Advertisement

You are browsing the archive for 10 November 2011 - Mountain Beltway.

10 November 2011

Shear bands in the Grassy Portage Sill

Continuing now with the discussion of my pre-GSA meeting field trip to examine the structural geology of the Quetico-Wabigoon subprovince boundary within the Superior Craton of southern Ontario, Canada. Our penultimate stop on the second day of the trip was a roadcut exposing the gabbro of the Grassy Portage Sill. This is what it looks like: …Except where it doesn’t. In places, it looks like this, instead: Zooming in a …

Read More >>

1 Comment/Trackback >>