Armored mud balls
Ever seen an armored mud ball? In this post, Callan encounters a small herd of these geological oddities in a coulee in southern Alberta.
canada
What those geologists were looking at
Yesterday, I showed you a scene of geologists (including me) clustered around some (presumably interesting) outcrop. I asked what you thought we might be looking at. Howard Allen, a denizen of this part of the globe, immediately identified the scene as that of the downstream end of the Athabasca Glacier. Several people guessed that we … Read more
What are these geologists looking at?
Photo by Sarah O. Tune in tomorrow for the answer!
Weathering rind
A cobble of green Belt/Purcell argillite, exposed on the trail to Crypt Lake in Waterton National Park, Alberta, displaying a well-developed “weathering rind”:
Cottonwood trees being consumed by caterpillars
In Waterton Lakes National Park, Alberta, my students and I camped under the shade of cottonwood trees… But some of the cottonwoods’ branches were looking a little thin… Caterpillars were munching on their leaves. And some trees had been completely denuded by the voracious little larvae: All three photos are taken on roughly the same … Read more
Deformed carbonatite dikes in Cambrian slate, Yoho National Park, British Columbia
Callan’s Canadian Rockies field course visits an outcrop of Cambrian slate in Yoho National Park, British Columbia. Folded and boudinaged carbonatite dikes are seen.
Friday fold: Spray Mountain Group siltstone
Today, we return to Banff National Park, to the outcrops next to the parking area for Bow River Falls… Zoomed-in closer to the thinner layers at left: These strata (shale and siltstone) were laid down in the quiet aftermath of the Permo-Triassic extinction, as terranes colliding with the edge of North America (far to the … Read more
Athabasca Glacier panorama
Click through for a big version… That’s the Athabasca Glacier, crown jewel of the Icefields Parkway in Jasper National Park, Alberta, Canada. Its lateral moraines show well its retreat and “deflation” in recent years.
Tool casts from the Sulphur Mountain Formation of the Spray River Group, Banff
Yesterday I showed you salt casts; today I’ll share a different kind of cast: the infillings of small scorings in the sediment made by tumbling pebbles or sticks or other “tools,”tumbling down a current. These small gouges were later infilled from above by a younger deposit of sediment (frequently coarser in grain size). You’re looking … Read more
Close one!
Callan and his students narrowly miss being stranded in Banff National Park when a rainstorm triggers a mudslide that closes the TransCanada highway.
Structures seen at Floe Lake
A showcase of geologic structures observed between downpours of rain at Floe Lake, Kootenay National Park, British Columbia. Cleavage, bedding, folds, faults, and strain are all presented for the discerning structural reader’s edification and titillation.
Friday fold: scenes from the trail to Bertha Lake
Given that I’m leaving tomorrow for the Canadian Rockies, I’ve been inspired to look through some of my photos from last summer, and to realize how few of them I’ve blogged so far. So let me show you some folded things today that Lily and I saw the afternoon we arrived at Waterton Lakes National … Read more
Floe Lake hike
Last summer, my wife and I spent some time in the Canadian Rockies. One of the things we did was to take a three-day backpacking trip to Floe Lake, in Kootenay National Park, British Columbia. We picked a rough couple of days for hiking – We got a lot of Canadian Rockies precipitation out there: … Read more
Granite dikes that have been folded and boudinaged
It seems like a good morning to return to Ontario, and to the Archean shear zones exposed at the Quetico/Wabigoon subprovince boundary of the Superior Craton. Readers will hopefully recall that I spent several days absorbing structural goodness from these rocks on a field trip before the Minneapolis GSA meeting last fall. The trip was … Read more
Where I’ll be next week
I’m headed off Saturday to the Canadian Rockies for two weeks. My colleague Pete Berquist and I are leading a regional field geology course up there. It’s a new gig for both of us, and I’m sure the trip will be quite a learning experience. As I was preparing for the trip today, I drew … Read more
Up on Sulphur Mountain
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 … Read more
Hiking Cory Pass
Callan and his wife hike Cory Pass in Banff National Park, Canada, and encounter some geology, some solitude, and a spectacular landscape.
Clark’s nutcracker on Sulphur Mountain
Friday it was geese. Today, it’s a Clark’s nutcracker: The Clark’s nutcracker is a beefy alpine corvid (perching birds related to crows) of the American west. It’s a great bird in my mind, because if you’re looking at one, it means you’re up in the high country. It means you’re out where the good stuff … Read more
Veins perpendicular to foliation
To recap the week so far here on Mountain Beltway: On Monday we looked at some sweet vertical boudinage along the plane of tectonic cleavage (not to mention those folds in a (formerly) horizontal granite dike, now bearing vertical axial planes), and then on Tuesday we looked at a horizontal cut through that same outcrop, … Read more
Deformed pillow basalts from southern Ontario
Have you ever seen Archean pillow basalts? How about Archean pillow basalts that have grown much taller through vertical extrusion along a ductile shear zone? Come to the southern Superior Craton to see more!