Thinking Citizen Blog —Mountains of the World (V): The Rockies

Thinking Citizen Blog — Wednesday is Climate Change, the Environment, and Sustainability Day

Today’s Topic — Mountains of the World (V): The Rockies: the Laramide Orogeny, the Grand Tetons (Wyoming), Lake Moraine (Alberta)

Crossing the Rockies was no easy task for explorers such as the British Alexander Mackenzie (1793) and the Americans Lewis and Clark (1805). Nor for the settlers that followed them. Most of the highest peaks are in Colorado (78 of the top 100) followed by Wyoming (10), and New Mexico (6). The most photogenic stretches are the Tetons (Wyoming) and the Ten Peaks (Alberta). Experts — please chime in. Correct, elaborate, elucidate.

FROM NORTHERN BRITISH COLUMBIA TO CENTRAL NEW MEXICO

1."The current Rocky Mountains were raised in the Laramide orogeny from between 80 and 55 million years ago."

2. "For the Canadian Rockies, the mountain building is analogous to a rug being pushed on a hardwood floor: the rug bunches up and forms wrinkles (mountains). In Canada, the subduction of the Kula Plate and the terranes smashing into the continent are the feet pushing the rug, the ancestral rocks are the rug, and the Canadian Shield in the middle of the continent is the hardwood floor."

3. Farther south, the growth of the Rocky Mountains in the United States is a geological puzzle. Mountain building is normally focused between 200 to 400 miles (300 to 600 km) inland from a subduction zone boundary. Geologists continue to gather evidence to explain the rise of the Rockies so much farther inland; the answer most likely lies with the unusual subduction of the Farallon Plate or possibly due to the subduction of an oceanic plateau.” It is unclear why the angle of subduction was flatter than usual.

NB: The Rockies are distinct from the Pacific Coastal Ranges which stretch from Alaska to Mexico and include the Olympic Mountains, the Cascade Range, the California Coastal Ranges (of which there are three) and the Sierra Madre Occidental.

MORAINE LAKE AND THE VALLEY OF THE TEN PEAKS — Alberta

1. Located in Banff National Park in southwestern Alberta. Canada’s oldest national park (1885). Outside the village of Lake Louise.

2. “The lake, being glacially fed, does not reach its crest until mid to late June. When it is full, it reflects a distinctive shade of azure blue. The unique colour is due to the refraction of light off the rock flour deposited in the lake on a continual basis by surrounding glaciers.”

3. The color of the lake has also been described as turquoise or “blue green.” I have never been there. Have you? If so, how would you describe the color? Any photos to share?

THE TETONS IN WYOMING — the youngest of the Rocky Mountain ranges (6 to 9 million years)

1. Above a photography by Ansel Adams (1902–1984)

2. Located south of Yellowstone National Park in northwestern corner of Wyoming. Oriented north-south for a distance of 40 miles.

3. “The Snake River flows southward through the valley before turning to the west and entering Idaho.”

NB: Jackson Hole is the most famous ski resort near the Tetons. The town has been the site of countless films from 3 Bad Men (1926), to the Big Sky (1952) to Daces with Wolves (1990) and Django Unchained (2012).

Rocky Mountains

Teton Range

Jackson Hole

Moraine Lake

https://en.wikipedia.org/wiki/Rock_flour

Geology of the Rocky Mountains

Grand Teton National Park

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YOUR TURN

Please share the coolest thing you learned in the last week related to climate change or the environment. Or the coolest, most important thing you learned in your life related to climate change that the rest of us may have missed. Your favorite chart or table perhaps…

This is your chance to make some one’s day. Or to cement in your own mind something that you might otherwise forget. Or to think more deeply than otherwise about something dear to your heart.