15 March 2011
Sugarloaf III: Tension gashes
Posted by Callan Bentley
Background geology of the Sugarloaf Mountain area. (March 2010)
Primary structures in the meta-sandstone of the Sugarloaf Mountain Quartzite. (yesterday)
Background on tension gashes. (August 2010)
Nice photos. On that second one, it looks like there’s a foliation cutting across the tension gashes – and you can almost see it extending into the grains surrounding. What do you think?
That’s a lineation, actually — the quartz crystals there are fibrous and grow perpendicular to the tension gash. Both of the first two photos show that feature, and you can make it out in many of the other photos too, as a preferred fracture orientation.
right! “lineation” – man, it’s been awhile. But yeah, that makes sense. thanks!