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14 September 2012
Friday fold: Siim Sepp’s SS
Geoblogger Siim Sepp contributed this lovely fold. He says: I saw a nice fold in Ireland. I like it because it looks like SS to me which are my initials. If you want, you can post it as your friday fold. I haven’t used it yet in my blog. This small outcrop is in Donegal, NW part of Ireland. I accidentally stumbled upon it. The fold formed most likely during …
6 September 2012
Ribs & hackles
Concentric ribs with hackles on a joint face, quartzite (metamorphosed fine-grained quartz sandstone stained with hematite) from Waterton Lakes National Park, southern Alberta.
30 August 2012
Miette outcrop
Here’s a cool outcrop of the Neoproterozoic Miette Group. Most of the Miette is classified as “slate” and “gritstone,” through these particular exposures, on the Icefields Parkway south of Jasper, are fine-grained and lacking in slaty cleavage. They don’t seem to have been too metamorphosed at all right here, as Sebastian shows in this photo: You’re looking (obliquely) up at the bedding plane there, with the bed dipping towards your …
28 August 2012
Guest post: Red Rock Canyon
A guest post by Callan’s student Jacob Douma Traveling with Callan Bentley and Pete Berquist through the Canadian Rockies on their Regional Geology Field Course in July 2012, we were exposed to a variety of physiographic features. Among them, was Red Rock Canyon located 16 km from Waterton Townsite within Waterton Lakes National Park, Alberta. In this guest blog post, I’ll be talking about the canyon’s physiographic features and origins. …
2 August 2012
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”:
23 July 2012
Salt casts from Purcell (Belt) Supergroup rocks, Waterton National Park
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, …
6 July 2012
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 Park in southernmost Alberta: Here’s a fold on the side of a mountain on the …
26 June 2012
Leopard rock of the Yaak
After our “pre-honeymoon” sojourn to the Canadian Rockies last summer, Lily and I returned to the U.S. via Porthill, and then drove over to a place I’ve been wanting to visit for a long time: Yaak, Montana. Yaak (or “the Yaak“) is way up in the Kootenai National Forest, in way-way-way-northwesternmost Montana. We camped out nearby, and then in the morning, we rolled into “town,” and had breakfast (“make your …
5 June 2012
A clutch of amygdules
Callan presents a collection of well-exposed amygdules, seen along the Dark Hollow Falls trail in Shenandoah National Park, Virginia. These white dots on a green background are the signatures of (1) Iapetan rifting, and (2) Alleghanian metamorphism.
30 May 2012
Virginia geology on video: The Grenville Orogeny & the rifting of Rodinia
I’m playing around with Microsoft Expression screen capture for the book project I’m working on, and here is a video I worked up yesterday as a demonstration of this new way of telling a geologic story: The Grenville Orogeny and the rifting of Rodinia (opening of the Iapetus Ocean): [youtube=”www.youtube.com/watch?v=g6itZWD8bQc”] I’m frustrated by the way my voice keeps blowing out the microphone, and how often I say “um” and how …
Callan Bentley is Associate Professor of Geology at Piedmont Virginia Community College in Charlottesville, Virginia. He is a Fellow of the Geological Society of America. For his work on this blog, the National Association of Geoscience Teachers recognized him with the James Shea Award. He has also won the Outstanding Faculty Award from the State Council on Higher Education in Virginia, and the Biggs Award for Excellence in Geoscience Teaching from the Geoscience Education Division of the Geological Society of America. In previous years, Callan served as a contributing editor at EARTH magazine, President of the Geological Society of Washington and President the Geo2YC division of NAGT.