21 May 2012
Up on Sulphur Mountain
Posted by Callan Bentley
Here’s the view riding up (or down) Sulphur Mountain, Banff, on the gondola:
As you can probably tell from the cable lines’ misalignment, this was a composite (stitched) photo. Mt. Rundle is in the background.
If you turn to the left, you can see Tunnel Mountain, south of the town of Banff:
Tunnel Mountain is interesting on a couple of levels. To a glaciologist, it’s a roche moutonée — a profound valley glacier flowed over it from left to right (west to east) during the Pleistocene:
Actually, Tunnel Mountain is a structural, along strike, Mini-Me twin of the much larger Mt. Rundle, which you can see here as it looks from Banff town:
Mt. Rundle is the namesake of the Rundle limestone, a Mississippian limestone that is a major ridge-former in the Canadian Rockies. Here’s what Mt. Rundle looks like from the top of Sulphur Mountain:
The asymmetry of Mt. Rundle is a surefire signal that its strata dip towards the southeast (toward Sulphur Mountain). Each of these mountains is a thrust sheet, like Sun River Canyon further along strike to the south, in Montana.
Back in the gondola, here’s a look at the spot where Tunnel Mountain takes its leave from Mt. Rundle…
…The Bow River slices right on through! I guess you’d call that a water gap, of sorts.
Here’s a “terrain” Google Map view of the area:
Up on top of Sulphur Mountain, we found tilted limestone. The rock dips to the southeast, like the strata of Mt. Rundle:
Note the differential weathering.
I really liked the intersection of the planes of bedding and the planes of railing shadows here:
The view to the southwest at Sundance Peak…
…That’s what you call a U-shaped valley.
We turned our gaze to the northwest, where we gazed back at where we had been hiking earlier that same day:
Zooming into the middle of that image, you can see distinctive Mt. Louis (the tower at right):
Leaving Sulphur Mountain via gondola, and looking to the southeast, we saw a rainbow:
Looking forward to returning to this spot in July… a lovely spot.
I’m glad the cables are misaligned due to stitching. Otherwise, your post would have involved much screaming and falling. That’s a beautiful place! I didn’t go up the gondola, but I climbed Tunnel Mountain when I was there in 2005. I was nervously watching for grizzlys the whole time (there had been an attack down the road that same week).
“Differential weathering” otherwise known as ‘terrapans structures’ (short-hand for ‘tear your pants’) further south in the Lodgepole of Montana.
[…] These are strata of the Sulphur Mountain Formation, part of the Triassic Spray River Group in Banff National Park. The outcrop is next to the parking lot for Bow Falls in the Banff townsite, where the Bow River cuts through Rundle Mountain to make Tunnel Mountain. […]