12 December 2014
Friday fold: Miette slate, Alberta
Posted by Callan Bentley
Previously I’ve featured a road cut at the intersection of the Trans-Canada Highway and the Icefields Parkway as the Friday fold.
Here are some other look at cool features to be seen at this outcrop, including folds, but also including ripple marks, cross-bedding, graded beds, cleavage, and boudinage.
First, the general setting, showing bedding (both horizontal and moderately dipping) and cleavage (upright, subvertical):
Here’s a fold!
Zooming in on the most folded part:
A close look at one bed, exposed in cross-section…
…at the top are pyrite crystals:
Here’s a striking example of a graded bed:
Another primary structure that can be seen here is ripple marks, exposed on the bedding plane where it coincides with cleavage:
Boudinage deforms the stiffer, sandier-protolith layers (now quartzite transected by quartz veins):
Finally, here are a suite of GigaPan images that Aaron Barth and I shot at the site for additional exploration by you. Check out these features in dynamic context, and revel at the ensuing rush of insight:
Happy Friday, everyone.