Cave system discovered under Montreal

[robkelk]

Pretty sure, yes. Montreal's in the middle of the part of North America often covered by ice during ice ages - sedimentary rocks tend to be put down in layers that way. The nearly 90° angles are also caused by the most recent Ice Age - look up "glacial tectonism" (and, if you aren't a geologist, be prepared to spend hours figuring out what they're talking about).