, others say it was west, in B.C.

But after they found it, Lemon killed Blackjack with an axe and became unstable. He wandered to Montana and told his story, but anyone who searched for the mine — Lafayette French, King Bearspaw, John McDougall, the Blackfoot woman Cloudwalker — searched in vain.

"There's also supposedly a curse for those who search for the gold," said Leckie, with people befallen by sudden death, firestorms and illness. 

From a geologic perspective, said Leckie, up and down the Rocky Mountains from Bragg Creek to Montana, there are a series of cliffs made of an unusual conglomerate, or cemented gravel.

It contains distinctive rock types that come from east-central British Columbia, with pebbles from ancient volcanoes and granites. Importantly, it also contains gold — though the location of the fabled mine is still unknown.

With files from The Homestretch.