21 March 2013

Slicks in Cub Sandstone

Posted by Callan Bentley

During Alleghanian deformation (late Paleozoic), the Cub Sandstone we looked at yesterday was tilted to near vertical at Catherine Furnace. The shale layers developed cleavage at this time, and there was evidently some flexural slip between sandstone layers, to judge from these fine slickensides:

Students: Can you deduce the sense of motion from the orientation of the structures in this sample? (Hint: note the directions the “steps” face…)