You are browsing the archive for 2012 July.
31 July 2012
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.
27 July 2012
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 west) began shedding clastic sediment into the basin to the east. The lack of critters …
26 July 2012
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.
25 July 2012
Here’s your macrobug of the week: a male dobsonfly we encountered last weekend, while making houseguests some pizza. What a beast! Envelope for scale: Adding a finger (not too close) for scale: A better perspective on the envelope, with a shirt button thrown in too: Lola looks intimidated as she contemplates this insect through the screen door: Houseguest from Nevada says, “You have some big bugs in Virginia!”
24 July 2012
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 at the bottom of a bed here: These are strata of the Sulphur Mountain Formation, …
23 July 2012
I’ve previously mentioned the lovely salt casts that can be found in Mesoproterozoic argillites of the Belt (“Purcell” in Canada) Supergroup of the Canadian Rockies (including the North American portion of the Canadian Rockies: Glacier National Park and the Sevier fold and thrust belt immediately south of it). When I led my Rockies field class students over Alderson Pass / Carthew Summit in Waterton Lakes National Park, Alberta, last week, …
22 July 2012
Callan and his students narrowly miss being stranded in Banff National Park when a rainstorm triggers a mudslide that closes the TransCanada highway.
15 July 2012
One year ago today, Lily and I had a fantastic wedding week in Montana. To celebrate the year we’ve been together since then, today I’ve got a gazillion photos to share – reliving the week for those who were there, and sharing it with those who weren’t able to make it… Our first group hike: Spanish Peaks: Cookout at Dave and Stacey’s place: Our second group hike: Sacagawea Peak: Norris …
9 July 2012
Mountain Beltway reader “Earth Mama” responded to the recent geo-meme (which started here, folks!) by compiling all these visit-worthy locations in a single Google Earth KMZ file. If reading the lists from the various geobloggers didn’t whet your appetite, now you’ve got the ‘virtual globe’ option…. Hi Callan, I wanted to thank you for the geosites post–it’s obviously generated a lot of activity in the geoblogosphere, and it inspired me …
7 July 2012
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.