Tuesday, February 10, 2009

Folded Mountain, B. C.

My familiarity with Folded Mountain, most recently known as WoGE #158, is from several trips up and down the Alcan, or Alaska Highway, or Highway 97 (British Columbia): four trips through the Fort Nelson to Liard Hot Springs area, two each way.
toad And here, above, is the greater Fort Nelson to Liard Hot Springs region of British Columbia, Canada. Liard River is a tiny community at Mile 496 (HM) of the Alaska Highway; Liard Hot Springs, aka Liard River Hot Springs, is at Mile 497 (HM). I note the location of the hot springs on the image above - rather than that of Liard River - well, because the springs are a great place for a soak if you happen to be passing through.

Muncho Lake
is a lake inside Muncho Lake Provincial Park at Mile 456 (HM) - the lake actually takes up quite a bit of north-south mileage along the highway, but mileage is traditionally taken from a particular historic refueling stop. Toad River is a town, at Mile 422 (HM) on the Alaska Highway; The Poplars at Mile 426 (HM) is a nice place to stay, with large logs making up rustic cabins (late 1990's info). HM = historical milepost; actual miles and kilometers have changed with road changes.
munchoZooming in a bit above, we can see our particular area of interest better: Muncho Lake, the NNW-trending Sentinel Range of the northern Rocky Mountains, and Folded Mountain (link to topography provided by Ron Schott).
mtn1 Here's the Google Earth shot I considered using for WoGE #158. It's an image looking west, from one point on the highway where one can stop and take a photo.
mtn2 And this is what that image would look like at near ground level, just about what you would see while driving west on the Alcan.
pic1 A photo! Now we can begin to see why it is, at least locally, called Folded Mountain.
pic2 Folds!
pic3 Close-up of the same folds!
fold And closer still, from a postcard I probably bought back in 1998 at The Poplars.
signThis is the sign at the Folded Mountain turnout, right at the eastern base of the mountain, at mile 409/km 658 (current mile/km):
Originally, all the rock of the British Columbia Canadian Rockies lay flat on the shallow sea bed of the western continental shelf where it had accumulated grain by grain over a billion years. About 175 million years ago the continent of North America began to move westward, overriding the Pacific shore and colliding with the offshore chain of islands. The continental shelf was caught in the squeeze. The flat layers slowly buckled into folds like those you see here. As time passed, folded mountain ranges sprang up across British Columbia. By 120 million years ago, the Rockies were showing above the sea. They grew for another 75 million years, rising faster than erosion could tear them down - likely reaching Himalayan heights. Active mountain building ended in the Canadian Rockies some 45 million years ago. The peaks have since been eroded to a small fraction of their original size.
Additional and more detailed geological information can be found in the comments of my WoGE #158 post.

Some Geological References:


Wayfarer Scientista said...

hmmm...I have a picture of that very mountain from my last trip down that highway. Such a beautiful drive.

Silver Fox said...

Yes, you got a nice photo of some of the folds, along with the Stone Sheep, bear, the lake, and a lot of other places here. It's a great trip to make. I recommend it to everyone.