The stromatolites of Helen Lake 2: GigaPans

Posted this morning as my “Christmas gift” to blog readers in both photo and GigaPan form, here are the exquisite stromatolites of Helen Lake, Banff National Park, Alberta. [gigapan id=”159358″] link [gigapan id=”159462″] link [gigapan id=”159461″] link [gigapan id=”159459″] link [gigapan id=”159458″] link [gigapan id=”159355″] link [gigapan id=”159359″] link Finally, three other non-stromatolitic GigaPans from … Read more

More oncoids (from the Peyto Formation?)

Two years ago, I posted on some interesting structures my students and I saw at Consolation Lakes, near Moraine Lake in Banff National Park. They were little concretions, “oncoids” roughly speaking, and may have indicated (thanks Howard!) that the boulders were sourced to the Peyto Formation, a Cambrian carbonate within the Gog group: The purpose … Read more

Geomystery: what are these white lines?

Esteemed readership, I’ve got a mystery for you. What are these white lines, inclined consistently at a high angle to bedding? I picked up this sample below the “Wall of Death,” on the trail from Wapta Lake below Mount Wapta, en route to the Walcott Quarry of the Burgess Shale. The “zebra-striped” rock is of … Read more

Yamnuska

Driving west from Calgary, your first evidence of entering the Canadian Rockies’ Front Ranges is the startling sheer cliff of Yamnuska, north of the Trans-Canada Highway: Yamnuska’s shape is a function of differential weathering of the two rock units that make up the mountain: Cambrian Eldon Formation limestone, and Cretaceous shales of the Brazeau Formation. … Read more

Bedding / cleavage relations in the Stephen Formation, Yoho NP

Good afternoon! Here are a few photos, both plain and annotated, showing the relationship between primary sedimentary bedding and tectonic cleavage in the “tectonised Stephen” Formation atop the Cathedral Escarpment (in Yoho National Park), just northeast of the Walcott Quarry where the (thicker, basinward) Stephen Formation hosts the Burgess Shale. Weathering exploits both these planes … Read more

Friday fold: Contorted Rome Formation next to the Max Meadows Fault

My student Mercer Parker shot this one over to me the other day: Click to enlarge Those are the slim strata of the Rome Formation (a.k.a. Shady*), strongly deformed in the region adjacent to the Max Meadows (“M&M”?) Fault. Thanks, Mercer! _____________________________________________ * Will the real slim Shady please stand up?

Friday fold: differential weathering of carbonate intraclasts in mudstone

Howard Allen is the documentarian of this week’s fold: Howard writes that this is: Middle Cambrian Chancellor Formation rock with recessive weathering intraclasts(?). Hamilton Lake trail, Yoho National Park, British Columbia. My interpretation of this one is a little shaky–it was raining when I took the photo (in 1982) and I was hiking with a … Read more